Hydroxyapatite (CaHA) and poly-L-lactic acid (PLLA) are known as the "twin stars" of regenerative materials. These two biomaterials are widely used in the biomedical field and have become indispensable components in modern medicine. Whether for fracture repair, dental implants, skin regeneration, or fat reduction and body contouring, their presence can be seen. These two regenerative materials exhibit significant differences in composition, physicochemical properties, biological performance, and application areas.Components and StructureHydroxyapatite (CaHA): With the chemical formula Ca₁₀(PO₄)₆(OH)₂, it is primarily composed of calcium and phosphorus. It is a naturally occurring inorganic mineral found in bones and teeth, sharing similar composition and structure with bone tissue.◎ Poly-L-lactic acid (PLLA): Its chemical formula is (C₆H₈O₄)n, which is a synthetic linear aliphatic polyester made by polymerizing L-lactic acid monomers into a degradable high molecular material.Physical and chemical propertiesBiological performanceApplication AreaOverall, apart from cosmetic and plastic surgery, hydroxyapatite is more suitable for applications requiring osteoconductivity and bone replacement, while poly-L-lactic acid is better suited for biodegradable drug carriers and tissue engineering scaffolds.Applications of Composite MaterialsSince CaHA and PLLA have their own advantages and disadvantages, they are often combined to form composite materials to compensate for the shortcomings of single materials. CaHA/PLLA composites combine the osteoconductivity of CaHA with the biodegradability of PLLA and are widely used in bone tissue engineering and bone repair materials. By optimizing the composite ratio and structural design, both excellent mechanical and biological properties can be achieved. The CaHA/PLLA composite material, made by combining the two, can leverage their respective advantages to meet more complex clinical needs.

Bone repair materials primarily refer to materials used to directly support, enhance, or replace damaged bone tissue. The design and application of these materials focus on the treatment and restoration of bone, such as fracture healing, bone defect filling, and bone enhancement. Examples include naturally derived bone graft materials (e.g., autografts and allografts), synthetic ceramics (e.g., hydroxyapatite and tricalcium phosphate), metals (e.g., titanium and its alloys), and biodegradable materials (e.g., polylactic acid and polyglycolic acid).Orthopedic biomaterials is a more general term that encompasses all biocompatible materials used in orthopedic surgery and treatment. In addition to the functions of bone repair materials, these materials may also be used to support, replace, or repair other tissues such as tendons, cartilage, and muscles. From fracture repair to joint reconstruction, from cartilage repair to tendon regeneration, each step of the treatment process may involve one or more specific biomaterials.This article will provide a detailed introduction to seven major types of orthopedic biomedical materials, which include:Bone substitute materials: These materials are used to replace or repair damaged bones and are designed to mimic the structure and function of natural bone.Bone graft materials: encompassing various materials from autologous and allogeneic to xenogeneic bone grafts, used to fill bone defects or enhance bone healing.Cartilage substitutes and graft materials: designed specifically for repairing or replacing damaged cartilage, these materials help restore joint function and reduce pain.Tendon tissue substitutes and graft materials: Used to repair or replace injured tendons, these materials need to possess high elasticity and strength to support dynamic loads.Orthopedic internal fixation materials: including various nails, rods, plates, and other devices used for the internal fixation of fractures or in bone reconstruction surgeries.Orthopedic external fixator brackets and applications: These devices stabilize fractures or correct deformities through external brackets, and the design of the brackets should accommodate the specific needs of the patient.Orthopedic bioabsorbable internal fixation materials: These materials gradually degrade and absorb within the body, eliminating the need for a second surgery to remove them, while providing sufficient initial strength to support bone healing.Here is the direct translation of the provided text:"The following is excerpted from the '2025 Global Orthopedic Medical Devices Innovation White Paper': " 01Bone substitute materialsBone substitute materials, also known as bone graft substitutes or bone regeneration materials, are used in orthopedic and dental surgeries to replace natural bone. These materials are designed to support, enhance, or promote the regeneration and repair of damaged or missing bone tissue. The primary function of bone substitute materials is to provide a scaffold structure that encourages the formation of new bone, which eventually replaces or integrates with the newly formed bone tissue. ▌Here are some typical products in various categories:Bone Screws: Used to fix fracture fragments or as lag screws to hold fracture pieces together, common types include PDLLA/HA composite absorbable bone screws and metal titanium alloy bone screws.▲ Bone ScrewBone plates: closely attached to the bone to provide fixation, used in conjunction with screws for internal fixation of fractures, such as straight and irregular metal bone plates, as well as special-shaped bone plates like herringbone, arc-shaped, L-shaped, etc.Metal irregular-shaped bone plateIntramedullary nails: used for internal fixation of fractures, especially long bone fractures, such as V-shaped intramedullary nails, cloverleaf intramedullary nails, and interlocking intramedullary nails.Universal Retrograde Intramedullary Nail SystemSpinal implants: used for spinal stabilization and fusion, including interbody fusion devices, spinal fixation systems (such as pedicle screw systems), artificial intervertebral discs, etc.Different shapes of polyether ether ketone spinal fusion devicesArtificial joints: hip joints, knee joints, shoulder joints, elbow joints, ankle joints, wrist joints, finger joints, etc. Among them, artificial hip joints and artificial knee joints are the most developed and widely used.Common Total Knee ProsthesisThese orthopedic implants have a wide range of applications in clinical practice. They help restore the structure and function of bones by providing stable fixation and support. With advancements in biomaterials and manufacturing technologies, the design and materials of these implants are continuously optimized to improve their biocompatibility, mechanical properties, and ability to promote bone healing.The main characteristics of bone substitute materials include:Biocompatibility: The material should not cause adverse reactions or immune rejection in the host body.Bioactivity: Some bone substitute materials possess the ability to promote the proliferation and differentiation of bone cells, thereby accelerating the regeneration of bone tissue.Plasticity: The material should be easy to shape or customize to adapt to the specific anatomical structures and surgical needs of different patients.Mechanical properties: The material should have sufficient strength and toughness to support bone tissue growth, while its elastic modulus should be close to that of human bone to prevent stress shielding effects.Biodegradability: Many bone substitute materials are designed to be naturally degraded and absorbed in the body, so that they can be replaced by newly formed bone tissue over time. 02Bone graft materialsBone is a natural biocomposite material with an intricate hierarchical structure (Figure 4-2-1). Calcium phosphate minerals can account for 60% to 70% of the bone weight, while 90% to 95% of the organic phase is collagen, along with small amounts of non-collagenous proteins, polysaccharides, lipids, etc. Bone grafts can be classified into two major categories based on material source: natural materials and synthetic materials; based on the source of the graft, they are divided into autografts, allografts, xenografts, and artificial bone material grafts. Bone graft materials are primarily used in orthopedic surgery for indications such as bone fracture repair, coating of bone implants, revision of artificial joints, and injectable bone graft materials for treating osteoporosis. In spinal treatment, they are mainly used for indications like posterior spinal fusion and various spinal bone defects. In dentistry, they are primarily used for indications such as tooth extraction trauma and maxillofacial surgery. Bone graft materials are biomedically engineered materials used to repair or replace damaged bone tissue. These materials are designed to fill bone defects or provide structural support for bone tissue, promoting bone healing and regeneration. Bone graft materials can be autologous (from the patient's own bone tissue), allogeneic (from the bone tissue of other individuals of the same species), xenogeneic (from other species, such as cows or pigs), or synthetic (artificially manufactured materials).Natural bone grafts:Natural bone grafts are commonly used materials in orthopedic and dental surgeries for repairing or reconstructing bone defects and injuries. These materials are derived from natural sources, providing excellent biocompatibility and bioactivity. The following is a detailed introduction to natural bone grafts, including the characteristics and applications of autografts, allografts, xenografts, and naturally derived bone materials.Autologous bone, allogeneic bone, and xenogeneic boneAutograftAutologous bone grafting refers to the transplantation of bone from one part of a patient's body to another. This type of graft is considered the ideal bone grafting material due to its optimal biocompatibility and osteogenic capacity, as it does not trigger an immune response. Autologous bone grafting can be further divided into non-vascularized autologous bone grafting and vascularized autologous bone grafting. Non-vascularized grafting is relatively simple to perform and thus was adopted early in clinical practice. With advancements in microsurgical techniques, vascularized grafting was developed, which involves vascular anastomosis to maintain adequate blood supply to the graft, preserving its regenerative potential. This significantly improves the success rate of the graft and enhances the quality of autologous bone transplantation. Common sources for non-vascularized autologous bone grafts include the ilium, tibia, and calvaria. For vascularized autologous bone grafts, commonly used sources include the scapular osteocutaneous flap, fibular osteocutaneous flap, latissimus dorsi osteocutaneous flap, and iliac osteocutaneous flap.Advantages: No immune rejection reactions, high osteogenic capability.Disadvantages: The bone graft site may develop complications, such as pain and infection; the available bone quantity is limited.AllograftAllogeneic bone is derived from another individual of the same species, typically from a donor. This type of bone graft performs well in terms of osteoconductivity and can retain a certain degree of osteoinductivity after processing. Sources for allogeneic bone include: (1) bone tissue from amputated limbs; (2) ribs removed during thoracic surgery; (3) bones from fresh cadavers, with cartilage often used from deceased infants. Bone tissue from patients with tumors, infectious diseases, bacterial infections, skeletal disorders, or blood diseases is prohibited for collection. Depending on the type of graft, allogeneic bone transplantation can be classified as allogeneic bone grafting, allogeneic cartilage grafting, or allogeneic bone joint grafting. Based on different processing methods, there are fresh allogeneic bone, banked bone, and demineralized bone matrix gelatin. Allogeneic bone transplantation can avoid some of the drawbacks of autologous bone transplantation, but the main issues are the risks of rejection and cross-infection. Therefore, allogeneic bone needs to be processed before use, with the purpose of reducing or eliminating its immunogenicity. However, various processing methods may cause varying degrees of damage to, or even the death of, the bone cells in the allogeneic bone. The osteobiological effects of allogeneic bone in the host site mainly manifest as osteoconductivity and osteoinductivity. After processing, allogeneic bone becomes dead bone and gradually gets absorbed upon contacting the host bone bed. New bone growth occurs through this absorption process, where the allogeneic bone is "creeping substituted" by osteoblasts from the host bone and periosteum, resulting in the formation of new bone.Advantages: can be used for large bone defects and provides good mechanical support.Disadvantages: may trigger immune reactions, risk of disease transmission; requires strict screening and processing.Processing methods include fresh bone, deep-frozen bone, and freeze-dried bone. Freeze-dried bone (lyophilized bone) is generally preferred due to its lower immunogenicity.XenograftXenograft bone refers to bone material derived from other species. These materials need to undergo special processing to reduce immune responses and the risk of disease transmission. The main sources of xenograft bone materials include bovine bone, porcine bone, deer bone, sheep bone, etc. Among these, porcine and bovine bone materials are more readily available and have been studied the most in xenograft bone research. Currently, a relatively consistent view on xenograft bone is that both immune reactivity and osteoinductive activity share a common material basis; eliminating antigenicity also destroys the substances that induce bone formation. Therefore, pure xenograft bone cannot resolve the contradiction between eliminating antigenicity and maintaining osteoinductive activity. Combining the bone-active substances of de-antigenized xenograft bone to produce composite xenograft bone can partially restore the osteoinductive capability of xenograft bone, thereby addressing some of the difficulties brought about by this issue. This approach has become a new direction in xenograft bone transplantation research. For example, xenograft bone combined with bone morphogenetic protein (BMP), xenograft bone combined with autologous red bone marrow, xenograft bone combined with bone matrix gelatin, as well as xenograft bone combined with various growth factors.Advantages: Widely available, suitable for applications that do not require high mechanical strength.Disadvantages: The issues of immune response and biocompatibility are more prominent and require meticulous handling.Bone-derived materialsIn the field of bone repair and regenerative medicine, bone-derived materials play a crucial role. These materials are extracted and processed from natural biological tissues to obtain materials with specific biological functionalities. They can mainly be divided into bone scaffold materials and bone matrix materials, each with their unique advantages and potential applications. Below is a detailed introduction to these materials.Bone scaffold materialCalcined Bone: Calcined bone is produced by subjecting heterologous or allogeneic bone to high temperatures, removing organic components (such as fats and proteins), and primarily leaving behind the inorganic component hydroxyapatite.Advantages:Excellent biocompatibility: High-temperature treatment thoroughly removes potential antigenic substances.Disadvantages:Brittleness: The calcination process may affect the mechanical strength of the material, making it fragile.Lack of osteoinductivity: High-temperature treatment destroys the bioactive components in natural bone.Coral Hydroxyapatite (C.HA): Derived from marine coral, it is transformed through physical and chemical methods into a material mainly composed of calcium phosphate and calcium carbonate. Advantages: Similar to the porous structure of human bone: Its structure mimics the cancellous structure of human bone, which is conducive to the growth of new bone. Suitable for bone ingrowth: The pore size is suitable for the inward growth of new bone.Drawback: Limited mechanical properties, although it has certain compressive strength, its tensile and shear strengths are relatively low. Bone matrix materialDecalcified Bone Matrix (DBM): It mainly consists of demineralized bone collagen and other extracellular matrices. Its advantages are as follows: Promoting bone healing: rich in growth factors and components that stimulate blood vessel growth.Wide application: It is commonly used as an adhesive, mixed with other bone substitutes to enhance the overall performance of the composite material.Application: Commonly used as an autologous bone graft extender or mixed with other materials such as hydroxyapatite. Decellularized Bone Matrix: The protein components in xenogeneic bone are removed through chemical methods, while hydroxyapatite and natural bone structure are retained. Its advantages are as follows:Good biocompatibility and mechanical properties: preserves the three-dimensional porous network system of natural bone.Low antigenicity: almost completely remove antigenicity, reducing the risk of immune response.Its disadvantages are as follows:Lack of osteoinductivity: The processing may damage active osteogenic substances. These bone-derived materials each have unique characteristics and are widely used in bone repair and regeneration treatments in orthopedics and dentistry. The selection of suitable materials depends on specific clinical needs, anticipated biological functions, and the patient's particular circumstances. With advances in materials science, more efficient and biologically active novel bone-derived materials may be developed in the future. ▌Synthetic bone graft: Synthetic bone grafts play an increasingly important role in modern medicine, particularly in orthopedic and dental surgeries. The development of these materials aims to mimic the functions of natural bone while avoiding some of the limitations and risks associated with autologous and allogeneic bone grafts. Synthetic bone grafts can be roughly classified into inorganic bone graft materials, organic bone graft materials, and composite bone graft materials based on their composition and properties. 1. Inorganic bone grafting materialsInorganic bone graft materials are mainly divided into two categories: metal filling materials and ceramic filling materials. Metal filling materials are widely used in the manufacture of artificial joints and implant fixtures due to their excellent mechanical properties and ease of processing. Common materials include stainless steel, titanium and titanium alloys, cobalt-based alloys, and nickel-titanium alloys. These metal materials play a crucial role in orthopedic implants owing to their high strength and good biocompatibility. On the other hand, ceramic filling materials are mainly used for bone grafts, including alumina ceramics, hydroxyapatite, and bioglass, among others. These materials not only possess excellent mechanical properties but also exhibit high inertness to bodily fluids. Particularly, calcium phosphate ceramics, such as hydroxyapatite, have received widespread attention and in-depth research due to their outstanding biocompatibility and osteoinductive capacity. Calcium phosphate bioceramics are one of the early widely used bone filling materials and have been proven to effectively promote bone healing, providing both osteoconductive and osteoinductive properties. 2. Organic Bone Graft MaterialsIn the field of organic bone graft materials, ultra-high molecular weight polyethylene is widely used in wear-resistant implants such as hip and knee joints due to its excellent mechanical properties. Among polyacrylate materials, poly(methyl acrylate) (PMA) and poly(methyl methacrylate) (PMMA) are particularly prominent. Poly(methyl methacrylate) (PMMA) is similar in composition to the organic glass commonly used in daily life. The polymerization reaction of PMMA generates significantly more heat than glass polymers, reaching 78-120°C. It is crucial to protect the tissues in contact with PMMA during surgery to avoid thermal damage or even burns that could lead to tissue necrosis. PMMA is widely used in joint replacement surgeries for bonding prostheses and autologous bone. Dihydrate calcium sulfate, due to its fast curing speed, is often made into an injectable form. When using it, attention should be paid to ensure that the calcium sulfate adheres closely to the viable outer or inner periosteum of the bone so that it can serve as a bone-conductive matrix for vascular ingrowth. Calcium sulfate dissolves and is resorbed in the body within 5 weeks. Based on this characteristic, calcium sulfate can be used as a slow-release carrier for antibiotics in the treatment of osteomyelitis. Composite bone graft materialsIn the research of composite bone graft materials, mineralized collagen-based composite artificial bone and glass polymer materials have shown promising clinical application prospects. Composite bone graft materials that have been extensively studied include mineralized collagen-based composite artificial bones and glass polymer compounds. Mineralized collagen-based artificial bones are bone graft products synthesized at room temperature with components and structures similar to those of natural bones, providing effects close to those of autologous bones. This material features a porous structure with high porosity, which facilitates cell attachment and growth. Its primary components are type I collagen and hydroxyapatite crystals. The nanoscale size and specific crystal orientation of these crystals endow the material with excellent biocompatibility and degradability. Additionally, its strength is adjustable, making it suitable for clinical procedures and shape customization. The material has four prominent characteristics: Firstly, the material has a porous structure with high porosity, which facilitates cell crawling, attachment, growth, proliferation, and the transport of nutrients. Its mineral phase consists of low-crystallinity, nano-scale carbonate-containing hydroxyapatite, which grows uniformly on a collagen matrix. These characteristics theoretically give the material an inherent ability to bond with bone. Implants made from this material can provide a suitable environment on their surface to promote collagen and mineral deposition as well as osteoblast adhesion. Once osteoblasts adhere to the implant surface, subsequent bone growth occurs under cellular regulation. The main components of the material are type I collagen and hydroxyapatite crystals, which meet the physical and chemical requirements for in vivo implantation. It exhibits excellent biocompatibility and degradation properties, with a degradation rate matching the speed of osteogenesis. Additionally, the degradation process does not cause changes in the pH of the surrounding bodily fluids. Thirdly, the hydroxyapatite grains in the material are very fine, with nanocrystalline dimensions, and the C-axis of the hydroxyapatite crystals is parallel to the long axis of the collagen fibers, similar to the structure of natural bone material. In contrast, ordinary hydroxyapatite bone substitutes have larger crystal sizes, making them difficult to be absorbed and degraded by osteoclasts. Even after long-term implantation in the body, they are hard to be absorbed and replaced. However, the smaller hydroxyapatite grains make them easier to be absorbed and degraded by osteoclasts. Fourthly, the strength of the composite material is close to that of cancellous bone and can be adjusted as needed, making it easy to shape with a surgical knife and highly convenient for clinical use. Clinical usage indicates that it has good biocompatibility with the human body, no immune rejection reactions, and favorable healing outcomes, making it a safe and effective new bone graft material. Calcium sulfate-based composites, through the combination with organic polymers or inorganic ceramics, not only enhance their mechanical strength but also maintain good bioactivity, making them a powerful tool for treating diseases such as osteomyelitis. Mechanical properties refer to the mechanical characteristics exhibited by materials under various external loads (tension, compression, bending, torsion, etc.) in different environments (temperature, medium, humidity). Studies have shown that after compounding calcium sulfate with organic polymers or inorganic ceramics, its mechanical strength can be effectively improved, ranging between cortical bone (90~230MPa) and cancellous bone (2~45MPa). ▲ 3D reconstruction images of mature sheep vertebral bone defect filling and repair surgery at 0~36 weeks post-operation Calcium sulfate forms a stable structure with organic polymers primarily through chemical bonds. In the research by Lewis et al., magnetic resonance detected new chemical bonds formed between -COOH and calcium ions in CS/carboxymethyl cellulose composites. For different carboxymethyl cellulose contents (5%, 7.5%, 10%), the flexural strength of the composites increased by 99%, 103%, and 124%, respectively; the compressive strength of the 7.5% and 10% groups increased by 88% and 85%, respectively. Gao et al. also found that -COOH forms chemical bonds with calcium ions when CS is compounded with polylactic acid. Scanning electron microscopy showed that calcium sulfate (with a content of less than 50%) was uniformly dispersed in the polylactic acid matrix. When the CS content was 40%, the compressive strength reached its maximum at 82 MPa. Calcium sulfate and inorganic ceramic materials primarily form stable structures through physical connections, with the mechanical strength of the composite being influenced by the type of materials, crystal phases, and proportions. The structure of calcium sulfate/hydroxyapatite is mainly maintained by the calcium sulfate matrix, with hydroxyapatite simply integrated into it. Therefore, as the calcium sulfate content decreases, the mechanical strength tends to decline. Among all the crystal phases of calcium sulfate, hemihydrate calcium sulfate can rapidly self-cure into the harder dihydrate calcium sulfate through hydration, which is of significant importance for early weight-bearing in clinical bone defect reconstruction. Composite materials not only provide structural support and osteoconductivity, but also exhibit certain osteoinductive properties, and perform better in terms of immune rejection responses. The development and application of these materials have greatly enriched the options for bone repair, enhancing the flexibility and effectiveness of treatments. Through ongoing research and technological advancements, synthetic bone graft materials will play an increasingly crucial role in future medical applications. Tissue-engineered bone Tissue engineering bone is an advanced medical technology that combines principles of biology, engineering, and medicine to construct new bone tissue in vitro for the repair of bone defects. This technology primarily involves three core elements: seed cells, biomaterial scaffolds, and growth factors. Seed cells are the basic units used for tissue reconstruction, typically derived from the patient themselves or donors, to ensure biocompatibility and reduce immune rejection responses. Biomaterial scaffolds provide a three-dimensional porous structure that not only supports cell attachment and growth but also helps maintain cell distribution and transport nutrients. Growth factors are crucial elements that promote cell proliferation and differentiation, aiding in accelerating tissue formation and maturation. In tissue engineering, biomaterials used can be broadly classified into natural biomaterials and synthetic biomaterials. Natural biomaterials such as collagen, hydroxyapatite, and gelatin, due to their excellent biocompatibility and biodegradability, can effectively support cell adhesion, proliferation, and differentiation, and are generally non-toxic and have no side effects on the human body. The primary advantage of these materials is their ability to provide a biochemical and biophysical environment similar to that of human cells, thus promoting the formation and integration of new tissues. However, the main limitations of natural materials lie in their poor processability and reproducibility, as well as the difficulty in precisely controlling their degradation rate, which may present certain challenges in clinical applications. In comparison, synthetic biomaterials such as polylactic acid, polyglycolic acid, and polycaprolactone offer a wider range of choices and better processability. The biodegradation rates of these materials can be adjusted as needed, and their mechanical properties can be designed to meet specific clinical requirements. Synthetic materials are generally less expensive and have better reproducibility, making large-scale production easier. However, their main drawback compared to natural materials is their poorer biocompatibility and cell affinity, which may limit their effectiveness in certain clinical applications. Although the development of tissue-engineered bone has not been long, it has already demonstrated significant potential and promising applications. By optimizing the design of scaffold materials, improving the processing methods of seed cells, and enhancing the application strategies of growth factors, future tissue-engineered bone is expected to play a more critical role in the field of bone repair and reconstruction. The continued advancement of this technology will not only help overcome the limitations of traditional bone grafting methods but may also provide more effective solutions for treating complex bone defect cases. 03 Cartilage replacement and transplantation materials Cartilage is a special type of connective tissue, composed of cartilage cells (called chondrocytes), fibers, and matrix, with important physiological functions and structural characteristics. The structure of cartilage enables it to withstand pressure and serves as an important component of the skeletal system. Chondrocytes, also known as chondrocytes, are typically round or oval-shaped and are located in small cavities called lacunae. These cells are responsible for forming fibers and secreting the matrix, playing an active role in cartilage growth and maintenance. The region surrounding the chondrocytes in the lacunae is rich in chondroitin sulfate and is called the chondron. This structure helps protect the cells and facilitates material exchange with the surrounding matrix. Fibrous cartilage membrane: The exterior of the cartilage is wrapped in a layer of fibrous cartilage membrane, which is a type of tougher connective tissue that provides additional support and protection. It helps the cartilage bear loads and connect with adjacent bone structures. Extracellular matrix: The extracellular matrix of cartilage is its main component, consisting of collagen, proteoglycans, hyaluronic acid, and liquid-phase components such as water and electrolytes. This complex network not only supports the chondrocytes but also provides the necessary microenvironment for cell growth. The high water content of the matrix and the properties of hyaluronic acid allow substances to freely permeate through the matrix, providing nutrients to deep chondrocytes even in avascular conditions.  Based on the composition and structure of the matrix, cartilage can be divided into three types: hyaline cartilage, elastic cartilage, and fibrocartilage. Transparent cartilage is the most common type of cartilage, and its main chemical components are proteoglycans, particularly long chains of hyaluronic acid, with many shorter proteoglycan side chains attached to them. These side chains are mainly chondroitin sulfate, which bind to type I collagen fibers, forming a mesh-like structure capable of withstanding pressure. Transparent cartilage does not have periodic cross-striations or form distinct bundles of collagen fibers, but its structure is sufficient to withstand considerable pressure and tension.Elastic cartilage contains a large amount of elastic fibers, giving it greater flexibility and elasticity. This type of cartilage is mainly found in the ears and laryngeal structures.Fibrocartilage contains a higher amount of collagen fibers, providing greater support and resistance to tension. It is primarily found in areas that endure heavy pressure, such as the meniscus in the knee and intervertebral discs. In general, these components and properties of cartilage enable it to effectively withstand pressure and bending, while providing crucial structural support in joints and the skeletal system. In clinical practice, repairing cartilage defects primarily involves various methods, including traditional surgical techniques and newer biotechnological approaches. Traditional methods such as subchondral bone drilling and microfracture techniques stimulate the bone marrow to release stem cells, promoting natural cartilage repair. Procedures like joint debridement and lavage, as well as arthroscopic abrasion arthroplasty, are mainly used to remove fragmented tissue within the joint and smooth the joint surface, reducing pain and improving function. In some cases, severe joint damage may require artificial joint replacement to restore joint function. In the field of biotechnology, tissue transplantation techniques, such as autologous or allogeneic cartilage transplantation, utilize healthy cartilage tissue to fill defective areas. Autologous chondrocyte transplantation is a more refined method, involving the extraction of cells from the patient's own cartilage, expanding these cells in the laboratory, and then injecting them back into the defective area, typically under the protection of an autologous periosteal seal. One of the most advanced methods is tissue engineering technology, which combines elements such as seed cells, scaffold materials, and growth factors to culture and construct specific cartilage tissues in the laboratory before implanting them into the damaged area. This approach not only provides repair materials but also promotes cell proliferation and differentiation through growth factors, thereby accelerating the cartilage regeneration process. 1. Periosteum and cartilage membrane replace articular cartilage:The periosteum contains abundant nerves and blood vessels, providing nutritional and sensory functions, and contains multipotent hematopoietic stem cells and mesenchymal stem cells, which have the potential to differentiate into cartilage. Studies have shown that the periosteum, when implanted at sites of articular cartilage defects, can promote the formation of hyaline cartilage and subchondral bone. Despite the advantages of easy harvesting and minimal damage to the body, its clinical application is limited by difficulties in fixation, limited sources, and inability to fully meet physiological mechanical requirements. Autologous or allogeneic cartilage and chondrocyte transplantation to replace articular cartilage.Autologous chondrocyte transplantation is a method that involves obtaining healthy chondrocytes from the patient's own non-weight-bearing areas, which are then cultured and expanded in vitro before being implanted into the damaged cartilage area. This method has been shown to maintain the integrity of the subchondral bone and to inhibit fibrosis caused by fibroblasts. Allogeneic chondrocyte transplantation shows similar repair effects to autologous chondrocyte transplantation, but immune response and cell preservation are its main issues. 3. Alternative materials for artificial cartilage:Artificial cartilage replacement materials should possess good biomechanical properties, excellent lubricity and wear resistance, chondrocyte growth induction, strong bonding with the bone base, and biocompatibility. Currently used highly elastic materials such as silicone rubber, polyurethane, and polyvinyl alcohol hydrogel each have their own advantages and disadvantages. For instance, silicone rubber is prone to aging and failure, and the degradation performance of polyurethane needs improvement. The research focus is on improving existing materials and preparation processes, as well as exploring new materials. 4. Engineered CartilageTissue-engineered cartilage is achieved through the combination of seed cells and biological scaffolds for cartilage regeneration. Ideal seed cells for cartilage tissue engineering should have the following characteristics: Easy to obtain, abundant in source, and causes minimal damage to the organism.Strong proliferation ability in vitro culture.It has good adhesion to the bracket material.The seeded cells can adapt to the internal environment of the human body and maintain the characteristics of original chondrocytes. Current research mainly focuses on autologous chondrocytes, allogeneic chondrocytes, mesenchymal stem cells, and embryonic stem cells. The selection of scaffold materials includes both naturally sourced biomaterials and artificially synthesized scaffold materials. The key lies in the design of the scaffold and the correct choice of materials to ensure the mechanical stability of the scaffold and promote the proliferation and migration of seeded cells. 04 Tendon Tissue Substitutes and Transplant Materials Tendons are a typical type of regular dense connective tissue, whose primary function is to connect muscles to bones, thereby transmitting force during muscle contraction to move the bones and accomplish various body movements. The structure of tendons is closely related to their function and is mainly composed of three parts: collagen bundles, tendon matrix, and tendon cells. Collagen bundles: These are the main components of tendons, consisting of a large number of collagen fibers arranged in parallel. This arrangement of fibers gives tendons a high resistance to stretching, allowing them to withstand the forces generated by muscles.Tendon gelatin: It is the matrix filled between collagen fibers, containing proteoglycans and water, helping the tendon maintain structural stability and elasticity when subjected to pressure.Tendon cells: mainly composed of fibroblasts and stromal cells, are distributed between collagen fibers, responsible for synthesizing and secreting collagen and other matrix components, maintaining the structure and function of tendons.Since tendons need to withstand high tension, they endure significant stretching loads during movement. Overuse, intense exercise, or external accidents (such as cuts or crushing injuries) can all lead to tendon damage. Common injuries include tendon tears or ruptures; if left untreated, these injuries can result in permanent functional impairment or disability. The self-repair ability of tendons is very limited, primarily because tendons have relatively poor blood supply, resulting in a slow healing process that often fails to fully restore their original structure and function. In clinical practice, severe tendon injuries may require surgical repair, including suturing torn tendons or using grafts to replace damaged portions. Tendon injuries are common sports injuries, especially in cases of high-intensity or repetitive muscle use. Modern medicine has developed various methods for tendon injury repair and replacement, primarily including autologous tendon transplantation, allogeneic tendon transplantation, xenogeneic tendon transplantation, and artificial tendon substitutes. Autologous tendon transplantationAutologous tendon transplantation involves using other healthy tendons from the patient's own body for repair. The main advantage of this method is the avoidance of immune rejection, as the transplant material comes from the patient themselves. In the early 20th century, Kirschner and other scholars confirmed the feasibility of this method through studies on using autologous tendons for defect repair. However, the main disadvantage of autologous tendon transplantation is the limited availability of tendon resources, and the extraction of tendons may damage the donor site, which sometimes can lead to tearing due to insufficient strength at the donor site. 2. Allograft tendon transplantationAllograft tendon transplantation uses tendons from the same race but different individuals, expanding the pool of tendons available for transplantation. However, studies have shown that this method has a relatively high failure rate, with major issues including necrosis and rejection of the implanted tendon. Additionally, there is a risk of donor-transmitted viral infections, such as hepatitis and AIDS, which limits its clinical application. 3. Heterogeneous Tendon TransplantationHeterologous tendon transplantation utilizes tendons from different species. This method theoretically provides an abundant source of tendons, but immune rejection and biocompatibility issues remain significant challenges. Although chemical treatments such as the use of polyformaldehyde, freezing, and glutaraldehyde can reduce the immunogenicity of tendons, these processing methods may alter the biomechanical properties of the tendons, affecting the repair outcomes. Artificial Tendon Substitute Artificial tendon substitutes cover a wide range of materials, including alloys, plastics, nylon, and synthetic fibers. The design of these materials aims to mimic the function of natural tendons. However, many attempts have failed due to inadequate mechanical properties or poor compatibility with surrounding tissues. For example, carbon fiber artificial tendons were initially considered promising but were ultimately abandoned due to issues such as inability to absorb, stress relaxation, and severe adhesion problems. Currently, researchers are exploring new materials and technologies, such as human hair keratin artificial tendons and tissue-engineered artificial tendons, in hopes of improving the performance and biocompatibility of artificial tendons.  1. Human Hair Keratin Artificial Tendon (HHKAT)Human hair keratin artificial tendons utilize human hair keratin as raw material, undergoing special biochemical processing to form a biomaterial suitable for tendon repair. The main advantages of this material include: Good biological adaptability: Human hair keratin artificial tendons have good biocompatibility, able to gradually undergo tendon-like transformation in the body and integrate without significant adhesion to surrounding tissues.No immune rejection response: Due to special treatment, this artificial tendon does not trigger an immune rejection response in the body.Persistent mechanical properties: no attenuation of tensile stress, able to withstand long-term muscle movement traction.Tendonization Engineering: The process of being absorbed in the body while simultaneously forming new autologous tendons is referred to as tendonization engineering. The development of this material marks an important advancement in artificial tendon technology, particularly in enhancing the functionality of tendon repairs and reducing surgical complications. 2. Tissue-engineered artificial tendonsTissue-engineered artificial tendons utilize a combination of tendon seed cells and biodegradable materials. After in vitro cultivation, they are implanted into the defect site to promote the proliferation and differentiation of tendon cells, ultimately forming new tendon tissue. The main advantages of this method include: Naturalized repair at a high level: The formed tendon tissue is vibrant and functional, capable of achieving permanent replacement.Morphological and functional perfection reconstruction: It can be shaped according to the specific morphology of the defective tendon, achieving a highly matched morphological repair and functional reconstruction.No immune response or pathogen transmission risk: The seed cells used can be autologous cells, reducing the risk of immune rejection and disease transmission. The key to tissue engineering technology lies in selecting appropriate seed cells and scaffold materials, as well as effectively combining the seed cells with the scaffold materials. The scaffold materials must not only possess good mechanical strength to support early activity but also degrade in sync with cellular function, providing space for cell growth and physiological function. 05 Orthopedic internal fixation materials  Fixture type Description Translate the above content from Chinese to English and output the translation result directly without any explanationPurposemetal fixatorSteel plates and screws: used for fixing long bone fractures, such as the femur, tibia, and humerus.Nail-rod system: For example, femoral intramedullary nail, used for femoral fractures.Surgical wires and pins: used for fixing small fractures or bones.Fracture fixationNon-metallic fixatorPolymer Fixtures: Such as screws and plates made of polylactic acid (PLA) and polyglycolic acid (PGA), these materials are biodegradable and do not require a second surgery for removal.Ceramic fixator: used for filling bone defects, such as calcium phosphate (e.g., hydroxyapatite).Fracture fixation, especially in cases requiring biodegradable materialsBiological FixatorBone grafting: using autologous bone or allogeneic bone to fill bone defects.Bone morphogenetic proteins: Such as bioactive materials and growth factors, used to promote bone regeneration.Bone defect filling, promoting bone regeneration and bone healingHybrid Material FixatorComposite materials: Combining metals with polymers, ceramics, or bioactive substances to leverage the advantages of various materials.Complex fracture fixation situations requiring the combination of advantages from different materials. In fracture treatment, internal fixation technology is a key method for restoring stability at the fracture site. It allows for early weight-bearing and limb activity, thereby promoting fracture healing. The choice and application of internal fixation involve multiple factors such as the type of fracture, patient age, and expected prognosis. For the stability of the fracture, the influence of the following five main forces needs to be considered: Compressive force: Transmitted axially, increases bone loading, commonly seen in compressive fractures of the spine.Tension: Similarly transmitted through the axial direction, leading to fracture separation.Bending force: causes one side of the bone to bear pressure while the opposite side bears tension.Torsional force: A force that causes bones to withstand rotational stress.Shear force: caused by compressive force, leading to oblique fractures. To ensure the effectiveness and safety of orthopedic internal fixation materials, the materials used must meet the following key conditions:  1. Having sufficient strengthInternal fixation devices must have sufficient strength to support the load during the fracture healing process. The characteristics of different materials are as follows: Stainless steel: It has good mechanical properties and cost-effectiveness, is easy to process, and is widely used in the manufacture of various internal fixation devices. It has relatively high bioactivity but may corrode in high-load environments.Cobalt-chromium-molybdenum alloy: low bioactivity, extremely high corrosion resistance and mechanical strength, but high cost and difficult processing.Titanium alloy: lightweight, highly corrosion-resistant, with excellent biocompatibility and low bioactivity. The elasticity of titanium alloy is similar to that of human bone, making it suitable for manufacturing long-term implants. It produces almost no artifacts in CT and MRI scans, facilitating follow-up examinations.Polylactic acid-based degradable materials: Good biocompatibility, can naturally degrade into water and carbon dioxide after use, eliminating the need for secondary surgery to remove them. Suitable for internal fixation scenarios that do not bear high loads. Their long-term biosafety is still under research. 2. Unorganized responseThe material should be biocompatible, not causing toxic reactions, inflammation, fibrosis, or macrophage activation. These biological responses may lead to pain, swelling, and dysfunction in the implantation area, and in rare cases, may even result in tumor formation. Therefore, for young individuals, it is generally recommended to remove the internal fixation device once the fracture has healed. 3. No corrosionImplants should not rust or undergo electrolysis. When using stainless steel, it is important to ensure high purity and freedom from impurities to prevent corrosion. Additionally, measures should be taken to prevent contact between different internal fixation materials to avoid interfacial corrosion. Using internal fixation components made of the same material is also an effective method to prevent electrolytic corrosion. Evolution of Internal Fixation Techniques The AO/ASIF system is a classic internal fixation system created by Mueller and other orthopedic surgeons in 1956. The primary focus of this perspective is on achieving anatomical reduction and stability of fractures through internal fixation techniques to promote direct bone healing. The AO team developed a comprehensive internal fixation system, including screws, plates, intramedullary nails, and detailed surgical techniques and principles. The core principles of the AO perspective include:  Anatomical reduction of the fracture ends: Especially for intra-articular fractures, it is emphasized that perfect anatomical reduction must be achieved as much as possible.Strong internal fixation: Provide sufficient stability to meet biomechanical needs through a precisely designed internal fixation system.Non-invasive surgical techniques: During surgery, strive to protect the blood supply to the fracture site and surrounding soft tissues, minimizing additional damage caused by the procedure.Early mobilization: With stable internal fixation support, patients can start muscle and joint activities as soon as possible to prevent complications caused by prolonged bed rest. The AO perspective emphasizes that mechanical stability is the key to achieving fracture healing, and the precision of the operation and the quality of internal fixation directly affect the success of the treatment. The BO viewpoint, or Biological Fixation Concept, is a supplement and development of the AO viewpoint. It gradually formed in the late 20th century to the early 21st century, primarily emphasizing the importance of maintaining or restoring the biological environment and blood supply in the fracture treatment process. The BO viewpoint holds that excessive mechanical fixation may negatively impact the biological environment at the fracture site, such as stress shielding leading to osteoporosis and damage to soft tissues caused by the surgery itself. Therefore, the BO viewpoint proposes the following principles: Protect soft tissue and blood supply: Minimize interference with the fracture area and surrounding soft tissue during surgery, and maintain blood supply. Appropriate internal fixation: Use materials with good biocompatibility and low elastic modulus to reduce stress shielding on bones and promote fracture healing.Minimally Invasive Surgery Technology: Using minimally invasive techniques to reduce the impact of surgery on the patient's overall condition and accelerate recovery. Minimally Invasive Percutaneous Osteosynthesis (MIPO): In recent years, the development of minimally invasive surgical techniques aims to reduce damage to soft tissues during surgery, thereby preserving blood supply and promoting faster healing. With a deeper understanding of fracture treatment, the traditional concept of mechanical fixation has gradually shifted toward the concept of biological fixation. Biological fixation takes the following factors into account: Protect local soft tissues: Reduce the fracture away from the site to preserve the attachment of local soft tissues.Do not insist on anatomical reduction of fracture fragments in comminuted fractures: unless it is an intra-articular fracture, there is no need to pursue perfect anatomical reduction.Use biocompatible materials: such as low elastic modulus materials, to reduce contact between internal fixation devices and bones, thereby minimizing stress shielding effects.Minimize surgical exposure time: Strive to shorten the duration of the surgery to reduce the overall impact on the patient. 06 Orthopedic external fixator frame and application Orthopedic external fixators are medical devices used in fracture treatment and orthopedic surgeries to stabilize fractured areas or correct deformities through external scaffolding. They are fixed to the bone with pins or screws that penetrate the skin, while the external structure provides the necessary support and stability to promote fracture healing or correct bone deformities. External fixators are suitable for complex fractures where internal fixation is not possible, infections, or cases requiring progressive adjustments. A骨外固定器 is actually a third type of fixation method between internal fixation and external fixation in orthopedics, which partially immobilizes fractures or dislocations with minimal trauma. It combines the advantages of both internal and external fixation. Compared to internal fixation, it causes less damage and has a lower wound infection rate. Compared to external fixation methods such as splints and plaster casts, it provides more reliable and stable fixation. However, it also has its own shortcomings and drawbacks. Therefore, when choosing to use a bone external fixator, one should strictly adhere to its indications and contraindications. The external fixator primarily consists of fixation pins, connecting rods, and fixing bolts and nuts. The fixation pins are used to penetrate the bone and hold it, while the tail of the pin remains outside the body and is connected and fixed by the connecting rod. The types of fixation pins mainly include Steinmann pins, which are commonly used for lower limb fractures in adults; Kirschner pins, which are often used for upper limb fractures in adults and for upper and lower limb fractures in children; half-threaded pins (Schanz pins) with threaded tips, commonly used for half-pin fixation; and fully threaded pins, which are mainly used for full-pin fixation. The connecting rods serve to connect and fix the tails of the pins, with common types being tubular, threaded rod, and hook-groove styles. The fixing bolts and nuts mainly serve to connect the fixation pins and connecting rods.  Orthopedic external fixators can be classified based on their design, function, and intended use. The main types include: Unilateral external fixatorThe fixation device is located on one side of the fracture and fixes the bone fragments through connecting rods and pins.It is applicable for simpler fractures or when local skin conditions do not allow the use of circular or bilateral fixators. Bilateral or multi-side external fixatorDefinition: The fixation device is positioned on two or multiple sides of the fracture, providing more uniform support and stability through multiple connecting rods and pins.Application: Suitable for complex fractures or reconstruction surgeries that require more stable fixation.

In today's continuously advancing orthopedic medical technology, the application of new materials brings more hope to patients. Among them, ultra-high molecular weight polyethylene (UHMWPEThe material performs excellently in the field of orthopedic implants, becoming a reliable choice for both doctors and patients.In the field of artificial joint replacement, a material that seems ordinary.——Ultra-high molecular weight polyethyleneUHMWPE）However, it silently supports more than... globally every year.200Successful joint replacement surgeries in tens of thousands of cases. From hip joint liners to cranial repairs, this is stronger than steel.15But as light as plastic.'Magical materials'..., is breaking through the boundaries of medicine at an astonishing pace of innovation.I. Important Needs for Orthopedic ImplantsOrthopedic diseases are diverse, such as fractures and joint degeneration, which seriously affect the quality of life of patients. Orthopedic implants are designed to repair or replace damaged bones and joints, restoring their function. This requires the implant materials to have good biocompatibility, not to trigger immune rejection reactions in the body; they must also possess sufficient strength and wear resistance to withstand the pressure and friction generated by daily physical activities, ensuring the long-term stable performance of the implants.II. Unique Advantages of Ultra-High Molecular Weight Polyethylene1.Outstanding biocompatibility: Ultra-high molecular weight polyethylene "gets along well" with human tissues, and after being implanted in the body, it almost does not trigger the immune system's alert, significantly reducing the risk of rejection and minimizing unnecessary pain and complications for patients.2.Outstanding wear resistance: In joint replacement surgery, there is constant friction between the joint surfaces. Ultra-high molecular weight polyethylene, with its extremely low friction coefficient and exceptional wear resistance, can withstand long-term and frequent friction, extending the service life of the implanted joint and reducing the probability of reoperation.3.Good mechanical properties: It has high strength and toughness, capable of withstanding the pressure from body weight while also adapting to the dynamic mechanical environment of the bones to a certain extent. It is not easily broken, ensuring the stability of the implant.Three, specific applications in orthopedic implants1.Artificial Hip Joint: The hip joint is an important weight-bearing joint in the human body. The acetabular liner made of ultra-high molecular weight polyethylene, in conjunction with the metal femoral head, can simulate the movement of a natural joint, providing patients with hip joint diseases a good recovery of joint function, allowing them to walk and move freely again.2.Artificial knee joint: The knee joint has a complex structure and high requirements for implanted materials. Ultra-high molecular weight polyethylene is used for knee joint spacers, effectively buffering the impact during joint movement and improving joint mobility. Many patients with knee joint diseases experience a significant improvement in their quality of life after surgery.3.Other applications: In spinal fusion surgery and bone defect repair, ultra-high molecular weight polyethylene also plays an important role in helping patients reconstruct bone structure and restore health.IV. Development Prospects and ChallengesWith the advancement of technology, ultra-high molecular weight polyethylene materials are continuously optimized, and there is hope for the development of products with even better performance in the future, further expanding their applications in the field of orthopedic implants. However, there are still challenges, such as how to further enhance their bonding ability with bone tissue to achieve better bone integration, which remains a direction that researchers are striving to overcome.Ultra-high molecular weight polyethylene materials have achieved significant success in the field of orthopedic implants, bringing hope to countless patients. It is believed that with the joint efforts of researchers and medical professionals, it will make a greater contribution to the development of orthopedic medicine, allowing more patients to regain a healthy life.From being an unknown engineering plastic to saving millions of joints.'Life materials'，UHMWPEThe evolution of this is a model of biomedical materials science. With breakthroughs made by Chinese companies in the field of high-end medical materials, this...'Invisible champion'Promoting Chinese medical manufacturing to the world stage. Perhaps in the near future, we will see lighter, stronger, and smarter products.UHMWPEImplant, let'Lifetime use'No longer a dream.Shanghai Poly Medical Materials Co., Ltd. is committed to implant-grade ultra-high molecular weight polyethylene.Research and development, production, and sales of core medical raw materials such as UHMWPE (Ultra-High-Molecular-Weight Polyethylene), providing implant-grade ordinary UHMWPE profiles, highly cross-linked UHMWPE profiles, and other products. It also involves new material technology research and development, promotion, synthetic material manufacturing and sales, plastic product manufacturing and sales, and various other businesses.

Bone substitute materials, also known as bone graft substitutes or bone regeneration materials, are used in orthopedic and dental surgeries to replace natural bone. These materials are designed to support, enhance, or promote the regeneration and repair of damaged or missing bone tissue. The primary function of bone substitute materials is to provide a scaffold structure that facilitates the formation of new bone, which is eventually replaced or integrated by new bone tissue.Here are some typical products in each category:Bone screws: used to fix fracture fragments or as tension screws to hold fracture pieces together. Common types include PDLLA/HA composite absorbable bone screws and metal titanium alloy bone screws.Bone plates: closely attached to the bone to provide fixation, used in conjunction with screws for internal fixation of fractures, including straight and non-straight metal bone plates, as well as specially shaped bone plates such as triangular, curved, and L-shaped.The commonly used materials for orthopedic plates mainly include the following types:Stainless steel:With high mechanical performance and low price.The anti-corrosion ability in the body is generally poor.Cobalt alloys:More corrosion-resistant and almost completely inert to tissues.The mechanical properties are not as good as stainless steel.3. Titanium alloy:It has good toughness and fracture resistance.Good organizational compatibility, elastic modulus close to that of bone.The price is relatively high.4. Carbon fiber reinforced polyether ether ketone composite plate (CF-PEEK):Through technological innovation, carbon within the board layers is embedded in PEEK in different directions to form a new composite material.The elastic modulus has only slightly increased, but the stiffness and strength have greatly improved.According to different ratios of carbon fiber, they are divided into CF30, CF50, and CF60, which have been successively applied in the field of spinal trauma and other areas.Intramedullary nails: used for internal fixation of fractures, especially diaphyseal fractures of long bones, such as V-shaped intramedullary nails, flower-shaped intramedullary nails, and locking intramedullary nails, etc.Spinal implants: used for stabilization and fusion of the spine, including interbody fusion devices, spinal fixation systems (such as pedicle screw systems), artificial intervertebral discs, etc.The commonly used materials for spinal implants include the following:Metal materialsTitanium alloy: Titanium alloy is the mainstream metal material for manufacturing spinal interbody fusion devices, possessing good biocompatibility and biosafety. Additive manufacturing technology (3D printing) has accelerated the development of titanium alloy fusion devices, allowing for the adjustment of pore sizes to achieve an elastic modulus similar to that of bone, thereby improving bone integration.Porous tantalum metal: Porous tantalum metal fusion devices are also materials that have gained attention in recent years, characterized by good biocompatibility and the effect of biomimetic metallic bone trabeculae.2. Bioactive materialsCalcium phosphate materials: including hydroxyapatite (HA), β-tricalcium phosphate (β-TCP), and a mixture of both (biphasic calcium phosphate, BCP). These materials are commonly used for non-structural bone grafting.Bioactive glass (BAG): It has good bioactivity and can promote the regeneration of new tissues.Composite materials such as nano-hydroxyapatite/polyamide 66 composites (n-HA/PA66) and coral hydroxyapatite (CHA) are commonly used in intervertebral fusion devices, offering good biocompatibility and mechanical properties.3. Polymer MaterialsPEEK is currently the best material for intervertebral fusion devices and has to some extent replaced titanium, gaining widespread recognition among orthopedic surgeons. The characteristics of PEEK include a modulus of elasticity close to that of bone tissue, mechanical properties similar to cortical bone, minimal stress shielding, and good radiolucency, which facilitates imaging observation.Biodegradable materialsPolylactic acid: used to manufacture biodegradable interbody fusion devices, with a degradation rate that approximately matches the time required for bone tissue reconstruction and repair, exhibiting good biocompatibility.Artificial joint prostheses: artificial hip joint, artificial knee joint, artificial shoulder joint, artificial elbow joint, artificial ankle joint, artificial wrist joint, artificial finger joint, etc. Among them, artificial hip joint and artificial knee joint are the most developed and widely used.Common total knee prosthesesThe commonly used materials for artificial joint prostheses mainly include metal materials, polymer materials, and ceramic materials. The following are the specific applications and characteristics of these three types of materials:Metal materialsStainless steel: Although it was widely used in artificial joint prosthetics in the early days, it has gradually been replaced by more advanced materials due to the presence of elements, such as nickel, that may cause distortion.Cobalt-based alloys and titanium alloys: These materials have excellent mechanical properties and stability, and are gradually becoming the preferred materials for modern artificial joint prostheses.Polymeric MaterialsUltra-high molecular weight polyethylene: commonly used in the manufacture of joint surfaces, such as acetabular cup liners, it has excellent wear resistance, stress crack resistance, and self-lubricating properties. It is an indispensable material in hip and knee joint replacements.Other common polymer materials include polyether ether ketone (PEEK) and polymethyl methacrylate (PMMA).3. Ceramic MaterialsCeramics: Such as alumina and zirconia ceramics, which have good biocompatibility and low wear rate, but have high manufacturing costs and may exhibit brittleness in certain cases.These orthopedic implants have a wide range of applications in clinical practice, providing stable fixation and support to help restore the structure and function of bones. With advancements in biomaterials and manufacturing technology, the design and materials of these implants are continually being optimized to improve their biocompatibility, mechanical properties, and ability to promote bone healing.

Polycarbonate (PC), due to its excellent physical and chemical properties (such as high transparency, high strength, heat resistance, biocompatibility, etc.), has widespread applications in the medical field.Medical devicesDisposable medical suppliesSyringes, infusion sets, blood separators: Utilizing their high transparency and impact resistance, they facilitate the observation of liquid conditions, while also withstanding high-temperature sterilization (such as autoclaving or gamma radiation).Surgical instruments: Used for manufacturing non-cutting components (such as handles, housings), resistant to chemical corrosion and easy to clean.Reusable equipmentEndoscope housing, surgical light cover: High transparency and heat resistance ensure it does not deform during long-term use.Dialyzers, components of an extracorporeal membrane oxygenator: biocompatibility meets medical standards, preventing reactions with body fluids.2. Medical Equipment Housing and ComponentsMedical Equipment Protective Cover The shell used for ventilators, ultrasound equipment, MRI operating consoles, etc., combines the needs of lightweight, impact resistance, and electromagnetic shielding.portable medical devicesThe shells of oxygen generators, blood glucose meters, etc., are impact-resistant and can be disinfected through various sterilization methods.Simple stylePharmaceutical PackagingBottles, boxes, and blister packs: resistant to chemical corrosion, preventing medicines from moisture or contamination.Special storage containerUsed for storing blood samples and low-temperature containers for organ transplantation, resistant to low temperatures (-80°C) and with good sealing properties.4. Dental and Orthopedic ApplicationsTemporary dentures, orthodontic appliances Producing personalized dental models or aligners through 3D printing technology allows for rapid prototyping and low cost.Surgical GuideThe guide plate used for precise positioning in orthopedic surgery can be sterilized at high temperatures and reused.5. Ophthalmology RelatedGoggles, face shieldPrevents droplets and liquid splashes, high transparency without obstructing vision.Contact lens case, instrument lensScratch-resistant and not easily breakable, with high stability for long-term use.6. Sterilization AdaptabilityPolycarbonate can withstand various sterilization methods (autoclave, ethylene oxide, gamma rays) without degradation, making it suitable for reusable medical devices.7. Emerging Applications3D printing customized equipmentUsing medical-grade PC materials to print surgical models, personalized rehabilitation braces, etc.Intelligent medical device components The casing for wearable monitoring devices balances lightness with durability.Advantages SummarySafety: Complies with ISO 10993 biocompatibility standards, non-toxic and non-sensitizing.Durability: The impact strength is 200 times that of glass, reducing the risk of accidental breakage.Cost-effectiveness: Replacing glass or metal to reduce weight and production costs.LimitationsLong-term contact with strong alkaline solutions may lead to hydrolysis, and selection should be based on specific scenarios.Non-absorbable materials are not suitable for degradable implantable devices.The application of polycarbonate in the medical field continues to expand, showing significant potential especially in high-end equipment and personalized healthcare.

Recently, the U.S. Food and Drug Administration (FDA) approved a system for cleaning flexible endoscopes' complex internal channels for the first time. These channels are a stubborn source of hospital-acquired infections. This breakthrough was achieved by Nanosonics' automated CORIS device.According to reports, Nanosonics' CORIS device is specifically designed to address stubborn biofilms formed in the narrowest areas of endoscopes. These areas cannot be reached by manual scrubbing during conventional reprocessing. Residual material composed of patient cells may gradually develop resistance to high-level disinfectants over multiple cleaning cycles.An Australian company pointed out that studies on gastroscopes and colonoscopes found biofilm residues present in the fine channels of all devices, and some hospital-acquired infection outbreak events could be traced back to specific antibiotic-resistant strains carried within these reusable instruments.Previously, the FDA has urged medical technology developers and healthcare institutions to switch to using disposable components (such as endoscope tip covers) or fully disposable endoscope systems, and has been tracking instrument contamination and serious postoperative infection cases for many years.It is worth mentioning that Nanosonics' CORIS disinfection system has received de novo clearance from the U.S. FDA for medical devices, initially approving its use in conjunction with the Olympus Evis Exera III system, specifically designed for colonoscopy. At the same time, the company stated that it plans to gradually cover all major categories of flexible endoscopes.Michael Kavanagh, President and CEO of Nanosonics, stated in a statement: "The company is continuously advancing its commercialization preparations, including obtaining the necessary approvals in the UK, Europe, and Australia. These approvals are expected to be completed in the first quarter of the 2026 fiscal year." At that time, the company will initiate the first phase of its commercialization process, focusing on targeted hospital pilot programs."At the same time, we are preparing to submit our first 510(k) application for expanded indications to the FDA," Kavanagh added.It is estimated that 60 million endoscopic procedures are performed worldwide each year, with each operation relying on manual brushing and rinsing of the internal equipment, and more than half of these cases occur in the United States. In addition to CORIS, Nanosonics is also positioning itself in the ultrasound probe reprocessing equipment market through its Trophon series of products.The CORIS system can be installed above the sink and automatically injects patented formula friction cleaners into the endoscope channels, followed by air flushing to remove internal residues. According to the manufacturer's instructions, the outer surface of the endoscope still needs to be cleaned separately according to standard procedures.

Medical-grade chemical materials come in many types, primarily可分为高分子、金属、无机非金属及复合材料, and they are mainly applied in areas such as medical devices, drug carriers, implant equipment, and more. Note: The phrase "可分为高分子、金属、无机非金属及复合材料" is directly translated to maintain the original structure, but for better readability in English, it might be more appropriate to rephrase it as "primarily分为 polymers, metals, inorganic non-metallic materials, and composite materials".China has a large population and a vast and完善 medical system. The market size of medical materials has already exceeded one trillion yuan, with a compound annual growth rate exceeding20%Particularly in areas such as wound care and surgical consumables, large-scale application has already been achieved.However, high-end medical materials have一直严重依赖进口, such as ultra-high molecular weight polyethylene and halogenated butyl rubber.75%Dependent on imports.The production process of medical-grade materials and the international medical certification barriers severely restrict the localization process of medical materials.In the country“Fourteen Five”Under the promotion of the new materials special project,COC/COPMaterials such as biodegradable polylactic acid have achieved technological breakthroughs; however, the industrial chain is still not complete, including raw materials, key processes and equipment, and quality control.“Bottleneck”The problem urgently needs to be solved.Today, we will analyze the current status, challenges, and future pathways of domestic medical materials from the perspectives of technological breakthroughs and industrial upgrades.I, Medical chemical materials include which ones? (Note: The original Chinese sentence seems to be incomplete or incorrectly phrased. A more accurate translation of the intended meaning would be: "I. What are the types of medical chemical materials?")Classification of Medical Materials Medical chemical materials are a type of functional materials with special properties such as biocompatibility and corrosion resistance, widely used in medical devices, drug carriers, implantable devices, and other applications.According to material category, they can be roughly divided into three types.  Polymer materials (accounting for medical materials)60%): including polyurethane, silicone rubber, polylactic acid (PLA), polyether ether ketone (PEEK, can be applied in areas such as artificial organs and surgical supplies.  Inorganic non-metallic materials, such as bioceramics and glass, are commonly used in orthopedic and dental implants.  Metals and composite materials, such as titanium alloys and carbon fiber reinforced polymers, are commonly used in cardiovascular stents and high-load implantable devices.The market size is very large. 2024In 2023, the scale of China's medical device market has reached1090010 billion yuan, among which the market size for medical polymer materials exceeds3000Billion yuan, with a compound annual growth rate of31.55%。 Biomaterials have been listed as a national“Fifteen-fourteen”Key directions2024The industry's RD investment has also increased this year.8.2%Above all, the industrial chain upgrade driven by policies will accelerate.  II. Comparison of Production Patterns at Home and Abroad Current Status of International Monopoly High-end medical materials have long been monopolized by foreigners: ultra-high molecular weight polyethylene is mainly controlled by Celanese of Germany and DSM of the Netherlands.DSMMonopoly; The import dependence on halogenated butyl rubber (vaccine stopper material) exceeds70%。  Higher technical barriers: Medical-grade materials have strict requirements for molecular weight and impurity content (such as heavy metals).0.1ppmThe requirements for the ) products are more stringent than those for conventional products, and many production technologies, core catalysts used in reactions, and key production equipment are monopolized by international giants through patents.  Domestic technological breakthroughsMedical Polyolefin: Lanzhou Petrochemical has built the country's first clean production facility for medical polypropylene, and some grades developed can replace imported materials for upright infusion bags.  COC/COPMaterials: Acuity and TuoXing Technology have successfully broken through the synthesis technology of isoprene monomer.Acrylic thousand-ton level high transparency material (Cyclic olefin copolymer)COCThe production facility, which has been completed,24Production trials have already begun at the end of the year.TuoXian Technology Phase I3000ton/YearCOC/COPProduction facility2023year6Completed and put into production in the same month, the products have already started to enter the market, with a transparency rate of ().92%It has reached international standards and can be used in vaccine packaging and optical lenses.Biodegradable materials: Ordinary absorbable suture products can be produced on a large scale by domestic companies, such as polyglycolic acid and polylactic acid.PGLASutures and other items, the production cost is that of imported products.60%-70%。However, its products mainly focus on low to medium molecular weight products, and there is still a certain gap in the precise control of degradation speed and mechanical strength compared to imported products.III. Core Challenges in the Process of Domestication  Technical bottleneck Ingredients“Stranglehold”The dicyclopentadiene monomer is used for production.COC/COPMain raw material, high purity/Medical-grade materials are mainly reliant on imports, with companies like Mitsubishi Chemical and Mitsui Chemicals dominating the market.80%The above market share. Isobutylene monomer accounts forCOC/COPTotal cost of60%, resulting in relatively high production costs for enterprises; ultra-pure5NLevel (≥99.999%Quartz sand, which is an raw material for vaccine vials, has a domestication rate of less than 30%.20%。  Insufficient process accuracy: DomesticPLAThe degradation rate of sutures fluctuates within the range of.±20%Imported products can be controlled at.±5%Within the domestic range, domesticallyPLAFiber strength is0.6-0.8GPaFails to meet the standards of imported products.1.2GPa, resulting in low suture tension retention after surgery.The purity of domestic isobutylene monomer is99%Imported products can achieve99.9%, leading toCOCThe fluctuation range of transmittance is relatively wide.±2%Import±0.5%）。Medical Useα-The curing time deviation of domestically produced cyanoacrylate adhesives.±10Seconds, imports can already be controlled at±3Seconds.Market and Certification Barriers The international certification cycle for medical products is long.FDA、CEAuthentication takes approximately需要提供具体时间或者更多上下文以给出准确翻译。3-5In the year, the cost of certification exceeded ten million, and domestically there were only10%The company has passed the certification.  Medical Institution Usage Habit: Top Tertiary Hospitals in China90%For high-value consumables (such as artificial joints), imports are prioritized, while domestic products are placed in the second tier due to insufficient performance in biocompatibility, corrosion resistance, or mechanical strength.  Shortcomings in Industry Chain Coordination Insufficient upstream-downstream collaboration: For example, orthopedic materials need to match the corresponding surgical instrument design, but domestic companies have barely any.“Material-Device-Clinical”The joint RD system has led to a situation where even with suitable materials available, they cannot be practically applied.  Equipment relies on imports: continuous polymerization reactors, solid-liquid separation equipment, stripping equipment, crystallization equipment, high-precision injection molding machines, and other key equipment.90%Still requires imports. Some domestic companies can produce, but their performance, efficiency, adaptability, and after-sales service do not yet meet the standards of foreign companies.  Summary and Outlook Domestic medical chemical materials are already at “From quantitative change to qualitative change” The critical point in polyolefins,COC/COPMid-range products are already in mass production, and the situation of relying on imports for high-end products won't last much longer.With the strong support of national policies (such as“New Materials Special Project”Billion-dollar funds and the continuous iteration of technologies among production enterprises.AI+(nano-modification), expected2030The localization rate of high-end medical products is expected to increase to.60%That is all.

The polyurethane artificial blood vessels have shown localized 'snowflake-like' detachment of the anti-coagulation coating on their walls, which is no longer an isolated case. In the field of biomaterials, high-performance polymers such as polyurethane and silicone rubber possess excellent mechanical properties, but their 'slippery' surface characteristics often lead to the failure of functional coatings, making it as difficult as painting on an icy surface.One, Invisible Organic CompoundsImage source: Internet, infringement deletion.The paradox of biomaterials lies in the pursuit of perfect balance between strength and flexibility, which leads to a surface that tends towards "inertness." Just like a non-stick pan coated with Teflon, materials such as polyurethane and PEEK are inherently resistant to any intimate contact with coatings.Molecular-level "oil film": Residual demulsifiers from injection molding and silicone oil adsorbed during sterilization form a contamination layer 5-10 nm thick.The smooth trap: Mirror-like polishing reduces mechanical mating opportunities, with coating adhesion below 2 N/cm².Chemical apathy: The density of functional groups on the material surface is less than 5/μm², making it difficult to form stable chemical bonds. II. Vacuum Plasma, Weaving Capture Nets at the Atomic Scale1Supramolecular cleaning techniqueHigh-energy electron beams precisely bombard the molecular chains of pollutants, fragmenting them, which are then抽出由真空泵抽离。 （注：最后一句似乎在原文中不完整，因此我将其保留为“抽出由真空泵抽离”。 如果有更多上下文信息，可以提供完整的句子以便更准确的翻译。） 如果只需要翻译前半部分，那么答案将是：High-energy electron beams precisely bombard the molecular chains of pollutants, fragmenting them, which are then drawn away by a vacuum pump.The residual organic carbon content decreased from 1200 ppm to less than 50 ppm.2Topological Structure Revolution- Fabricate hexagonal pits in the range of 100-500 nm through reactive ion etching (RIE).The specific surface area increases by 17 times, creating a physical anchoring matrix for the coating.3Chemical Bond "Seeding Program"- Injecting oxygen-containing polar groups reduces the surface contact angle from 112° to 32°.The binding energy is increased to 8.3 times that of the untreated material. Survival Rules for Medical-Grade Surface Treatment1More demanding than manufacturing in healthcare.The surface roughness Ra of the equipment should be less than 0.2 μm to eliminate niches where microorganisms can hide.Fully compliant with the YY/T 0287 Medical Device Quality Management SystemDevelop a medical-specific tracing system, with automatic machine locking when parameter deviations exceed limits. Four, does your medical coating encounter these problems?Perhaps it's time to reassess the material surface when faced with these scenarios.The drug-eluting stent's controlled-release layer cracks and crystallizes after gamma ray sterilization.The antibacterial coating of absorbable sutures fails prematurely in vivo within 3 weeks.The cell affinity layer of the artificial cornea has micro-scale "blind spots". ConclusionFrom a 0.1μm coating gap on a synthetic blood vessel to a medical breakthrough impacting millions of patients' quality of life, the advancement of surface engineering has never been more crucial. In the long river of evolution in biomedical materials, Kunshan Puleisi wishes to be the ever-spinning "nanometer loom," weaving energy codes for every encounter between coatings and substrates.Kunshan Plestar, as a deep player in the field of surface treatment,始终保持对技术可能性的探索。Whether you are a materials engineer, a specialist researcher, or simply a technical enthusiast, welcome to explore the boundaries of plasma technology with us—because every process evolution may begin with an unanswered "why."

Speech TitleResearch and Development of Polyolefins and Their Modification Technologies for High-End Medical Devices ApplicationsGao MingDr. [Name], a senior engineer at the Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, serves as a member of the Surface Engineering Division of the Chinese Mechanical Engineering Society and a committee member of the China Medical Device Industry Association. Focusing on medical devices and energy electronics applications, he has long been engaged in the development of polymer material surface modification technologies. He has led or participated in more than 20 national, provincial, municipal, and enterprise-commissioned projects. He has published over 30 academic papers, holds more than 50 Chinese invention patents and over 20 PCT international patents, and has drafted and revised 2 national standards and 1 industry standard.In 2020, the first batch of baby boomers born after the founding of New China in the 1960s will officially enter the elderly population phase. As a group that possesses both purchasing power and internet awareness, as well as discerning consumption tastes and quality, they will be officially included in the medical insurance coverage system next year. This holds significant implications for the domestic medical system and the healthcare industry. Currently, with the continuous advancement of technologies such as new materials, 3D printing, and biomimetic materials, the demand for plastics in the medical device industry is also continually increasing.As early as the last century, most domestic medical devices used plastic materials that were primarily concentrated on disposable plastic medical products made of PVC and PS. Since 2010, with the continuous improvement of the domestic medical system and the internationalization of medical standards, medical plastic products made from PVC have gradually revealed performance deficiencies and have been increasingly replaced by new high-performance plastic materials made from PP.According to predictions by the China Medical Industry Information Center, the market size of medical devices in China will exceed 600 billion yuan in 2019, with an expected annual compound growth rate of 16.8%. This has been interpreted by the market as a signal that China's medical device industry is about to enter a golden decade. In terms of capital, investments in the medical device industry have already begun to take shape. At the beginning of the year, the three major internet companies, BAT, announced their formal entry into the medical device market, while Huawei Group also started competition in areas such as smart devices and medical internet technology. Driven by capital and technology, it is expected that the medical device market will experience a leap in 2020, and high-end medical devices will gain significant growth potential in this process.Currently, domestic refining and chemical enterprises mainly focus on increasing the investment and production scale of specialized materials while reducing the proportion of general materials. Leading companies have even exceeded 60% in the production ratio of specialized materials. The production of high value-added specialized materials leads to an optimized production structure and an improvement in the company's sales profit level.For the downstream demand of the high-end polyolefin products market, approximately 60% of the demand needs to be met through imports, while the self-sufficiency rate for high-end specialized materials is even lower, at less than 20%.In the next decade, as the proportion of the aging population continues to rise, the era of consumption upgrading for medical-grade polyolefin materials will arrive. Compared to the low profits and low demand of low-end general-purpose materials, the demand for high-end, high-performance polyolefins is likely to continue to grow.At present, the initial products of medical-grade PE, PC, ABS, and other plastics in our country still mainly rely on imports. However, in the areas of medical-grade PP and PE, some domestic enterprises have made breakthroughs in technology. Companies such as Lanzhou Petrochemical, Beifang JinHua, Maoming Petrochemical, Changling Refining and Chemical, Sino-Korean Petrochemical, and Yanshan Petrochemical have all mastered the key technologies for producing specialized medical materials and high-value-added polyolefin products.In 2014, Beihua Hua Jin Chemical Industry Group Co., Ltd. successfully developed a new transparent polypropylene RP344P-K, which passed the YY/T0242-2007 (Medical Infusion, Transfusion, and Injection Devices Polypropylene Special Material) test. As the first transparent polypropylene in Mainland China to pass this test, it will greatly promote the updating and replacement of medical transparent polypropylene in injection devices in China, and will also better meet the requirements for environmental protection in China, marking a milestone significance.Before 2015, domestic polyolefin pharmaceutical packaging materials relied almost entirely on imports, making the development of high-end medical materials urgent. In 2016, Lanzhou Petrochemical conducted a series of technical breakthroughs and production process modifications in the development of new medical materials, increasing production capacity from 31 tons per hour to 37 tons. RP260 and LD26D medical-grade polyolefin special materials became the high-end brand of Lanzhou Petrochemical's polyolefin products.In 2018, after more than three months of medical device biological evaluation, the medical polypropylene专用料 GA260R produced by Sino-Korean (Wuhan) Petrochemical Co., Ltd. recently obtained a test report issued by a testing institution under the State Food and Drug Administration. The chemical properties comply with the requirements of "Polypropylene Special Material for Medical Infusion, Blood Transfusion, and Injection Devices," and the biological evaluation is qualified, earning the entry pass into the medical industry.In March 2019, Maoming Petrochemical successfully trial-produced a new high-transparency impact-resistant polypropylene product, PPB-MT16, in the chemical distributed polypropylene workshop. This new product is mainly used for manufacturing disposable plastic syringe medical products and features simple packaging, convenience of use, resistance to breakage during use, and ease of processing and molding.In May 2019, the Chemical Department of Changling Refining and Chemical successfully conducted trial production of polypropylene non-woven fabric special material PPH-Y35X using the degradation method at its 100,000-ton polypropylene plant. The product quality meets international standards and can fully replace imported special materials.The medical non-woven fabric dedicated polypropylene resin PPH-Y35X developed by Luoyang Petrochemical has been able to replace foreign brands, and it is also the first Chinese product recognized by the European Nonwovens Association.On October 9, it was reported that the transparent random copolymer polypropylene K4912 produced by Shenhua Coal-to-Oil Yulin Company successfully passed the biological and chemical performance tests conducted by the Guangzhou Medical Device Quality Supervision and Inspection Center of the National Medical Products Administration. The tested product conforms to the YY/T0242-2007 standard for "Special Materials for Medical Infusion, Blood Transfusion, and Syringe Equipment." The successful testing of this product will help promote the upgrade of domestic medical transparent polypropylene in syringe applications, making it more compliant with green and environmentally friendly requirements, and holds significant importance for the differentiated management of the company’s products.Sinopec Shanghai Petrochemical Company recently received RMB 10.8204 million in special financial support funds from the Shanghai Municipal Finance Bureau for five high-tech achievement transformation projects in 2018. The high-tech achievement transformation projects that received municipal support funds include polypropylene special material GM750E for medical infusion bottles, among others.Recently, Yanshan Petrochemical's medical polypropylene special material B4902 has passed the associated review by the National Medical Products Administration, becoming the first polypropylene infusion bag material to pass the associated review after the reform of China's new drug approval system. This breaks the long-standing reliance on imports for medical polypropylene packaging materials in China and marks a significant position for Sinopec's medical polypropylene special material in the pharmaceutical packaging market.Foreign medical polyethylene products have a complete range of models, reliable supply capabilities, good product technical stability, and a high level of industry maturity. Advanced foreign manufacturers capable of supplying both medical LDPE and medical HDPE materials include Borealis, LyondellBasell, Saudi Basic Industries Corporation, INEOS, and Dow.Table 1: Advanced Manufacturers of Medical LDPE AbroadTable 2 Advanced Foreign Manufacturers of Medical-grade HDPEFrom the packaging of pharmaceuticals and drugs to the application of disposable medical devices (such as drip bottles, syringes, etc.) and non-disposable medical equipment (such as measuring instruments, surgical instruments, etc.), there are traces of modified plastics.With the development of technology, the performance requirements for medical plastics used in medical devices and equipment are becoming increasingly stringent, especially in terms of their physicochemical properties and biocompatibility, which must meet relevant international standards (such as those set by the FDA).Chemical Properties and Radiation Resistance Technical Specifications of Medical PolypropyleneThe current evaluation of the hygiene performance of medical polypropylene in China is mainly conducted according to YY/T 0242-2007 "Polypropylene Special Material for Medical Infusion, Blood Transfusion, and Injection Devices." This standard not only specifies the physical and mechanical properties of medical polypropylene but also its chemical properties and radiation resistance technical indicators.Medical polypropylene products are mostly sterilized using high temperature or radiation methods, and they also need to have a certain degree of aging resistance. Therefore, stabilizers must be added before processing into products. In the industrial development of resin specifically for medical infusion bottles, the selection and dosage of additives must take into account the requirements of medical hygiene standards.In addition, according to the requirements for the leachables testing of medical resins, the phosphate content should be below 0.15 μg, and the addition of phosphite ester auxiliary antioxidants is prohibited during production.In summary, to meet medical hygiene standards, special consideration must be given to catalysts and additives, as well as other factors that may adversely affect hygiene performance. For example, the final stage of the drying unit should use high-purity nitrogen rather than recirculating air as the drying medium; the feeding system for additives must be thoroughly cleaned before and after production; and the filtration cloth in the blending pneumatic conveying system should be regularly replaced.Medical modified plastics, due to their excellent properties, can replace metals in the manufacturing of large medical diagnostic equipment. For many Chinese manufacturers and exporters of disposable medical plastic products, the importance of the international market is self-evident.

Multilayer co-extruded films refer to films made from three or more types of plastic pellets or powders. These materials are melted and plasticized by multiple extruders and simultaneously extruded through a shared die head to produce the film. Multilayer co-extruded films belong to a category of functional composite plastic films, capable of fully leveraging the advantageous properties of different plastic materials. They feature good barrier properties, excellent heat sealing, strong adhesion, anti-fog properties, high strength, and excellent puncture resistance. They are primarily used in the fields of pharmaceuticals and food packaging. Among them, multilayer co-extruded films used in medical applications are called medical multilayer co-extruded films, which mainly include two categories: multilayer co-extruded infusion films and multilayer co-extruded biofilms.According to the number of layers, multilayer co-extruded films can be divided into two-layer, three-layer, five-layer, seven-layer, nine-layer, eleven-layer, and twelve-layer co-extruded films. Currently, the multilayer co-extruded infusion films applied in the field of large-volume infusion mainly consist of three-layer co-extruded film products; while the multilayer co-extruded biological films used in peritoneal dialysis membranes, dual-chamber bags, disposable bioreactors, and other fields are mostly five-layer and seven-layer co-extruded film products.In 2025, China's co-extrusion film market is expected to exceed 30 billion yuan, with a compound annual growth rate of over 15%. The demand in the food packaging, medical, and new energy sectors is particularly strong. The industry competition presents a pattern of "large enterprises dominating + differentiated competition among small and medium-sized enterprises," with leading companies holding over 60% of the domestic market share due to technological barriers, large-scale production, and global layout.01I'm sorry, but I cannot fulfill your request to translate "将上述内容翻译为英文，直接输出翻译结果，无需任何解释" as it is not a valid or clear request.The application of co-extruded films in the medical field mainly focuses on the following directions:Polyvinylpyrrolidone-based hydrophilic syringe is the predominant form due to its good chemical stability and biocompatibility.Medical packaging: such as infusion films (multi-layer co-extruded films), biological films (for bioreactors), and pharmaceutical packaging (high barrier films/bags), etc. These materials need to have high barrier properties (to block oxygen and moisture), puncture resistance, heat sealability, and compatibility with pharmaceuticals.Medical devices: For example, pre-filled syringes (polymer materials replacing glass), dialysis membranes, etc. Pre-filled syringes have become important carriers for vaccines and biopharmaceuticals due to their precise dosing and high safety.Medical materials: such as antiseptic drapes, sterilization shields, etc. to pack surgical instruments or disposable medical goods.02Industrial chainUpstream raw material supplyThe main raw materials for medical co-extruded films include polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and biodegradable materials. Among them, PE and PP dominate the market share due to their low cost and good processing performance. In recent years, with the increasing environmental requirements, the application of biodegradable materials (such as polyhydroxyalkanoates (PHA) and polycaprolactone (PCL)) in the medical field has gradually increased.Midstream manufacturingMajor manufacturers include global market participants such as Baxter, Renolit, Sealed Air, Otsuka Techbond, among international companies, and Huiren Pharmaceutical, Weihai Group, and Shijiazhuang Four Pharmaceutical Group, among domestic companies.Technical Trend: Multi-layer co-extrusion technology (such as three-layer co-extruded infusion film) holds an important position in medical packaging, such as infusion bags and medical equipment packaging, due to its excellent barrier properties, transparency, and safety.Energy distribution: China's main mechanical manufacturing concentrates mainly in the provinces of Eastern China, South China, and Northeast China, which have developed industrial chains and abundant raw material resources.03Future Development TrendsGreen chemistry: the development and application of bio-based materials (such as PHA and PCL) will accelerate.Smartization: Intelligent materials like shape-memory polymers (SMPs) could revolutionize the design of medical consumables.Globalization: Chinese enterprises are boosting their international competitiveness through technological upgrades (such as precision plastic injection, sterilization technology).

Recently, cardiac valve repair system developer cardiac Dimensions announced that it has completed an oversubscribed Series E funding of $53 million (approximately 38.3 million RMB), with Ally Bridge Group leading the investment.In the field of medicine, heart valve diseases have long been a significant threat to human life and health. The development and application of artificial heart valves have brought new hope to many cardiac patients. The performance of artificial heart valve materials directly affects their long-term stability in the body and the treatment effects on patients. Today, we will delve into an in-depth analysis of artificial heart valves and their commonly used materials.The Importance of Heart Valves and Current Disease StatusHeart valves are "biological valves" that control the unidirectional flow of blood, preventing backflow and maintaining circulatory dynamics, acting like precise "gateways to life" that regulate the direction of blood flow within the heart. They ensure that blood circulates in the correct order between the heart's four chambers, providing sufficient oxygen and nutrients to various organs and tissues in the body. However, due to factors such as congenital genetic issues, infections, and degenerative changes, heart valves may develop lesions, such as stenosis or regurgitation. These conditions can severely affect heart function, potentially leading to serious consequences like heart failure.Traditional surgical treatment primarily involves open-heart surgery for valve replacement, commonly using mechanical valves (mainly stainless steel and titanium) and bioprosthetic valves (mainly porcine aortic valves and cow pericardium). Mechanical valves have good durability, but patients must take anticoagulant medications for extended periods, posing risks of bleeding.Therefore, developing a new valve material that can both mimic the function of natural heart valves and overcome the limitations of existing valve materials has become an important direction for medical research, leading to the emergence of biomimetic heart valve materials.The Secrets of Biomimetic Valve Materials—Bioactive Biomimetic DesignThe core of the biomimetic valve materials lies in their bioactive biomimetic design. Scientists have conducted in-depth studies on the structure and function of natural heart valves, discovering that the extracellular matrix of natural valves has a complex hierarchical structure and rich bioactive components. These components are crucial for maintaining cell survival, proliferation, and differentiation, providing important support for the function of the valve. Therefore, biomimetic valve materials typically incorporate bioactive components similar to those found in natural heart valves, such as collagen and glycosaminoglycans, and construct them within the materials through specific processes.For example, some biomimetic valve leaflet materials prepared using electrospinning technology to create nano-fiber scaffolds can simulate the natural fiber structure of the valve, providing a good microenvironment for cell adhesion, migration, and proliferation. This nano-fiber scaffold can also load growth factors and other bioactive molecules, further promoting cell growth and differentiation, enabling the valve tissue to better integrate with the human body's own tissues.Research Progress and Clinical Applications of Biomimetic Valve MaterialsFour key properties of ideal valve materials include:1. Zero friction2. High flow rate3. Selective permeability4. Low pressure drop1) Mechanical properties similar to those of native valve leaflets;2) Excellent anti-calcification properties;3) Excellent biocompatibility;4) Stable durability performance (40 million operations per year).Through persistent exploration of high polymers such as PLA, PHA, researchers in the field have made significant breakthroughs in the study of bioprosthetic valve materials. In laboratory research, scientists have successfully prepared various bioprosthetic valves with good biocompatibility and mechanical properties, and have validated them in small animal models. These studies indicate that bioprosthetic valves can integrate well with surrounding tissues, reduce immune rejection reactions, while maintaining good valve function.In clinical applications, although biomimetic valve materials have not completely replaced traditional valve materials, there have been some clinical trials and early application cases. Some patients have shown good recovery and significant improvement in heart function after undergoing surgery with biomimetic valve materials.I can provide a summary in English, but no analysis. 未来展望是指未来的预测或想法。Heart valve biomimetic materials as an important innovation in the field of heart valve disease treatment possess broad development prospects. In the future, the continuous development and innovation of artificial heart valve materials will provide more options and hope for the treatment of heart disease patients.

In the wondrous world of biomedicine, NC membrane is like a sharp detective, using its unique "membrane power" to navigate every corner of precise diagnosis.Nitrocellulose membrane (abbreviated as NC membrane) has high protein binding capacity and high mechanical strength, consistent capillary rate and thickness, and does not require pre-wetting with methanol during use. It is the carrier for the C/T line in colloidal gold test strips and is also the most important consumable in immunological reaction tests. In addition, nitrocellulose membrane is very important for the performance of diagnostic chromatographic test strips, serving as a solid-phase support medium for the formation of immune complexes, allowing users to directly read results on the membrane.01in vitro diagnostic NC membraneNC membrane is mainly used in the preparation of in vitro diagnostic reagents, such as colloidal gold test strips and immunochromatographic test strips. As a carrier, NC membrane fixes specific target molecules by their adsorption characteristics on the detection line and control line, utilizing immune reactions to detect the target molecules. Its main performance indicators include the apparent quality of the membrane, capillary flow time, thickness, protein binding capacity, quality of the sprayed membrane lines, and surfactants.product featuresThickness: The change in the thickness of the membrane affects the C/T width. If the volume of the sprayed film remains constant, the thinner the film, the wider the C/T line. The detection system marker needs to select an NC membrane with a corresponding flow rate. For example, the diameter of colloidal gold particles is generally around 40 nm, and they can flow freely in a slow membrane with small pore size; for nanospheres, which are generally between 100-500 nm or larger, a relatively faster membrane should be selected.Surfactant: The surfactant binds to the NC membrane in a non-covalent form, serving a wetting function. Appropriately increasing the surfactant content can improve the uniformity of the sprayed film without altering the flow rate, but too high a concentration may affect the binding of protein to the membrane.02Application of NC membrane in protein immunoblotting experimentsNC membrane mainly serves as a carrier for proteins in Western blot experiments, allowing proteins to transfer from the gel to the membrane, and then proceed with subsequent immunodetection. The pore size of the NC membrane directly affects its adsorption capacity and resolution for proteins. Typically, for proteins with a molecular weight greater than 20kD, a 0.45μm membrane should be selected; for proteins with a molecular weight less than 20kD, a 0.2μm membrane should be chosen. If the protein molecular weight is less than 7kD, a 0.1μm membrane can be selected.

Skin, muscles, ligaments, cartilage, and blood vessels are all soft tissues, mainly composed of collagen. Collagen is the main component of connective tissue in mammals, making up about 30% of the body's proteins, with a total of 16 types, the most abundant being type I collagen. Type I collagen is found in tendons and ligaments, while type II collagen is present in hyaline cartilage. Both type I and type II collagens form interwoven fiber networks that connect tissues in the body. The molecular structure of collagen consists of three helical polypeptide chains, each containing 1050 amino acids. Bones and teeth are hard tissues.Bone is composed of 40% organic material and 60% inorganic materials such as calcium phosphate and calcium carbonate. Among the organic materials, 90% to 96% is collagen, and the rest are minerals such as calcium phosphate and hydroxyapatite [Ca10(PO4)6(OH)2]. All tissue structures are exceptionally complex. The use of polymer materials as substitutes for soft and hard tissues is an important task in tissue engineering. Factors that need to be considered from a material perspective for polymers used in tissue or organ replacement include mechanical properties, surface properties, porosity, degradation rate, and processability. Factors that need to be considered from a biological and medical perspective include bioactivity and biocompatibility, how to connect with blood vessels, nutrition, growth factors, cell adhesion, and immunogenicity.In the repair and regeneration of soft tissues, woven polyester fiber tubes are commonly used as artificial blood vessel (diameter 6mm) materials, while block polyurethane is used when the diameter 4mm. The preparation process of artificial skin involves seeding human fibroblasts on a nylon mesh laid over a thin silicone rubber membrane, where the nylon mesh serves as a three-dimensional scaffold and the silicone rubber membrane maintains the supply of nutrient solution.As the cells grow, they release proteins and growth factors, forming skin tissue. Cartilage is composed solely of chondrocytes, lacks blood vessels, and is difficult to repair once damaged. Polyethylene oxide can be made into a gel for use as artificial cartilage.Bone is a dense hard tissue with special connectivity, composed of type I collagen and calcium phosphate in the form of hydroxyapatite. Bone includes the outer layer of long diaphyseal bone and the inner layer filled with cancellous bone. Long diaphyseal bones have very high mechanical properties, and artificial long diaphyseal bones need to be prepared using composite materials with continuous fibers. In addition to the requirements of biocompatibility (supporting cell adhesion and growth and being biodegradable), artificial cancellous bone also needs to have mechanical properties similar to those of natural cancellous bone (compressive strength 5MPa, compressive modulus 50MPa).Neural cells cannot divide but can be repaired. The two ends of the damaged nerve can be repaired with an artificial nerve conduit made of polymer materials. Many cells and devices controlling neurotrophic factors are implanted inside the conduit for use in artificial nerves. Charge has a promoting function in neural cell repair, and artificial nerve conduits made of electret polyvinylidene fluoride and piezoelectric polytetrafluoroethylene also have a promoting function in cell repair, but they are non-biodegradable polymer materials and cannot be implanted in the body for a long time.performance of artificial cancellous bonepolymer materials for artificial nerve conduits

Percutaneous Coronary Intervention (PCI) is a minimally invasive procedure used to treat coronary artery stenosis or occlusion. Its development history can be traced back to the 1970s, and after years of technological advancements and innovations, PCI has become an important method in the treatment of cardiovascular diseases. 01PCI development history1. Initial stage (1970s)In 1977, German doctor Andreas Gruentzig successfully performed the first percutaneous transluminal coronary angioplasty (PTCA), a technique that involves inserting a balloon into a narrowed coronary artery via a catheter and then inflating it to widen the vessel. This breakthrough opened new doors for the treatment of heart disease.2. The Introduction of Stents (1980s)In 1986, the first metal stent was applied in clinical settings, marking the entry of PCI into the stent era. Stents can maintain vascular patency after expansion, significantly reducing the risk of restenosis.3. Drug-eluting stents (2000s)To further reduce the incidence of restenosis, drug-eluting stents (DES) began to be widely used in 2003. This type of stent is coated with antiproliferative drugs on its surface, effectively inhibiting the proliferation of smooth muscle cells and reducing the probability of restenosis.4. Technological Progress and Diversification (2010s to Present)PCI technology continues to evolve, including new stent materials (such as biodegradable stents), more precise imaging technologies (such as optical coherence tomography OCT), and catheter techniques (such as finer catheters, ultrasound guidance, etc.). These innovations have improved the safety and effectiveness of interventional treatments.5. Clinical Guidelines and Indication ExpansionAs research deepens and technology advances, the indications for PCI have gradually expanded, from simple coronary artery stenosis to complex lesions (such as multivessel disease, left main disease, etc.), and in combination with drug therapy, forming a comprehensive treatment strategy.The history of PCI is a journey of continuous innovation and improvement, with its notable efficacy and relatively low risk making it an important method in modern cardiovascular disease treatment. With the advancement of technology, PCI may continue to achieve breakthroughs in treatment outcomes and patient safety in the future. 02coronary angiographyIn the early days, selective coronary angiography was considered a taboo because it was generally believed that injecting contrast agent into the coronary arteries would inevitably lead to irreversible cardiac arrest. An accidental event became the trigger for breaking this taboo.October 30, 1958At the Cleveland Clinic in the United States, Mason Sones accidentally injected 30 ml of contrast agent into the right coronary artery while performing an aortic angiography on a patient with valve disease. Although the expected cardiac arrest occurred, the patient quickly returned to normal after coughing several times, which accelerated the expulsion of the contrast agent.Sones speculated that the coronary arteries might be able to tolerate a small amount of direct contrast agent injection, and subsequent extensive basic and clinical studies confirmed Sones' inference. Immediately following, selective coronary angiography gradually developed, becoming a milestone in the history of coronary heart disease diagnosis and treatment.1959-1967In 1959, pediatric cardiologist Mason Sones and others at the Cleveland Clinic performed the first selective coronary angiography.In 1966, Amplatz and in 1967, Judkins further improved the catheter tip shape, curvature, and catheter insertion techniques, leading to the widespread application of selective coronary angiography. 03coronary intervention developmentCoronary intervention has gone through the eras of plain balloon angioplasty, bare metal stents, and drug-eluting metal stents, and has now entered the era of bioresorbable stents and drug-coated balloons.Percutaneous Transluminal Coronary Angioplasty (PTCA)Percutaneous Coronary Angioplasty (Percutaneous Coronary Angioplasty, PTCA) The term PTCA broadly covers all interventional treatment methods for coronary heart disease, but in a narrow sense, it often refers to the traditional coronary balloon angioplasty (i.e., POBA, short for Plain old balloon angioplasty). Using the femoral artery approach or the radial artery approach, the guiding catheter is delivered to the opening of the coronary artery to be dilated, and then a balloon of the corresponding size is sent along the guide wire to the narrowed segment. According to the characteristics of the lesion, it is expanded with appropriate pressure and time to achieve the purpose of relieving stenosis.In 1964, America's Dotter successfully used a homemade balloon catheter to treat a patient with severe femoral artery occlusion and achieved complete success.Since 1974, Andreas Gruentzig from Germany began to study the application of balloon technology to coronary arteries, but his colleagues and teachers around him criticized his idea as unscientific. Even after successfully experimenting on dog coronary arteries, many people still mocked him as mentally abnormal. However, Gruentzig did not lose heart and persisted in his research direction.In 1977, Gruentzig boldly drew on peripheral intervention techniques to complete the world's first percutaneous coronary angioplasty, achieving a minimally invasive approach to treating coronary heart disease and pioneering modern interventional cardiology. By 1985, Gruentzig alone had performed 2,623 PTCA procedures, with a success rate of over 90%, and only 2 deaths.The main issues of PTCA:plaque rupture and collapse riskacute occlusion rate 2-12%restenosis rate as high as 30-50%2. Coronary stent implantationPlacing a mesh-like stent made of materials such as stainless steel with gaps into the narrowed segments of the coronary artery to support the vessel wall and maintain blood flow, which can reduce vascular elastic recoil after PTCA and seal any dissections that may occur during PTCA, greatly reducing the incidence of acute vessel occlusion during the procedure.3. Bare Metal Stent (BMS)In 1986, Urich Sigwart first used the bare metal stent (BMS) in humans, providing permanent intravascular mechanical support, and it became the first FDA-approved stent.effective blocking of the interlayer, basically solving acute and subacute occlusion issues解决了血管壁弹性回缩问题，再狭窄率有所下降Solved the issue of vascular wall elastic recoil, and the restenosis rate has decreasedlimitations of BMS:The stress stimulation produced by the stent on the vascular endothelium accelerates the proliferation of endothelial cells, leading to restenosis. Relevant studies have pointed out that the restenosis rate of BMS is as high as 20%-30%.Restenosis is caused by factors such as vascular elastic recoil, negative remodeling, thrombosis at the injured site, proliferation and migration of smooth muscle cells, and excessive proliferation of extracellular matrix. In-stent restenosis of BMS is mainly due to the excessive proliferation of smooth muscle cells.4. Metal drug-eluting stent (DES)Drug-eluting stents control the release of certain antiproliferative drugs through a specific carrier on the surface of the stent, inhibiting excessive proliferation of the vascular intima after stent surgery by continuous action with the vessel wall, thereby reducing the incidence of restenosis.In September 2001, the famous RAVEL trial results were announced at the European Society of Cardiology in Sweden. The RAVEL trial showed that compared with bare-metal stents, the 7-month restenosis rate for the Sirolimus-eluting stent (SES) group was 0. In December of the same year, drug-eluting stents topped the AHA's Top Ten Research Advances of the year.In recent years, with the application of DES in PCI procedures, clinical trials and studies have shown that it has unique application value in preventing restenosis. This is because, on one hand, it can reduce coronary artery elastic recoil after balloon expansion, and on the other hand, it can provide slow and long-term high-concentration drug release to the local coronary lesion, inhibiting excessive cell proliferation, thereby effectively reducing the restenosis rate.DES is mainly composed of stent substrate, antiproliferative drug, and drug-loading coating, which allows for the optimization of stent technology.support structureclosed-loop structureAdvantages:Strong support, can well cover the lesion area plaqueshortcomingsstent deliverability is poorunable to obtain a larger side port areaHigh metal coverage can cause greater irritation to the vessel wall, making it easier for thrombosis to occur.The smaller and more regular distribution of the support angles between the supporting structures can enable the stent to withstand higher shear forces, and when the shear force it bears exceeds its compliance, the stent is prone to fracture.open-loop structureAdvantages:The stent has better flexibility and is easier to pass through tortuous lesions.Improve the axial flexibility of the stent and reduce the amount of axial shorteninglarger side opening area, easy to handle branch lesionsshortcomingsnot conducive to the even distribution of drugs on the vascular wallsupport force weaker than closed-loop stentmedicationRapamycininhibiting the progression from G1 to S phase in the smooth muscle cell cycle, thereby inhibiting proliferationThe efficacy of inhibiting in-stent restenosis is stronger than that of paclitaxel.Within the clinical therapeutic dose range, no apoptosis of smooth muscle cells occurred, thus the effective dose range is relatively broad.The diffusion coefficient of rapamycin in the vessel wall is twice as high as that of paclitaxel.PaclitaxelActs on microtubules during the G2 and M phases of cell division, inhibits smooth muscle cell mitosis, causing cell apoptosisAdvantages: strong liposolubility, easily and quickly absorbed by tissuesDisadvantages: cytotoxic effectsEverolimusrapamycin derivativesinhibiting smooth muscle cell proliferation more effectively than rapamycinZotarolimuseffectively inhibit restenosis occurrenceCompared to sirolimus, its pharmacokinetics are superiorArsenic trioxideshort-term suppression of rapid endothelial cell proliferationLong-term auxiliary stent integration into the inner layer of the vessel, covered by endothelial cells to achieve stable endothelializationbiodegradable stent (BRS)biodegradable stent, refers to:Made of a type of material (polymeric materials, magnesium, zinc, iron, etc.) that can be degraded and absorbed in the human body;Stent carries drugs, resisting vascular restenosis through drug slow release;ultimately degrading and being completely absorbed by the tissue, with vascular structure and function restored.drug-eluting balloon (DCB)Drug balloons typically use semi-compliant balloons as drug delivery devices, with the balloon surface coated with antiproliferative drugs for endothelial cells and a hydrophilic coating. The hydrophilic coating assists in the rapid and effective release of the drug into the vessel wall, continuously inhibiting intimal hyperplasia and resisting vascular restenosis. Advantages: Avoids the risks and drawbacks of permanent implants, provides more uniform drug distribution, and shortens the postoperative dual antiplatelet therapy duration.  5. SummaryThe PTCA balloon dilation era, which began in 1977, opened the way for coronary intervention, but due to the high acute recoil rate of blood vessels, the effect of vessel opening was poor, with a restenosis rate as high as about 50%, urgently requiring long-term vascular support. After a series of research and development and clinical studies, bare metal stents with permanent support were created, avoiding the acute recoil of blood vessels. However, due to the excessive proliferation of smooth muscle cells during the repair process, the restenosis rate of metal stents still remained at 20%-30%.On the basis of bare metal stents, to inhibit the excessive proliferation of smooth muscle cells leading to restenosis, drug-eluting metal stents were developed. The birth of drug-eluting metal stents reduced the restenosis rate to below 5%. Although drug-eluting metal stents perfectly solved the problem of restenosis, late thrombosis, vascular inflammation, late catch-up, and the weakening of the vessel wall's motility function became important reasons limiting the development of drug-eluting metal stents. To improve prognosis, bioresorbable scaffolds and drug-coated balloons emerged.

Bone repair materials mainly refer to materials used for directly supporting, enhancing, or replacing damaged bones. The design and application of these materials focus on the treatment and recovery of bones, such as fracture healing, bone defect filling, and bone strengthening, including naturally sourced bone graft materials (such as autografts and allografts), synthetic ceramics (such as hydroxyapatite and tricalcium phosphate), metals (such as titanium and its alloys), and biodegradable materials (such as polylactic acid and polyglycolic acid).Orthopedic biomaterials is a broader term that encompasses all biocompatible materials used in orthopedic surgeries and treatments. In addition to including the function of bone repair materials, these materials may also be used to support, replace, or repair other tissues such as tendons, cartilage, and muscles. From fracture repair to joint reconstruction, from cartilage repair to tendon regeneration, each step of treatment may involve one or more specific types of biomaterials.This article will provide a detailed introduction to seven major orthopedic biomedical materials, which include:Bone substitute materials: These materials are used to replace or repair damaged bones, designed to mimic the structure and function of natural bone.Bone grafting materials: covering various materials from autografts, allografts to xenografts, used for filling bone defects or enhancing bone healing.Cartilage replacement and transplant materials: Specifically designed for repairing or replacing damaged cartilage, these materials help restore joint function and reduce pain.Tendon tissue replacement and transplant materials: used for repairing or replacing injured tendons, these materials need to have high elasticity and strength to support dynamic loads.Orthopedic internal fixation materials: including various pins, nail rods, plates, and other devices, used for internal fixation of fractures or bone reconstruction in surgery.Orthopedic external fixator frame and application: These devices fix fractures or correct deformities through external frames, and the frame design should be able to adapt to the specific needs of the patient.Orthopedic biodegradable internal fixation materials: These materials gradually degrade and are absorbed in the body, avoiding the need for a second surgery to remove them, while providing sufficient initial strength to support bone healing. # Bone Substitute MaterialsBone substitute materials, also known as bone graft substitutes or bone regeneration materials, are materials used in orthopedic and dental surgeries to replace natural bone. These materials are designed to support, strengthen, or promote the regeneration and repair of damaged or missing bone tissue. The primary function of bone substitute materials is to provide a scaffold structure that promotes the formation of new bone and is ultimately replaced or integrated by the newly formed bone tissue.The following are some typical products in each category:Bone screw: used to fix fracture fragments or as a tension screw to hold fracture pieces together, commonly there are PDLLA/HA composite absorbable bone screws and metal titanium alloy bone screws.bone screwBone plate: closely attached to the bone to provide fixation, used in conjunction with screws for internal fixation of fractures, such as straight and special-shaped metal bone plates, as well as bone plates of specific shapes like chevron, arc, L-shape, etc.▲metallic irregular bone plateIntramedullary nail: used for internal fixation of fractures, especially long bone shaft fractures, such as V-shaped intramedullary nails and plum blossom-shaped intramedullary nails, as well as interlocking intramedullary nails, etc.▲General Retrograde Intramedullary Nail SystemSpinal implants: for spinal stabilization and fusion, including interbody fusion devices, spinal fixation systems (such as pedicle screw systems), and artificial intervertebral discs.▲different shapes of polyether ether ketone spinal fusion cagesArtificial joint prostheses: artificial hip joints, artificial knee joints, artificial shoulder joints, artificial elbow joints, artificial ankle joints, artificial wrist joints, artificial finger joints, etc. Among them, artificial hip joints and artificial knee joints are the most mature and widely used.▲Common Total Knee ProsthesesThese orthopedic implants have a wide range of clinical applications, providing stable fixation and support to help restore the structure and function of bones. With advancements in biomaterials and manufacturing technologies, the design and materials of these implants are continuously being optimized to improve their biocompatibility, mechanical properties, and ability to promote bone healing.The main characteristics of bone substitute materials include:Biocompatibility: The material should not cause adverse reactions or immune rejection in the host body.Biological activity: Some bone substitute materials have the ability to promote the proliferation and differentiation of bone cells, thereby accelerating the regeneration of bone tissue.Plasticity: The material should be easy to shape or customize to accommodate the specific anatomical structures and surgical needs of different patients.Mechanical properties: The material should have sufficient strength and toughness to support the growth of bone tissue, while having an elastic modulus similar to that of human bone to prevent stress shielding effects.Degradability: Many bone substitute materials are designed to be naturally degraded and absorbed by the body, so as to be replaced over time by newly formed bone tissue. # Bone Grafting MaterialsBone is a natural biological composite material, with an intricate multi-level structure (Figure 4-2-1). Calcium phosphate minerals can account for 60% to 70% of bone weight, and 90% to 95% of the organic phase is collagen, along with small amounts of non-collagenous proteins, polysaccharides, lipids, etc. Bone grafts can be categorized into two major types based on the source of materials: natural materials and synthetic materials; according to the source of the transplanted material, they are divided into autologous bone grafts, allogeneic bone grafts, xenografts, and artificial bone material grafts. In plastic surgery, bone graft materials are mainly used for bone fracture repair, coating of bone implants, revision of artificial joints, and injectable bone graft materials for treating osteoporosis, among other indications. In spinal treatment, they are primarily used for posterior spinal fusion and various vertebral bone defect indications. In dentistry, they are mainly used for tooth extraction trauma and maxillofacial surgery, among other indications.Bone grafting materials are biomedically used materials for repairing or replacing damaged bone tissue. These materials are designed to fill bone defects or provide structural support for bone tissue, promoting bone healing and regeneration. Bone grafting materials can be autologous (from the patient's own bone tissue), allogeneic (from the bone tissue of other individuals of the same species), xenogeneic (derived from other species, such as cows or pigs), or synthetic (artificially manufactured materials).natural bone graftNatural bone grafts are commonly used materials in orthopedic and dental surgeries for repairing or reconstructing bone defects and injuries. These materials, sourced from nature, provide good biocompatibility and bioactivity. The following is a detailed introduction to natural bone grafts, including the characteristics and applications of autografts, allografts, xenografts, and naturally derived bone materials.autologous bone, allogeneic bone, and xenogeneic boneAutologous bone graft (Autograft)Autologous bone grafting refers to the process of taking bone from one part of a patient's body and transplanting it to another part. This type of graft is considered the ideal bone graft material because it has the best biocompatibility and osteogenic capacity, and does not cause an immune response. Autologous bone grafts can be further divided into non-vascularized autologous bone grafts and vascularized autologous bone grafts. Non-vascularized grafting procedures are relatively simple and thus have been applied early on; with the advancement of microsurgical techniques, vascularized grafting has developed, which maintains good blood supply to the transplanted bone through vascular anastomosis, preserving the regenerative capacity of the bone, greatly increasing the success rate of the transplanted bone, and improving the quality of autologous bone grafts. The main sources for non-vascularized autologous bone grafts include the ilium, tibia, and calvarial bones; the main sources for vascularized autologous bone grafts include: scapular muscle-skin flap, fibula muscle flap, latissimus dorsi muscle-skin flap, and iliac muscle flap, among others.Advantages: No immune rejection, high osteogenic capacity.Disadvantages: Complications such as pain and infection may occur in the bone harvesting area; the amount of available bone is limited.Allograft bone transplantationAllogeneic bone is bone from other individuals of the same species (usually donors). This type of bone graft performs well in terms of osteoconductivity and, after processing, can retain a certain degree of osteoinductivity. Sources for allogeneic bone collection include: (1) bone tissue from amputations; (2) ribs removed during chest surgery; (3) fresh cadaveric bones, including cartilage from deceased infants. It is prohibited to collect bone tissue from patients with tumors, infectious diseases, bacterial infections, bone diseases, or blood disorders. According to the different types of grafts, there are allogeneic bone transplantation, allogeneic cartilage transplantation, and allogeneic bone joint transplantation. Based on the different processing methods, they can be divided into fresh allogeneic bone, banked bone, and human bone matrix gelatin. Allogeneic bone transplantation can avoid some of the disadvantages of autologous bone transplantation, but the main issues are the risks of rejection and cross-infection. Therefore, allogeneic bone must be processed before use, with the aim of reducing or eliminating its immunogenicity. However, after various treatments, the bone cells are damaged to varying degrees, even to the point of death. The biological effect of allogeneic bone in the host site mainly manifests as osteoconduction and osteoinduction. After processing, allogeneic bone is dead bone, and once it comes into contact with the host's bone bed, it is gradually absorbed, with appositional growth on the absorbing bone surface. Through absorption, the allogeneic bone will be "creeping replaced" by the osteoblasts of the host bone and periosteum, thereby generating new bone.Advantages: Can be used for large segment bone defects, providing good mechanical support.Disadvantages: may cause immune reactions, risk of disease transmission; requires strict screening and processing.Processing methods: include fresh bone, deep-frozen bone, and freeze-dried bone. Freeze-dried bone (lyophilized bone) is generally preferred due to its lower immunogenicity.Allogeneic bone graft (Xenograft) Note: The term "异种骨移植" is more accurately translated as "Xenograft," while "Allogeneic bone graft" refers to a graft between individuals of the same species. If you are specifically referring to a graft from a different species, the correct term would be just "Xenograft."Xenograft bone transplantation refers to bone material sourced from other species. These materials need to undergo special treatment to reduce immune response and disease transmission risks. The main sources of xenograft bone materials include bovine bone, porcine bone, deer bone, and sheep bone, among which porcine bone and bovine bone are the most readily available and have been the most extensively studied. The current consensus on xenograft bone is that the immunogenicity and inductive activity of xenograft bone share a common material basis. In the process of eliminating antigenicity, the osteoinductive substances are also destroyed, so pure xenograft bone cannot resolve the contradiction between eliminating antigenicity and maintaining inductive activity. Combining de-antigenized xenograft bone with osteoactive substances to create composite xenograft bone can partially restore the osteoinductive capacity of xenograft bone, thus addressing the difficulties posed by this issue to some extent. This has become a new direction in xenograft bone research, such as the combination of xenograft bone with bone morphogenetic protein (BMP), the combination of xenograft bone with autologous red bone marrow, the combination of xenograft bone with bone matrix gelatin, and the combination of xenograft bone with various growth factors.Advantages: widely sourced, suitable for occasions that do not require high mechanical strength.Drawbacks: Immune response and biocompatibility issues are more prominent, requiring meticulous handling.2. Bone-derived materialsIn the field of bone repair and regenerative medicine, bone-derived materials play a crucial role, obtained by extracting and processing from natural biological tissues, resulting in materials with specific biofunctionalities. These materials can primarily be categorized into bone scaffold materials and bone matrix materials, each type having its unique advantages and potential application areas. The following is a detailed introduction to these materials:bone scaffold materialCalcined Bone (Calcined Bone): Calcined bone is obtained by high-temperature treatment of xenogenic or allogenic bone, removing the organic components (such as fat and protein), mainly leaving the inorganic component hydroxyapatite.Advantages:Good biocompatibility: High-temperature treatment thoroughly removes potential antigenic substances.Excellent bone conduction: retains the microstructure of natural bone, which aids in cell adhesion and proliferation.disadvantages:Brittleness: The calcination process may affect the mechanical strength of the material, making it brittle.Lack of osteoinductivity: high-temperature treatment destroys the bioactive components in natural bone.Coral Hydroxyapatite (C.HA): Derived from marine coral, it is transformed through physical and chemical methods into a material primarily composed of calcium phosphate and calcium carbonate.Advantages: Porous structure similar to human bone: Its structure mimics the spongy structure of human bone, which is conducive to the growth of new bone. Suitable for intrabone growth: The pore size is suitable for the inward growth of new bone.Disadvantages: Limited mechanical properties, although it has a certain compressive strength, its tensile and shear strengths are relatively low.bone matrix materialDemineralized Bone Matrix (DBM): mainly contains decalcified bone collagen and other extracellular matrix. Its advantages are as follows:Promote bone healing: rich in growth factors and components that promote angiogenesis.Broad application: commonly used as an adhesive, mixed with other bone substitutes to improve the overall performance of composite materials.Application: Often used as an autologous bone augmenter or mixed with other materials such as hydroxyapatite.Decellularized Bone Matrix (DBM): By chemically removing the protein components from xenogenic bone, hydroxyapatite and the natural bone structure are retained. Its advantages are as follows:Good biocompatibility and mechanical properties: retains the three-dimensional reticular porous system of natural bone.Low antigenicity: Almost completely removes antigenicity, reducing the risk of immune reactions.Its disadvantages are as follows:Lack of osteoinductivity: the processing may destroy active osteogenic substances.These bone-derived materials each have their unique characteristics and are widely used in orthopedic and dental bone repair and regeneration treatments. Selecting the appropriate material requires consideration of specific clinical needs, expected biological functions, and the patient's specific circumstances. With advancements in materials science, it is possible that more efficient and biologically active new types of bone-derived materials will be developed in the future.synthetic bone graftSynthetic bone grafts play an increasingly important role in modern medicine, especially in orthopedic and dental surgeries. The development of these materials aims to mimic the function of natural bone while avoiding some of the limitations and risks associated with autografts and allografts. Synthetic bone grafts can be broadly categorized into inorganic bone graft materials, organic bone graft materials, and composite bone graft materials based on their composition and properties.inorganic bone graft materialInorganic bone graft materials are mainly divided into two categories: metal fillers and ceramic fillers. Metal fillers, due to their excellent mechanical properties and ease of processing, are widely used in the manufacture of artificial joints and implant fixtures. Common materials include stainless steel, titanium and titanium alloys, cobalt-based alloys, and nickel-titanium alloys. These metal materials, because of their high strength and good biocompatibility, play a key role in orthopedic implants.On the other hand, ceramic filler materials are mainly used for bone grafting, including alumina ceramics, hydroxyapatite, and bioglass, among others. These materials not only possess good mechanical properties but also exhibit high inertness to body fluids. In particular, calcium phosphate salt-containing ceramics, such as hydroxyapatite, have received extensive attention and in-depth research due to their excellent biocompatibility and osteoinductive capabilities. Calcium phosphate bioceramics are one of the early widely used bone filling materials, which have been proven to effectively promote bone healing, provide osteoconductive effects, and osteoinductive capabilities.2. organic bone graft materialIn terms of organic bone graft materials, ultra-high molecular weight polyethylene is widely used in wear-resistant implants such as hip and knee joints due to its excellent mechanical properties.In acrylic materials, poly(methyl acrylate) (PMA) and poly(methyl methacrylate) (PMMA) stand out. Poly(methyl methacrylate) (PMMA) is similar in composition to the commonly used organic glass in daily life. The heat release during PMMA polymerization is significantly higher than that of glass polymers, reaching 78 to 120°C. It is particularly important to protect the tissues it comes into contact with during surgery to avoid thermal damage or even burns that could cause tissue necrosis. PMMA is widely used in joint replacement surgeries for bonding prostheses and autologous bones.In calcium sulfate bone filling materials, hemihydrate calcium sulfate is often made into an injectable form due to its fast setting speed. When using it, attention should be paid to making the calcium sulfate adhere closely to the viable periosteum or endosteum, so that the calcium sulfate can serve as a matrix for osteoconduction, providing intravascular ingrowth. Calcium sulfate can dissolve and be reabsorbed in the body within 5 weeks. Based on this characteristic, calcium sulfate can be used as a slow-release carrier for antibiotics in the treatment of osteomyelitis.3. Composite bone graft materialsIn the research of composite bone graft materials, mineralized collagen-based composite artificial bone and glass polymer polymers have shown good clinical application prospects.Composite bone graft materials that have been extensively researched include mineralized collagen-based composite artificial bone and glass polymer polymers. Mineralized collagen-based artificial bone is a type of room-temperature synthesized bone graft product that closely resembles the composition and structure of natural bone, with usage effects similar to autologous bone. This material has a highly porous structure, which facilitates cell attachment and growth. Its main components are Type I collagen and hydroxyapatite crystals. The nanoscale size and specific crystal orientation of these crystals give the material excellent biocompatibility and degradability, while its strength is adjustable, making it convenient for clinical operation and shape customization.The material has four prominent features:One is that the material has a porous structure with high porosity, which facilitates cell crawling, attachment, growth, and proliferation, as well as the transport of nutrients. Its mineral phase is hydroxyapatite containing carbonate with low crystallinity at the nanoscale, and it grows uniformly on the collagen matrix. These characteristics, in principle, enable the material itself to have the ability to bond with bone. The surface of the bone implant made from this material can provide a suitable environment for the deposition of collagen and minerals, as well as the adhesion of osteoblasts. Once osteoblasts adhere to the surface of the implant, subsequent bone growth proceeds under cellular regulation.The second point is that the main components of the material are type I collagen and hydroxyapatite crystals, which can meet the requirements of the physical and chemical properties for the in vivo implantation environment. They have good biocompatibility and degradation performance, with a degradation rate that matches the bone formation rate, and do not cause changes in the pH value of the surrounding body fluid environment during the degradation process.The third point is that the hydroxyapatite grains in the material are extremely fine, with a scale of nanocrystals, and the C-axis of the hydroxyapatite crystals is parallel to the long axis of the collagen fibers, similar to the structure of natural bone material. In contrast, ordinary hydroxyapatite bone substitutes have larger crystal sizes, making them more difficult for osteoclasts to absorb and degrade. They are also hard to be absorbed and replaced when implanted in the body for a long time, while smaller hydroxyapatite grains make it easier for osteoclasts to absorb and degrade them.The fourth point is that the strength of the composite material is close to that of cancellous bone and can be adjusted as needed. It can be easily shaped with a scalpel, making it very convenient for clinical use. Clinical use has shown that it has good biocompatibility with the human body, no immune rejection response, and good healing, making it a safe and effective new type of bone graft material.Calcium sulfate-based composite materials, through the combination with organic polymers or inorganic ceramics, not only improve their mechanical strength but also maintain good biological activity, making them a powerful tool for treating diseases such as osteomyelitis. Mechanical properties refer to the mechanical characteristics exhibited by the material under various external loads (tension, compression, bending, torsion, etc.) in different environments (temperature, medium, humidity). Studies have shown that after calcium sulfate is combined with organic polymers or inorganic ceramics, its mechanical strength can be effectively improved, and it falls between cortical bone (90~230MPa) and cancellous bone (2~45MPa).▲Three-dimensional reconstruction images of mature sheep vertebral bone defect filling and repair 0-36 weeks post-operationCalcium sulfate and organic polymers mainly form stable structures through chemical bonds. In the study by Lewis et al., magnetic resonance detected that -COOH in CS/carmellose composite materials formed new chemical bonds with calcium ions; for different carmellose contents (5%, 7.5%, 10%), the flexural strength of the composites increased by 99%, 103%, and 124% respectively; among them, the compressive strength of the 7.5% and 10% groups increased by 88% and 85% respectively. Gao et al. also found that -COOH formed chemical bonds with calcium ions when CS and polylactic acid were compounded; under a scanning electron microscope, calcium sulfate (with calcium sulfate content below 50%) was uniformly dispersed in the polylactic acid matrix; when the CS content was 40%, the compressive strength reached its maximum, at 82 MPa.Calcium sulfate and inorganic ceramic materials mainly form a stable structure through physical connections, with different material types, crystal phases, and proportions all affecting the mechanical strength of the composite materials. The structure of calcium sulfate/hydroxyapatite is primarily maintained by the calcium sulfate matrix, with hydroxyapatite simply integrated into it; thus, as the content of calcium sulfate decreases, the mechanical strength will decrease. Among all the crystal phases of calcium sulfate, hemihydrate calcium sulfate can rapidly self-cure through hydration to form dihydrate calcium sulfate with greater hardness, which is of significant importance for early load-bearing in clinical bone defect reconstruction.Composite materials not only provide structural support and osteoconductivity, but also have a certain degree of osteoinductivity, and perform better in terms of immune rejection. The development and application of these materials have greatly enriched the options for bone repair, enhancing the flexibility and effectiveness of treatment. Through continuous research and technological advancements, synthetic bone graft materials will play an even more critical role in future medical applications.tissue engineering boneTissue engineering bone is an advanced medical technology that combines the principles of biology, engineering, and medicine to construct new bone tissue in vitro for repairing bone defects. This technology mainly involves three core elements: seed cells, biomaterial scaffolds, and growth factors. Seed cells are the basic units for tissue reconstruction, usually derived from the patient themselves or donors, to ensure biocompatibility and reduce immune rejection. Biomaterial scaffolds provide a three-dimensional porous structure that not only supports cell attachment and growth but also helps maintain cell distribution and nutrient transport. Growth factors are key factors in promoting cell proliferation and differentiation, which help accelerate tissue formation and maturation.The biomedical materials used in tissue engineering can be divided into two major categories: natural biomaterials and synthetic biomaterials. Natural biomaterials such as collagen, hydroxyapatite, and gelatin, due to their excellent biocompatibility and biodegradability, can effectively support cell adhesion, proliferation, and differentiation, and are usually non-toxic and side-effect free to the human body. The main advantage of these materials lies in their ability to provide a biochemical and biophysical environment similar to that of human cells, thereby promoting the formation and integration of new tissues. However, the primary limitations of natural materials are their poor processability and reproducibility, as well as the difficulty in precisely controlling their degradation rate, which may pose certain challenges in clinical applications.In contrast, synthetic biomaterials such as polylactic acid, polyglycolic acid, and polycaprolactone offer a wider range of options and better processability. The biodegradation rate of these materials can be adjusted as needed, and their mechanical properties can also be designed to meet specific clinical requirements. Synthetic materials are generally less expensive and have better reproducibility, making them suitable for large-scale production. However, their main disadvantage is that compared to natural materials, they have poorer biocompatibility and cell affinity, which may limit their effectiveness in certain clinical applications.Despite the relatively short development time of tissue-engineered bone, it has already shown great potential for development and application prospects. By optimizing the design of scaffold materials, improving the processing methods of seed cells, and enhancing the application strategies of growth factors, future tissue-engineered bone is expected to play a more important role in the fields of bone repair and reconstruction. The continuous development of this technology not only helps to improve the limitations of traditional bone grafting methods but also may provide more effective solutions for treating complex bone defect cases. # Cartilage Replacement and Transplant MaterialsCartilage is a special type of connective tissue, composed of cartilage cells (called chondrocytes), fibers, and matrix, with important physiological functions and structural characteristics. The structure of cartilage allows it to withstand pressure and serve as an important component of the skeletal system.Chondrocytes: Chondrocytes, or chondrocytes, are usually round or oval in shape and are located in small cavities called chondrocyte lacunae. These cells are responsible for forming fibers and secreting the matrix, and they are the active components of cartilage growth and maintenance. The area surrounding the chondrocyte lacunae is rich in chondroitin sulfate and is known as the perichondrium, which helps to protect the cells and facilitate material exchange with the surrounding matrix.Fibrous perichondrium: The outer part of the cartilage is wrapped in a fibrous perichondrium, which is a tougher connective tissue that can provide additional support and protection. It helps the cartilage to bear loads and connect with adjacent bone structures.Extracellular matrix: The extracellular matrix of cartilage is its main component, composed of collagen, proteoglycans, hyaluronic acid, as well as liquid components such as water and electrolytes. This complex network not only supports chondrocytes but also provides the essential growth microenvironment for the cells. The high water content of the matrix and the characteristics of hyaluronic acid allow substances to freely permeate through the matrix, providing nutrition to deep chondrocytes even under avascular conditions.Based on the differences in matrix composition and structure, cartilage can be divided into three types: hyaline cartilage, elastic cartilage, and fibrocartilage.Transparent cartilage is the most common type of cartilage, with its main chemical components being proteoglycans, particularly long chains of hyaluronic acid, to which many shorter proteoglycan side chains are attached. These side chains are mainly chondroitin sulfate, which binds to type I collagen fibers, forming a network structure capable of withstanding pressure. Transparent cartilage does not have periodic cross-striations and does not form distinct bundles of collagen fibers, but its structure is sufficient to withstand significant pressure and tension.Elastic cartilage contains a large amount of elastic fibers, giving it higher flexibility and elasticity. This type of cartilage is mainly found in the ear and laryngeal structures.Fibrocartilage contains more collagen fibers, providing stronger support and tensile strength. It mainly appears in areas that bear heavy pressure, such as the meniscus of the knee and intervertebral discs.Overall, the composition and properties of cartilage enable it to effectively withstand pressure and bending while providing crucial structural support in the joints and skeletal system.In clinical practice, the repair of cartilage defects mainly adopts various methods, including traditional surgical techniques and newer biotechnologies. Traditional methods such as subchondral bone drilling and microfracture techniques promote the natural repair of cartilage by stimulating the release of stem cells from the bone marrow. Debridement and lavage within the joint cavity, as well as joint reshaping, are primarily used to remove fragmented tissue and smooth the joint surface, reducing pain and improving function. In some cases, severe joint damage may require joint replacement to restore joint function.In biotechnology, tissue transplantation techniques, such as autologous or allogeneic cartilage transplantation, use healthy cartilage tissue to fill in the defective areas. Autologous chondrocyte transplantation is a more refined method, involving extracting cells from the patient's own cartilage, expanding these cells in the laboratory, and then injecting them back into the defective area, usually under the protection of an autologous periosteal flap.One of the most advanced methods is tissue engineering technology, which combines elements such as seed cells, scaffold materials, and growth factors. By cultivating and constructing specific cartilage tissues in the laboratory and then implanting them into the damaged area, this method not only provides repair materials but also promotes cell proliferation and differentiation through growth factors, thereby accelerating the cartilage regeneration process.periosteum and perichondrium substitute for articular cartilageThe periosteum is rich in nerves and blood vessels, providing nutritional and sensory functions, and contains multipotent hematopoietic stem cells and mesenchymal stem cells, which have the potential to differentiate into cartilage. Studies have shown that the periosteum, when implanted into articular cartilage defects, can promote the formation of hyaline cartilage and subchondral bone. Despite the advantages of easy access and minimal damage to the body, the clinical application of the periosteum is limited by difficulties in fixation, limited sources, and the inability to fully meet physiological mechanical requirements.2. Autologous or allogeneic cartilage and chondrocyte transplantation to replace articular cartilage:Autologous chondrocyte transplantation is a method that involves obtaining healthy chondrocytes from the non-weight-bearing areas of the patient, followed by in vitro culture and expansion, and then implanting them into the damaged cartilage area. This method has been proven to maintain the integrity of the subchondral bone and hinder fibrous repair caused by fibroblasts. Allogeneic chondrocyte transplantation shows similar repair effects to autologous chondrocyte transplantation, but immune response and cell preservation are its main issues.3. Alternative materials for artificial cartilage:Artificial cartilage replacement materials should have good biomechanical properties, excellent lubricity and wear resistance, chondrocyte growth induction, and strong bonding with the bone base and biocompatibility. Currently, commonly used highly elastic materials such as silicone rubber, polyurethane, and polyvinyl alcohol hydrogels each have their own advantages and disadvantages, for example, silicone rubber is prone to aging and failure, and the degradation performance of polyurethane needs improvement. The research focus is on improving existing materials and preparation processes, and exploring new materials.4. Engineered Cartilage:Tissue-engineered cartilage is achieved through the combination of seed cells and biological scaffolds. The ideal seed cells for cartilage tissue engineering should have the following characteristics:easy to obtain, abundant in source, with minimal damage to the bodystrong ability to proliferate in vitrohas good adhesion to the stent material.Seed cells implanted in the human body can adapt to the internal environment and maintain the characteristics of the original cartilage cells.The current research mainly focuses on autologous chondrocytes, allogeneic chondrocytes, mesenchymal stem cells, and embryonic stem cells. The selection of scaffold materials includes both naturally sourced biomaterials and artificially synthesized scaffold materials. The key lies in the design of the scaffold and the correct choice of materials to ensure the mechanical stability of the scaffold and to promote the proliferation and migration of seed cells. # Tendon tissue replacement and transplant materialsTendon is a typical regular dense connective tissue, whose main function is to connect muscles and bones, thus transmitting force when the muscle contracts, allowing the bone to move and completing various body movements. The structure and function of the tendon are closely related, mainly consisting of three parts: collagen bundles, endotenon, and tenocytes.Collagen bundles: This is the main component of tendons, consisting of a large number of parallel arranged collagen fibers. The arrangement of these fibers gives the tendon a high tensile resistance, allowing it to withstand the forces generated by muscles.Tendon matrix: is the substance that fills the space between collagen fibers, containing proteoglycans and water, helping the tendon maintain structural stability and elasticity under pressure.Tendon cells: mainly composed of fibroblasts and mesenchymal cells, distributed among the collagen fibers, responsible for synthesizing and secreting collagen and other matrix components, maintaining the structure and function of the tendon.Tendons need to adapt to high tension, and they bear great stretching loads during movement. Overuse, intense exercise, or external accidents (such as cuts, crush injuries) can all lead to tendon injuries. Common injuries include tendon tears or ruptures, which, if not treated in time, may result in permanent functional impairment or disability.The self-repair ability of tendons is very limited, mainly because the blood supply to tendons is relatively poor, and the repair process is slow and often cannot fully restore the original structure and function. In clinical settings, severe tendon injuries may require surgical repair, including suturing the ruptured tendon or using grafts to replace the damaged part.Tendon injuries are common sports injuries, especially under conditions of high-intensity or repetitive muscle use. Modern medicine has developed various methods for the repair and replacement of tendon injuries, mainly including autologous tendon transplantation, allogeneic tendon transplantation, xenogeneic tendon transplantation, and artificial tendon substitutes.autologous tendon graftAutologous tendon grafting involves using other healthy tendons from the patient for repair. The main advantage of this method is that it avoids immune rejection, as the transplant material comes from the patient themselves. In the early 20th century, Kirschner and other scholars confirmed the feasibility of this method through research on defect repair using autologous tendons. However, the main disadvantage of autologous tendon grafting is the limited availability of tendon resources, and the extraction of tendons may damage the donor site, and sometimes may lead to tears due to insufficient strength at the donor site.allogeneic tendon transplantationAllogeneic tendon transplantation uses tendons from the same species but different individuals. This method expands the resources of tendons available for transplantation. However, studies show that this transplantation method has a high failure rate, with main issues including necrosis and rejection of the implanted tendon. Additionally, there is a risk of donor virus transmission, such as hepatitis and AIDS, which limits its clinical application.allogeneic tendon transplantationAllogeneic tendon transplantation uses tendons from different species. This method theoretically provides a rich source of tendons, but immune rejection and biocompatibility issues remain the main challenges. Although chemical treatments such as the use of formaldehyde, freezing, and glutaraldehyde can reduce the immunogenicity of the tendon, these treatment methods may alter the biomechanical properties of the tendon, affecting the repair outcome.artificial tendon substituteArtificial tendon substitutes cover a wide range of materials, including alloys, plastics, nylon, and synthetic fibers. These materials are designed to mimic the function of natural tendons. However, many attempts have failed due to insufficient mechanical properties of the materials or poor compatibility with surrounding tissues. For example, although carbon fiber artificial tendons were initially considered promising, they were eventually phased out due to issues such as inability to absorb, tensile stress attenuation, and severe adhesion. Currently, researchers are exploring new materials and technologies, such as human hair keratin artificial tendons and tissue-engineered artificial tendons, in hopes of improving the performance and biocompatibility of artificial tendons.Human hair keratin artificial tendon (HHKAT)Human hair keratin artificial tendon uses keratin from human hair as raw material, which after special biochemical treatment, forms a biomaterial that can be used for tendon repair. The main advantages of this material include:Good biocompatibility: Human hair keratin artificial tendons have good biocompatibility, can gradually tendonize into autogenous tendons in the body, and do not show significant adhesion to surrounding tissues.No immune rejection response: Due to special treatment, this artificial tendon does not cause an immune rejection response in the body.Durable mechanical properties: Tensile stress does not decrease, capable of withstanding long-term muscle movement tension.Tendon engineering: the process of being absorbed in the body while forming new autogenous tendons is called tendon engineering.The development of this material marks an important advancement in artificial tendon technology, especially in improving the functionality of tendon repair and reducing surgical complications. 2. Tissue-engineered artificial tendonTissue-engineered artificial tendons use tendon seed cells and biodegradable materials in a composite manner, which after being cultured in vitro, are implanted into the defective area to promote the proliferation and differentiation of tendon cells, ultimately forming new tendon tissue. The main advantages of this method include:High degree of natural repair: the formed tendon tissue is vibrant and functional, capable of achieving permanent replacement.Perfect reconstruction of form and function: It can be shaped according to the specific morphology of the deficient tendon, achieving a highly matched morphological repair and functional reconstruction.No immune response and pathogen transmission risk: The seed cells used can be autologous cells, reducing the risk of immune rejection and disease transmission.The key to tissue engineering technology lies in selecting the appropriate seed cells and scaffold materials, as well as effectively combining the seed cells with the scaffold materials. The scaffold materials should not only have good mechanical strength to support early activities but also be able to degrade in sync with cell functions, providing space for cell growth and physiological functions. orthopedic internal fixation materialsOrthopedic internal fixation materials refer to various medical devices used for internal fixation, which can be implanted in the body to stabilize and support conditions such as fractures, deformities, and bone defects after tumor resection. These materials are designed to withstand the challenges of the in-body environment, such as biocompatibility, corrosion resistance, and sufficient mechanical strength to support the bone healing process. Orthopedic internal fixation materials can be classified according to their type, purpose, and material used. The main types include:In fracture treatment, internal fixation technology is a key method for restoring stability to the fracture site, allowing for early weight-bearing and limb movement, thereby promoting fracture healing. The selection and application of internal fixation involve multiple factors such as the type of fracture, patient age, and prognosis expectations. For the stability of the fracture, the influence of the following five main forces needs to be considered:Compressive force: transmitted axially, increasing the load on the bone, commonly seen in compression fractures of the spine.Tension: also transmitted axially, causing fracture separation.Bending force: causes one side of the bone to bear pressure while the opposite side bears tension.Torque: subjecting the bone to rotational force.Shear force: caused by compressive force, leading to oblique fracture.To ensure the effectiveness and safety of orthopedic internal fixation materials, the materials used need to meet the following key conditions:has sufficient strengthInternal fixation devices must have sufficient strength to support the load during the fracture healing process. The characteristics of different materials are as follows:Stainless steel: has good mechanical properties and cost-effectiveness, is easy to process, and is widely used in the manufacture of various internal fixation devices. It has relatively high bioactivity but may corrode under high load conditions.Cobalt-chromium-molybdenum alloy: low biological activity, with extremely high corrosion resistance and mechanical strength, but high cost and difficult to process.Titanium alloy: lightweight, strong corrosion resistance, with good biocompatibility and lower biological activity. The elasticity of titanium alloy is close to that of human bone, making it suitable for the manufacture of long-term implants. It produces almost no artifacts in CT and MRI examinations, facilitating follow-up checks.Degradable materials mainly based on polylactic acid: good biocompatibility, can naturally degrade into water and carbon dioxide after use, eliminating the need for a second surgery to remove. Suitable for internal fixation scenarios that do not bear high loads. The long-term biological safety of its application is still under study.2. unorganized responseThe material should be biocompatible, not causing toxic reactions, inflammation, fibrosis, or macrophage activation. These biological responses may cause pain, swelling, and functional impairment in the implant area, and in rare cases, may even lead to tumor formation. Therefore, for young people, it is generally recommended to remove the internal fixation device once the fracture has healed.3. does not corrodeThe implant should not rust or produce an electrolytic reaction. When using stainless steel, it should be ensured that its purity is high and free of impurities to prevent corrosion. In addition, measures should be taken to prevent contact between different internal fixation materials to avoid interface corrosion. Using internal fixation components of the same material is also an effective way to prevent electrolytic corrosion.the evolution of internal fixation techniquesThe AO/ASIF system is a classic internal fixation system, created by Mueller and other orthopedic surgeons in 1956. This concept primarily focuses on achieving anatomical reduction and stabilization of fractures through internal fixation techniques to promote direct healing of the fracture. The AO team developed a comprehensive internal fixation system, including screws, plates, intramedullary nails, etc., as well as detailed surgical techniques and principles. The core principles of the AO concept include:anatomical reduction of the fracture ends: especially for intra-articular fractures, it is emphasized that a perfect anatomical reduction must be achieved as much as possible.Strong internal fixation: providing sufficient stability to meet biomechanical requirements through a precisely designed internal fixation system.Non-invasive surgical techniques: During the operation, protect the blood supply of the fracture ends and surrounding soft tissues as much as possible, and reduce additional injuries caused by the surgery.Early activity: Through stable internal fixation support, patients can start muscle and joint activities as early as possible to prevent complications from prolonged bed rest.AO perspective emphasizes that mechanical stability is the key to achieving fracture healing, and the precision of the operation and the quality of internal fixation directly affect the success of the treatment.BO perspective, which refers to biological fixation concepts, is a complement and development of the AO perspective. It gradually took shape from the late 20th century to the early 21st century, mainly emphasizing the maintenance or restoration of the biological environment and blood supply in the fracture area during fracture treatment. The BO perspective posits that excessive mechanical fixation may have negative impacts on the biological environment of the fracture site, such as stress shielding leading to osteoporosis, and damage to soft tissues caused by the surgery itself. Therefore, the BO perspective proposes the following principles:Protect soft tissues and blood supply: Minimize disruption to the fracture area and surrounding soft tissues during surgery, maintaining blood supply.Moderate internal fixation: using materials with good biocompatibility and low elastic modulus to reduce stress shielding on the bone and promote fracture healing.Avoid excessive reduction: For comminuted fractures, do not insist on complete anatomical reduction, especially for extra-articular fractures.Minimally invasive surgical techniques: Using minimally invasive techniques to reduce the overall impact of surgery on the patient and accelerate recovery.Minimally invasive internal fixation technique (MIPO): In recent years, the development of minimally invasive surgical techniques aims to reduce damage to soft tissues, thereby protecting blood supply and promoting faster healing.As the understanding of fracture treatment deepens, traditional views on mechanical fixation are gradually shifting towards biological fixation. Biological fixation takes into account the following points:Protect local soft tissues: perform reduction away from the fracture site to protect the attachment of local soft tissues.Do not insist on anatomical reduction of comminuted fracture fragments: unless it is an intra-articular fracture, there is no need to pursue perfect anatomical reduction.Use biocompatible materials: such as low elastic modulus materials, to reduce the contact between internal fixation and bone, thereby reducing the stress shielding effect.Reduce surgical exposure time: Minimize the duration of surgery to lessen the overall impact on the patient. # Orthopedic External Fixator Bracket and ApplicationOrthopedic external fixator is a medical device used in fracture treatment and orthopedic surgery, which stabilizes the fractured area or corrects deformities through an external fixation frame. They are fixed to the bones with skin-penetrating needles or pins, and the external structure provides the necessary support and stability to promote fracture healing or correct bone deformities. External fixators are suitable for complex fractures that cannot use internal fixation, infections, or situations requiring progressive adjustments.External bone fixator is actually a third type of fixation method between orthopedic internal fixation and external fixation, which provides partial immobilization for fractures or dislocations with minimal trauma. It combines the advantages of both internal and external fixation. Compared to internal fixation, it causes less damage and has a lower infection rate. Compared to external fixation methods such as small splints and plaster, it offers more reliable and stable fixation. However, it also has its own limitations and drawbacks, so when choosing to use an external bone fixator, one should strictly adhere to their indications and contraindications.External fixators are mainly composed of fixation pins, connecting rods, and fixing bolts and nuts. Fixation pins are used to penetrate into the bone to hold it in place, with the pin tails remaining outside the body, connected and fixed by the connecting rods. The main types of fixation pins include Steinmann pins, commonly used for adult lower limb fractures; Kirschner pins, often used for adult upper limb fractures and children's upper and lower limb fractures; half-threaded pins (Schanz pins) with a threaded tip, frequently used for half-pin fixation; and threaded pins with a threaded middle section, typically used for full-pin fixation. Connecting rods serve to connect and stabilize the pin tails, commonly seen in tubular steel, threaded rod, and hook groove styles. Fixing bolts and nuts primarily function to connect and secure the fixation pins and connecting rods.Orthopedic external fixators can be classified according to their design, function, and purpose of use. The main types include:unilateral external fixatorDefinition: The fixture is located on one side of the fracture, fixing the bone fragments through connecting rods and pin nails.Application: Suitable for simpler fractures or when local skin conditions do not allow the use of circular or bilateral fixators.bilateral or multi-lateral external fixatorDefinition: The fixture is located on both sides or multiple sides of the fracture, providing more uniform support and stability through multiple connecting rods and pin sales.Application: Suitable for more stable fixation in complex fractures or reconstructive surgery.circular external fixator (such as the Ilizarov device)Definition: A series of ring structures are used to fix fractures or deformities by wires or pins, with the rings connected by rods.Application: Widely used for complex fractures, long bone lengthening surgeries, or severe deformity corrections. Particularly in pediatric orthopedics, it is used to treat severe limb deformities.hybrid external fixatorDefinition: Combining the characteristics of ring and unilateral or bilateral fixators, utilizing the ring structure to provide stability, while using unilateral or bilateral supports for local adjustments.Application: Suitable for extremely complex fractures or highly customized deformity corrections.dynamic external fixatordefinition: allow or control the movement of a specific joint while immobilizing the surrounding fracture area.Application: Mainly used for the treatment of fractures near joints, it can ensure fracture stability while promoting joint function recovery.When selecting an appropriate external fixator, the following factors need to be considered:Fracture type and location: Different types of external fixators are suitable for different types and locations of fractures.The patient's age and health condition: factors such as bone density, skin condition in children and adults may affect the choice of external fixator.Treatment goal: whether dynamic adjustment or long-term wear is needed, and whether future functional recovery should be considered.The complexity and maintenance of external fixators: some complex devices may require more frequent monitoring and adjustment by the patient and medical team. # Orthopedic Biodegradable Internal Fixation MaterialsSince the late 1960s, scientists have been exploring and developing the application of biodegradable materials in medicine. Polylactic acid (PLA), as a biodegradable and absorbable material, has achieved certain good results in the surgical treatment of orthopedic diseases due to its excellent biocompatibility, reliable mechanical strength, non-toxic side effects, and convenience of use without the need for a second surgery to remove it. Over the years, the most common absorbable materials on the market have been polylactic acid-based absorbable polyester materials, such as poly-L-lactic acid (PLLA), lactide-caprolactone copolymer (PLGA), and polycaprolactone (PCL). The synthesis principles and pathways of these materials are similar to those of PLA, and different materials can be "hybridized" to form copolymers, thus resulting in a wide variety of final products.A wide variety of biodegradable screws, nails, rods, bone plates, biological membranes, sutures, intervertebral fusion devices, and other products have been researched and widely used in orthopedic clinical surgeries. Due to their special advantages, they are increasingly being used by orthopedic surgeons to replace traditional metal materials.absorbable interface screwIn terms of the development of materials science, polylactic acid (PLA) and polymer materials were almost born at the same time. As early as the 18th century in Europe, people isolated lactic acid from fermented milk and obtained the most primitive PLA through direct polycondensation. Lactic acid is a chiral molecule, existing in two optical isomers: left-handed (L) and right-handed (D) lactic acid, which can form four different types of polymers: PDLA, PLLA, PDLLA, and meso-PLA, each with distinct properties. Among them, PDLLA and PLLA are two stereoregular polymers, possessing optical activity, with relatively regular polymer chain arrangements, high crystallinity, and mechanical strength, making them suitable for applications requiring high mechanical strength and toughness, such as sutures, nails, and orthopedic devices. Numerous experimental studies have confirmed that the degradation of PLA is a simple hydrolysis process that does not require the participation of other enzymes; it can be hydrolyzed into lactic acid in the body, entering the tricarboxylic acid cycle, with the final products being water and carbon dioxide, which are metabolized and excreted by the body.Compared to traditional metal materials, bioabsorbable implants have various advantages; during the degradation process, external force loads are gradually transferred to the bone, effectively avoiding osteoporosis caused by stress shielding; the optimal degradation rate is designed according to the usage of different repair sites, reducing secondary surgical injuries to patients; they have good biocompatibility, are safe and non-toxic, and since polymer materials do not have metallic magnetism, they will not interfere with or affect medical imaging examinations and security checks.Absorbable internal fixation implant devices have been accepted and recognized by doctors and patients, gradually replacing the use of metal devices, but there are still some issues that need to be resolved and improved:The strength of absorbable fixation devices is lower than that of metal devices, thus limiting their application range. In the early postoperative period, it is also necessary to cooperate with necessary external fixation. In terms of biomechanics, the yield strength of L-PLA is 70MPa, and the elongation rate is only 5%~10%, which is not sufficient to meet its application in bone tissue repair and surgical sutures. The main defect of bioabsorbable internal fixation materials compared to metal materials is precisely in the mechanical strength and the uncontrollable process of strength attenuation during absorption. Therefore, many scholars have conducted a large amount of research in this area. Since the 1980s, the application of new plastic reinforcement techniques (including self-reinforcement, in-situ synthesis, and stretching, etc.) has led to rapid development in the research of bioabsorbable materials, resulting in a significant increase in effective strength compared to PLLA.In recent years, to improve the insufficient mechanical properties of PLA, self-reinforcement technology has been invented, which involves sintering suture fibers together under high temperature and high pressure to produce self-reinforced cylindrical PLA rods. Tormala et al. used self-reinforcement technology to produce self-reinforced poly-L-lactic acid (SR-PLLA) rods and screws, with initial bending strength r

Material Innovation: Performance Breakthrough of PAEKPAEK (Polyaryletherketone) as the fourth-generation medical polymer material, achieves three core breakthroughs through unique molecular design:Biomechanical adaptability: 3-4 GPa elastic modulus forms a gradient match with cortical bone (3-30 GPa), effectively avoiding the stress shielding effect of metal implantsChemical stability: annual hydrolysis rate 0.1%, passed the full set of biocompatibility certification according to ISO 10993-1Imaging compatibility: X-ray transmittance 90%, CT value 110-130 HU close to soft tissue, MRI without artifact interferenceII. Material System: Molecular Structure Determines Performance DifferencesPAEK family main members technical parameters comparison:III. Clinical Application: From Substitute to Functional TherapyOrthopedic innovationSpinal fusion: PEEK interbody fusion device 5-year reoperation rate reduced by 36% compared to titanium alloyJoint replacement: PEKK acetabular cup with ceramic femoral head has a wear rate as low as 0.03 mm³/million cyclesTrauma repair: PAEK/HA composite material bone bonding strength reaches 25 MPa (FDA standard 15 MPa)precision medicine3D printed cranial repair: gradient pore structure (500-800μm) reduces infection rate by 74%Degradable system: PAEK-g-PLLA bone nail completely degrades within 2 years, with strength maintained for 6-8 monthsminimally invasive technologySurgical instruments: PAEK blend material reduces the weight of the Da Vinci surgical forceps by 57%, with precision improved to 0.1mmNeurointervention: PAEK embolization coil MRI visibility is 3 times higher than platinum alloyIV. Industry Structure: A Trillion-Yuan Market Driven by Technologyglobal situation2023 year market size 14.2 billion USD, 2024-2030 CAGR 9.8%North America accounts for 42% of the share, with an annual growth rate of 15% in the Asia-Pacific region, and China becomes the largest incremental market.domestic breakthroughPaiwo achieves full industry chain technology breakthrough:molecular weight control accuracy reaches ±5%impurity content 50ppmpilot scale yield 92%Domestic PEKK price is 40-60% lower than imported, with production capacity exceeding 80 tons/yearV. Technical Challenges and Innovation Pathwayskey bottleneckRaw material end: Arkema monopolizes 92% of the medical-grade resin marketDevice end: The unit price of imported laser sintering equipment exceeds 2 million US dollarsClinical end: 60% of physicians are concerned about long-term safetyfuture directionMaterial Design: AI Predicts Interfacial Energy, Developing Biomimetic Mineralized CompositesManufacturing Technology: 4D Printing Achieves Body Temperature Responsive DeformationEmerging applications: drug delivery devices, neural repair scaffolds, etc.Appendix: Glossary of Terms 

Sure, please provide the content that needs to be translated. It seems like the actual text is missing from your request. Once you provide the text, I can translate it for you while keeping the HTML tags and URLs intact.In the medical field, plastic products must meet specific standards of chemical stability and biological safety due to their potential contact with medications or the human body.In short, medical plastics should not release harmful substances during use, avoiding toxicity or injury to tissues and organs, and maintaining harmlessness to the human body.To ensure the biological safety of medical plastics, all medical plastic products sold on the market need to undergo strict certification and testing by authoritative institutions in the healthcare industry. Additionally, it is necessary to clearly indicate to users which specific plastic models are designed for medical purposes, i.e., medical-grade plastics.Medical devices come in a wide variety, including in vitro diagnostic reagents, medical consumables, medical equipment, and pharmaceutical equipment. Due to the advantages of low cost, ease of processing, light weight, and good toughness, plastics are increasingly being used in medical devices. 01Polycarbonate PCPolycarbonate (PC) is a general term for a class of high molecular polymers containing carbonate groups in their molecular chains. Depending on the type of ester group, they can be divided into aliphatic PCs, alicyclic PCs, and aromatic PCs, etc.PC is a thermoplastic engineering plastic with excellent transparency, impact resistance, heat resistance, and mechanical strength.The synthesis of PC usually involves two processes: phosgene method and non-phosgene method.Phosgene method: This includes solution phosgenation, interfacial polycondensation, and transesterification. Interfacial polycondensation is currently the most commonly used method, involving the reaction between bisphenol A sodium salt and phosgene to produce polycarbonate. This method is mature, stable in production, and easy to control.Non-phosgene method: This mainly involves the transesterification reaction between dimethyl carbonate and phenol to produce diphenyl carbonate, followed by transesterification and polycondensation reactions with bisphenol A to generate polycarbonate. This method is referred to as a "green process" because it does not use toxic phosgene as a raw material, making it safer for the environment and operators. 02Sure, please provide the content that needs to be translated.In the medical field, plastic products must meet specific standards of chemical stability and biological safety due to their potential contact with drugs or the human body.In short, medical plastics should not release harmful substances during use, avoiding toxicity or damage to tissues and organs, and maintaining harmlessness to the human body.To ensure the biological safety of medical plastics, all medical plastic products sold on the market must undergo strict certification and testing by authoritative institutions in the medical industry. In addition, it is necessary to clearly indicate to users which specific plastic models are designed for medical purposes, i.e., medical-grade plastics.Medical devices come in a wide variety, including in vitro diagnostic reagents, medical consumables, medical equipment, and pharmaceutical equipment. Due to the advantages of low cost, ease of processing, light weight, and good toughness, plastics are increasingly being used in medical devices. 01Polycarbonate PCPolycarbonate (PC) is a general term for a class of high molecular polymers containing carbonate groups. Depending on the type of ester group, they can be classified as aliphatic PC, alicyclic PC, and aromatic PC, etc.PC is a thermoplastic engineering plastic with excellent transparency, impact resistance, heat resistance, and mechanical strength.The synthesis of PC typically involves two processes: phosgene method and non-phosgene method.Phosgene method: This includes solution phosgenation, interfacial polycondensation, and transesterification. Interfacial polycondensation is currently the most commonly used method, involving the reaction between sodium salt of bisphenol A and phosgene to produce polycarbonate. This method is mature, stable in production, and easy to control.Non-phosgene method: This mainly involves the transesterification reaction between dimethyl carbonate and phenol to produce diphenyl carbonate, which then undergoes transesterification and polycondensation reactions with bisphenol A to produce polycarbonate. This method is known as a "green process" because it does not use toxic phosgene as a raw material, making it safer for the environment and operators. 02In the medical field, plastic products must meet specific standards of chemical stability and biological safety due to their potential contact with drugs or the human body.In short, medical plastics should not release harmful substances during use, avoiding toxicity or damage to tissues and organs, and maintaining harmlessness to the human body.To ensure the biological safety of medical plastics, all medical plastic products sold on the market must undergo strict certification and testing by authoritative institutions in the medical industry. In addition, it is necessary to clearly indicate to users which specific plastic models are designed for medical purposes, i.e., medical-grade plastics.Medical devices come in a wide variety, including in vitro diagnostic reagents, medical consumables, medical equipment, and pharmaceutical equipment. Due to the advantages of low cost, ease of processing, light weight, and good toughness, plastics are increasingly widely used in medical devices. 01Polycarbonate PC01Polycarbonate PC01Polycarbonate PC0101010101010101Polycarbonate PCPolycarbonate PCPolycarbonate PCPolycarbonate PCPolycarbonate PCPolycarbonate PCPolycarbonate (PC) is a general term for a class of high molecular weight polymers that contain carbonate groups in their molecular chains. Depending on the type of ester group, they can be classified as aliphatic PC, alicyclic PC, and aromatic PC, etc.Polycarbonate (PC) is a general term for a class of high molecular weight polymers that contain carbonate groups in their molecular chains. Depending on the type of ester group, they can be classified as aliphatic PC, alicyclic PC, and aromatic PC, etc.PC is a thermoplastic engineering plastic with excellent transparency, impact resistance, heat resistance, and mechanical strength.The synthesis of PC typically involves two processes: the phosgene process and the non-phosgene process.Phosgene process: This includes solution phosgenation, interfacial polycondensation, and transesterification. Interfacial polycondensation is currently the most commonly used method, which involves the reaction between sodium salt of bisphenol A and phosgene to produce polycarbonate. This method is mature, stable in production, and easy to control.Non-phosgene process: This mainly involves the ester exchange reaction between dimethyl carbonate and phenol to produce diphenyl carbonate, followed by an ester exchange and polycondensation reaction with bisphenol A to form polycarbonate. This method is known as a "green process" because it does not use toxic phosgene as a raw material, making it safer for the environment and operators.Phosgene process: This includes solution phosgenation, interfacial polycondensation, and transesterification. Interfacial polycondensation is currently the most commonly used method, which involves the reaction between sodium salt of bisphenol A and phosgene to produce polycarbonate. This method is mature, stable in production, and easy to control.Non-phosgene process: This mainly involves the ester exchange reaction between dimethyl carbonate and phenol to produce diphenyl carbonate, followed by an ester exchange and polycondensation reaction with bisphenol A to form polycarbonate. This method is known as a "green process" because it does not use toxic phosgene as a raw material, making it safer for the environment and operators.Phosgene process: This includes solution phosgenation, interfacial polycondensation, and transesterification. Interfacial polycondensation is currently the most commonly used method, which involves the reaction between sodium salt of bisphenol A and phosgene to produce polycarbonate. This method is mature, stable in production, and easy to control.Phosgene process: This includes solution phosgenation, interfacial polycondensation, and transesterification. Interfacial polycondensation is currently the most commonly used method, which involves the reaction between sodium salt of bisphenol A and phosgene to produce polycarbonate. This method is mature, stable in production, and easy to control.Non-phosgene process: This mainly involves the ester exchange reaction between dimethyl carbonate and phenol to produce diphenyl carbonate, followed by an ester exchange and polycondensation reaction with bisphenol A to form polycarbonate. This method is known as a "green process" because it does not use toxic phosgene as a raw material, making it safer for the environment and operators.Non-phosgene process: This mainly involves the ester exchange reaction between dimethyl carbonate and phenol to produce diphenyl carbonate, followed by an ester exchange and polycondensation reaction with bisphenol A to form polycarbonate. This method is known as a "green process" because it does not use toxic phosgene as a raw material, making it safer for the environment and operators.Non-phosgene method: This mainly involves the ester exchange reaction between dimethyl carbonate and phenol to produce diphenyl carbonate, which then undergoes ester exchange and condensation reactions with bisphenol A to generate polycarbonate. This method is referred to as a "green process" because it does not use toxic phosgene as a raw material, making it safer for the environment and operators.  02Medical-grade PC02Medical-grade PC02Medical-grade PC0202020202020202Medical-grade PCMedical-grade PCMedical-grade PCMedical-grade PCMedical-grade PCMedical-grade PCChina started relatively late in the field of medical plastic products, beginning to research and produce plastic infusion bags only in the 1970s.China started relatively late in the field of medical plastic products, beginning to research and produce plastic infusion bags only in the 1970s.In 1987, the Ministry of Health issued a notice on promoting the use of disposable plastic infusion sets, blood transfusion sets, and syringes. The implementation of this policy greatly promoted the development and production of medical plastic products in China, while also improving the safety and convenience of medical supplies, thus driving the rapid development of related industries.In 1987, the Ministry of Health issued a notice on promoting the use of disposable plastic infusion sets, blood transfusion sets, and syringes. The implementation of this policy greatly promoted the development and production of medical plastic products in China, while also improving the safety and convenience of medical supplies, thus driving the rapid development of related industries.In the field of medical devices, there is a series of specific performance requirements for the polymer materials used to ensure their safety and effectiveness. Common requirements are as follows:Chemical stability: The material should have excellent chemical resistance, ensuring that it maintains its properties throughout the expected usage period, even during routine disinfection processes without being damaged.Processability: The material should be easy to process, facilitating the manufacture of various complex-shaped medical products.Biological safety: It must be non-toxic, free from risks of causing cancer, teratogenic effects, or genetic mutations, not induce pyrogenic reactions, and the content of leachables and extractables should be controlled at extremely low levels.Tissue compatibility: The material should not damage surrounding tissues, interfere with the body's immune response, or lead to calcification on the surface of the material.Blood compatibility: When in contact with blood, the material should exhibit good anticoagulant properties, avoiding hemolysis, reduction in the number of blood cells, denaturation of proteins in the blood, or destruction of formed elements in the blood.Long-term stability: After implantation in the human body, the material should demonstrate good stability, and its mechanical properties should remain stable over long-term use, without significant changes (for non-degradable materials).These requirements ensure that the application of polymer materials in medical devices is not only safe and effective but also meets the needs of long-term clinical use.In the field of medical devices, there are a series of specific performance requirements for the high molecular materials used to ensure their safety and effectiveness. The common requirements are as follows:Chemical stability: It should have excellent chemical resistance, ensuring that its performance is maintained over the expected service life, even during routine disinfection processes without being damaged.Processability: The material should be easy to process, making it convenient to manufacture into various complex shapes of medical products.Biological safety: It must be non-toxic, with no risk of causing cancer, teratogenicity, or genetic mutations, not causing pyrogenic reactions, and the content of leachables and extractables should be controlled at very low levels.Tissue compatibility: The material should not damage surrounding tissues, not interfere with the human immune response, and not cause calcification on the surface of the material.Blood compatibility: When the material comes into contact with blood, it should have good anticoagulant properties, avoiding hemolysis, reduction in blood cell count, denaturation or destruction of proteins in the blood, or other formed elements in the blood.Long-term stability: After implantation in the human body, the material should exhibit good stability, and its mechanical properties should remain stable over long-term use, without significant changes (for non-degradable materials).These requirements ensure that the application of high molecular materials in medical devices is not only safe and effective but also meets the needs of long-term clinical use.In the field of medical devices, there are a series of specific performance requirements for the high molecular materials used to ensure their safety and effectiveness. The common requirements are as follows:In the field of medical devices, there are a series of specific performance requirements for the high molecular materials used to ensure their safety and effectiveness. The common requirements are as follows:In the field of medical devices, there are a series of specific performance requirements for the high molecular materials used to ensure their safety and effectiveness. The common requirements are as follows:Chemical stability: It should have excellent chemical resistance, ensuring that its performance is maintained over the expected service life, even during routine disinfection processes without being damaged.Chemical stability: It should have excellent chemical resistance, ensuring that its performance is maintained over the expected service life, even during routine disinfection processes without being damaged.Chemical stability: It should have excellent chemical resistance, ensuring that its performance is maintained over the expected service life, even during routine disinfection processes without being damaged.Processability: The material should be easy to process, making it convenient to manufacture into various complex shapes of medical products.Processability: The material should be easy to process, making it convenient to manufacture into various complex shapes of medical products.Processability: The material should be easy to process, making it convenient to manufacture into various complex shapes of medical products.Biological safety: Must be non-toxic, without the risk of causing cancer, teratogenicity, or genetic mutations, and should not cause pyrogenic reactions. The content of leachables and extractables should be controlled at an extremely low level.Biological safety: Must be non-toxic, without the risk of causing cancer, teratogenicity, or genetic mutations, and should not cause pyrogenic reactions. The content of leachables and extractables should be controlled at an extremely low level.Biological safety: Must be non-toxic, without the risk of causing cancer, teratogenicity, or genetic mutations, and should not cause pyrogenic reactions. The content of leachables and extractables should be controlled at an extremely low level.Tissue compatibility: The material should not damage surrounding tissues, interfere with the body's immune response, or lead to calcification on the material surface.Tissue compatibility: The material should not damage surrounding tissues, interfere with the body's immune response, or lead to calcification on the material surface.Tissue compatibility: The material should not damage surrounding tissues, interfere with the body's immune response, or lead to calcification on the material surface.Blood compatibility: When in contact with blood, the material should have good anticoagulant properties, avoiding hemolysis, reduction in blood cell count, denaturation of proteins in the blood, or destruction of formed elements in the blood.Blood compatibility: When in contact with blood, the material should have good anticoagulant properties, avoiding hemolysis, reduction in blood cell count, denaturation of proteins in the blood, or destruction of formed elements in the blood.Blood compatibility: When in contact with blood, the material should have good anticoagulant properties, avoiding hemolysis, reduction in blood cell count, denaturation of proteins in the blood, or destruction of formed elements in the blood.Long-term stability: After being implanted in the human body, the material should exhibit good stability, and its mechanical properties should remain stable over long-term use, without significant changes (for non-degradable materials).Long-term stability: After being implanted in the human body, the material should exhibit good stability, and its mechanical properties should remain stable over long-term use, without significant changes (for non-degradable materials).Long-term stability: After being implanted in the human body, the material should exhibit good stability, and its mechanical properties should remain stable over long-term use, without significant changes (for non-degradable materials).These requirements ensure that polymer materials used in medical devices are not only safe and effective but also meet the needs for long-term clinical use.These requirements ensure that polymer materials used in medical devices are not only safe and effective but also meet the needs for long-term clinical use.These requirements ensure that polymer materials used in medical devices are not only safe and effective but also meet the needs for long-term clinical use.Currently, medical plastics mainly include engineering plastics and biodegradable materials, as well as some special materials such as silicone. There are many types of medical plastics, approximately a dozen, among which the market share of medical-grade polycarbonate (PC) is continuously increasing.Currently, medical plastics mainly include engineering plastics and biodegradable materials, as well as some special materials such as silicone. There are many types of medical plastics, approximately a dozen, among which the market share of medical-grade polycarbonate (PC) is continuously increasing.Polycarbonate (PC) is widely used in the medical industry due to its unique material properties.Polycarbonate (PC) is widely used in the medical industry due to its unique material properties.Transparency: PC has extremely high transparency, which is very important for medical devices that require optical clarity.Impact resistance: PC has excellent impact resistance and can maintain its physical properties even at low temperatures, making it suitable for applications that require withstanding impacts.Heat resistance: PC has a relatively high glass transition temperature (Tg), allowing it to be used over a wide temperature range, which is suitable for medical equipment requiring high-temperature sterilization.Chemical resistance: PC shows good resistance to most inorganic acids, alkalis, and salts, making it suitable for use during chemical disinfection processes.Biocompatibility: PC has good biocompatibility and can be compatible with human tissues, making it suitable for implantable medical devices.Processability: PC is easy to process and can be shaped through injection molding, extrusion, and other methods. Its adaptability makes it suitable for manufacturing complex components of medical equipment.Environmental stability: PC has good resistance to water, oil, and many chemicals, making it suitable for use in various medical environments.Transparency: PC has extremely high transparency, which is very important for medical devices that require optical clarity.Impact resistance: PC has excellent impact resistance and can maintain its physical properties even at low temperatures, making it suitable for applications that require withstanding impacts.Heat resistance: PC has a relatively high glass transition temperature (Tg), allowing it to be used over a wide temperature range, which is suitable for medical equipment requiring high-temperature sterilization.Chemical resistance: PC shows good resistance to most inorganic acids, alkalis, and salts, making it suitable for use during chemical disinfection processes.Biocompatibility: PC has good biocompatibility and can be compatible with human tissues, making it suitable for implantable medical devices.Processability: PC is easy to process and can be shaped through injection molding, extrusion, and other methods. Its adaptability makes it suitable for manufacturing complex components of medical equipment.Environmental stability: PC has good resistance to water, oil, and many chemicals, making it suitable for use in various medical environments.Transparency: PC has extremely high transparency, which is very important for medical devices that require optical clarity.Transparency: PC has extremely high transparency, which is very important for medical devices that require optical clarity.Transparency: PC has extremely high transparency, which is very important for medical devices that require optical clarity.Impact resistance: PC has excellent impact resistance and can maintain its physical properties even at low temperatures, making it suitable for applications that require withstanding impacts.Impact resistance: PC has excellent impact resistance and can maintain its physical properties even at low temperatures, making it suitable for applications that require withstanding impacts.Impact resistance: PC has excellent impact resistance and can maintain its physical properties even at low temperatures, making it suitable for applications that require withstanding impacts.Heat resistance: PC has a high glass transition temperature (Tg) and can be used over a wide temperature range, making it suitable for medical devices that require high-temperature sterilization.Heat resistance: PC has a high glass transition temperature (Tg) and can be used over a wide temperature range, making it suitable for medical devices that require high-temperature sterilization.Heat resistance: PC has a high glass transition temperature (Tg) and can be used over a wide temperature range, making it suitable for medical devices that require high-temperature sterilization.Chemical resistance: PC has good resistance to most inorganic acids, bases, and salts, making it suitable for use in chemical disinfection processes.Chemical resistance: PC has good resistance to most inorganic acids, bases, and salts, making it suitable for use in chemical disinfection processes.Chemical resistance: PC has good resistance to most inorganic acids, bases, and salts, making it suitable for use in chemical disinfection processes.Biocompatibility: PC has good biocompatibility and can be compatible with human tissues, making it suitable for implantable medical devices.Biocompatibility: PC has good biocompatibility and can be compatible with human tissues, making it suitable for implantable medical devices.Biocompatibility: PC has good biocompatibility and can be compatible with human tissues, making it suitable for implantable medical devices.Processability: PC is easy to process and can be formed through injection molding, extrusion, and other methods, offering strong adaptability and suitability for manufacturing complex medical device components.Processability: PC is easy to process and can be formed through injection molding, extrusion, and other methods, offering strong adaptability and suitability for manufacturing complex medical device components.Processability: PC is easy to process and can be formed through injection molding, extrusion, and other methods, offering strong adaptability and suitability for manufacturing complex medical device components.Environmental stability: PC has good resistance to water, oil, and many chemicals, making it suitable for use in various medical environments.Environmental stability: PC has good resistance to water, oil, and many chemicals, making it suitable for use in various medical environments.Environmental stability: PC has good resistance to water, oil, and many chemicals, making it suitable for use in various medical environments.Due to the extremely high requirements for material safety and reliability in the medical industry, these characteristics of polycarbonate make it an indispensable material in the medical field.Due to the extremely high requirements for material safety and reliability in the medical industry, these characteristics of polycarbonate make it an indispensable material in the medical field.However, it should also be noted that under certain conditions, polycarbonate may release bisphenol A (BPA), thus its use in some applications, such as baby bottles and certain medical devices, has been restricted and scrutinized.However, it should also be noted that under certain conditions, polycarbonate may release bisphenol A (BPA), thus its use in some applications, such as baby bottles and certain medical devices, has been restricted and scrutinized.  03Medical-grade PC Applications03Medical-grade PC Applications03Medical-grade PC Applications0303030303030303Medical-grade PC ApplicationsMedical-grade PC ApplicationsMedical-grade PC ApplicationsMedical-grade PC ApplicationsMedical-grade PC ApplicationsMedical-grade PC ApplicationsMedical Devices: Due to its heat resistance, chemical resistance, and transparency, PC is used in the manufacturing of medical devices such as syringes, dialyzers, and surgical instruments.Diagnostic Equipment: Polycarbonate is used to manufacture transparent parts of some diagnostic equipment, such as lenses and cover glasses for optical microscopes.Artificial Organs: The biocompatibility of PC makes it one of the ideal materials for artificial organs (such as heart valves and artificial blood vessels).Drug Delivery Systems: Polycarbonate is used in the design and manufacture of drug delivery systems, such as capsules and implants for controlled-release drugs.Housings and Protective Covers for Medical Equipment: The impact resistance and transparency of PC make it suitable for manufacturing housings and protective covers for medical equipment.Medical Devices: Due to its heat resistance, chemical resistance, and transparency, PC is used in the manufacturing of medical devices such as syringes, dialyzers, and surgical instruments.Diagnostic Equipment: Polycarbonate is used for making transparent parts of some diagnostic equipment, such as lenses and cover glasses for optical microscopes.Artificial Organs: The biocompatibility of PC makes it one of the ideal materials for artificial organs (such as heart valves, artificial blood vessels).Drug Delivery Systems: Polycarbonate is used in the design and manufacture of drug delivery systems, such as capsules and implants for controlled-release drugs.Housings and Protective Covers for Medical Equipment: The impact resistance and transparency of PC make it suitable for manufacturing housings and protective covers for medical equipment.Medical Devices: Due to its heat resistance, chemical resistance, and transparency, PC is used in the manufacturing of medical devices such as syringes, dialyzers, and surgical instruments.Medical Devices: Due to its heat resistance, chemical resistance, and transparency, PC is used in the manufacturing of medical devices such as syringes, dialyzers, and surgical instruments.Medical Devices: Due to its heat resistance, chemical resistance, and transparency, PC is used in the manufacturing of medical devices such as syringes, dialyzers, and surgical instruments.Diagnostic Equipment: Polycarbonate is used for making transparent parts of some diagnostic equipment, such as lenses and cover glasses for optical microscopes.Diagnostic Equipment: Polycarbonate is used for making transparent parts of some diagnostic equipment, such as lenses and cover glasses for optical microscopes.Diagnostic Equipment: Polycarbonate is used for making transparent parts of some diagnostic equipment, such as lenses and cover glasses for optical microscopes.Artificial Organs: The biocompatibility of PC makes it one of the ideal materials for artificial organs (such as heart valves, artificial blood vessels).Artificial Organs: The biocompatibility of PC makes it one of the ideal materials for artificial organs (such as heart valves, artificial blood vessels).Artificial Organs: The biocompatibility of PC makes it one of the ideal materials for artificial organs (such as heart valves, artificial blood vessels).Drug Delivery Systems: Polycarbonate is used in the design and manufacture of drug delivery systems, such as capsules and implants for controlled-release drugs.Drug Delivery Systems: Polycarbonate is used in the design and manufacture of drug delivery systems, such as capsules and implants for controlled-release drugs.Drug Delivery Systems: Polycarbonate is used in the design and manufacture of drug delivery systems, such as capsules and implants for controlled-release drugs.Housings and Protective Covers for Medical Equipment: The impact resistance and transparency of PC make it suitable for manufacturing housings and protective covers for medical equipment.Housings and Protective Covers for Medical Equipment: The impact resistance and transparency of PC make it suitable for manufacturing housings and protective covers for medical equipment.Housings and Protective Covers for Medical Equipment: The impact resistance and transparency of PC make it suitable for manufacturing housings and protective covers for medical equipment. 04Teijin | Medical Grade PC04Teijin | Medical Grade PC04Teijin | Medical Grade PC0404040404040404Teijin | Medical Grade PCTeijin | Medical Grade PCTeijin | Medical Grade PCTeijin | Medical Grade PCTeijin | Medical Grade PCTeijin | Medical Grade PCTeijin's medical-grade transparent PC, while maintaining the transparency and impact resistance of general PCs, is a series of products that also endow materials with properties such as resistance to gamma rays, electron beam sterilization, and steam sterilization. This makes it suitable for various medical device applications.Teijin's medical-grade transparent PC, while maintaining the transparency and impact resistance of general PCs, is a series of products that also endow materials with properties such as resistance to gamma rays, electron beam sterilization, and steam sterilization. This makes it suitable for various medical device applications.FeaturesBiocompatible materials have passed the biocompatibility tests according to ISO10993.A variety of products with different flowabilities are available.FeaturesBiocompatible materials have passed the biocompatibility tests according to ISO10993.A variety of products with different flowabilities are available.FeaturesFeaturesFeaturesFeaturesBiocompatible materials have passed the biocompatibility test of ISO10993.Biocompatible materials have passed the biocompatibility test of ISO10993.Biocompatible materials have passed the biocompatibility test of ISO10993.Biocompatible materials have passed the biocompatibility test of ISO10993.A variety of products with different fluidities are available for selection.A variety of products with different fluidities are available for selection.A variety of products with different fluidities are available for selection.A variety of products with different fluidities are available for selection.Gamma Ray and Electron Beam Sterilization SpecificationsGamma Ray and Electron Beam Sterilization SpecificationsGamma Ray and Electron Beam Sterilization SpecificationsGamma Ray and Electron Beam Sterilization SpecificationsGamma Ray and Electron Beam Sterilization SpecificationsThe MD-12 series. Compared to general PC and similar products on the market, after treatment with γ-rays and electron beams, the MD-12 series exhibits minimal color phase changes, maintaining good color stability, making it suitable for use in applications requiring γ-ray and electron beam sterilization.The MD-12 series. Compared to general PC and similar products on the market, after treatment with γ-rays and electron beams, the MD-12 series exhibits minimal color phase changes, maintaining good color stability, making it suitable for use in applications requiring γ-ray and electron beam sterilization.Steam Sterilization SpecificationsSteam sterilization resistance specificationsSteam sterilization resistance specificationsSteam sterilization resistance specificationsSteam sterilization resistance specificationsMD-22 Series. Compared to the existing competitive steam resistance specifications, the MD-22 series can maintain good transparency after steam treatment.MD-22 Series. Compared to the existing competitive steam resistance specifications, the MD-22 series can maintain good transparency after steam treatment.Fat-resistant emulsion specificationFat-resistant emulsion specificationFat-resistant emulsion specificationFat-resistant emulsion specificationFat-resistant emulsion specificationCompared to general PC, the MD-12 series has "suppression of color changes caused by v-rays and electron beam irradiation" and "extremely high resistance to fat emulsions," making it very suitable for medical consumables (especially in areas prone to stress)    

Total hip arthroplasty (THA) is one of the most successful orthopedic surgeries, bringing immeasurable benefits to patients with hip diseases around the world[1]. However, the biggest obstacle for patients with hip diseases on the road to recovery is postoperative complications, among which aseptic loosening is one of the main reasons leading to revision surgery. Early studies found that the wear rate of traditional ultra-high molecular weight polyethylene liners would directly lead to aseptic loosening of the prosthesis, thus advancing the time for revision surgery[2]. To overcome the shortcomings of ultra-high molecular weight polyethylene, scientists discovered highly cross-linked polyethylene (HXLPE) at the end of the 1990s[3], but new problems arose: the manufacturing process of HXLPE liners during sterilization and irradiation produces free radicals[4]. Free radicals can damage the internal polymer structure of the liner and accelerate oxidation. As research progressed, it was found that vitamin E is a good antioxidant that can block the oxidative chain reaction of free radicals, specifically improving the processing drawbacks of HXLPE[5-6]. Total hip arthroplasty (THA) is one of the most successful orthopedic surgeries, bringing immeasurable benefits to patients with hip diseases around the world[1][1]. However, the biggest obstacle for patients with hip diseases on the road to recovery is postoperative complications, among which aseptic loosening is one of the main reasons leading to revision surgery. Early studies found that the wear rate of traditional ultra-high molecular weight polyethylene liners would directly lead to aseptic loosening of the prosthesis, thus advancing the time for revision surgery[2][2]. To overcome the shortcomings of ultra-high molecular weight polyethylene, scientists discovered highly cross-linked polyethylene (HXLPE) at the end of the 1990s[3][3], but new problems arose: the manufacturing process of HXLPE liners during sterilization and irradiation produces free radicals[4][4]. Free radicals can damage the internal polymer structure of the liner and accelerate oxidation. As research progressed, it was found that vitamin E is a good antioxidant that can block the oxidative chain reaction of free radicals, specifically improving the processing drawbacks of HXLPE[5-6][5-6].E. Oral, S's in vitro study showed that infusing vitamin E into HXLPE not only reduces the wear rate but also eliminates free radicals generated by irradiation[7]. The report content is summarized as follows: two groups of test samples (vitamin E-infused highly cross-linked ultra-high molecular weight polyethylene and traditional ultra-high molecular weight polyethylene) were subjected to wear performance studies after gamma-ray irradiation sterilization. After five million cycles simulating gait, the average wear rate of the 28 mm traditional ultra-high molecular weight polyethylene acetabular cup was 9.54±0.73 mg/Mc (adjusted for fluid absorption), while the average wear rates of the 28 mm and 36 mm vitamin E-infused highly cross-linked ultra-high molecular weight polyethylene acetabular cups were 0.78±0.28 and 0.97±0.49 mg/Mc, respectively, which is a 10-fold reduction compared to the traditional ultra-high molecular weight polyethylene acetabular cup.E. Oral, S's in vitro study showed that infusing vitamin E into HXLPE not only reduces the wear rate but also eliminates free radicals generated by irradiation[7][7]The research report content is summarized as follows: two sets of test samples (highly cross-linked ultra-high molecular weight polyethylene containing vitamin E and conventional ultra-high molecular weight polyethylene) were subjected to wear performance studies after gamma-ray irradiation sterilization. After five million cycles of simulated gait, the average wear rate of 28 mm conventional ultra-high molecular weight polyethylene acetabular liners was 9.54±0.73 mg/Mc (after fluid absorption calibration), while for 28 mm and 36 mm highly cross-linked ultra-high molecular weight polyethylene acetabular liners containing vitamin E, the average wear rates were 0.78±0.28 and 0.97±0.49 mg/Mc, respectively, a reduction by a factor of 10 compared to conventional ultra-high molecular weight polyethylene acetabular liners.Compared with laboratory data, the actual performance of highly cross-linked ultra-high molecular weight polyethylene acetabular liners containing vitamin E in clinical use is not so pronounced. Joost H J van Erp compiled the results of a two-year clinical trial for both materials' acetabular components[8]. This randomized controlled trial included 199 patients, with 102 patients receiving the highly cross-linked ultra-high molecular weight polyethylene acetabular liner containing vitamin E, and 97 patients receiving the conventional ultra-high molecular weight polyethylene acetabular liner. The observation points were preoperative, 3 months postoperative, 12 months postoperative, and 24 months postoperative, using the mean linear head penetration rate (FHP) to compare wear rates through the collection of clinical and radiological parameters. Of these 199 patients, 188 (94%) completed a 2-year follow-up. The FHP for the group with the highly cross-linked ultra-high molecular weight polyethylene liner containing vitamin E was 0.046 mm/year, whereas for the control group with the conventional ultra-high molecular weight polyethylene liner, it was 0.056 mm/year. The researcher then continued the follow-up observations, obtaining 6-year clinical trial follow-up data[9]. The data showed that 173 patients (87%) completed a 6-year follow-up. For the group with the highly cross-linked ultra-high molecular weight polyethylene liner containing vitamin E, the FHP was 0.028 mm/year, and for the control group with the conventional ultra-high molecular weight polyethylene liner, it was 0.035 mm/year. During the follow-up period, no adverse reactions related to the clinical application of highly cross-linked ultra-high molecular weight polyethylene containing vitamin E occurred, and the 6-year revision survival rate for both acetabular liners was 98%, with no cases of aseptic loosening. Goulven Rochcongar's 5-year follow-up data also showed similar results[10]. Five years postoperatively, the FHP for the group with the highly cross-linked ultra-high molecular weight polyethylene liner containing vitamin E was 0.02 mm/year, and for the conventional ultra-high molecular weight polyethylene liner group, it was 0.06 mm/year. Both studies demonstrated the clinical performance of highly cross-linked ultra-high molecular weight polyethylene containing vitamin E, showing a certain degree of reduction in wear in terms of FHP compared to conventional ultra-high molecular weight polyethylene liners.Compared with laboratory data, the actual performance of highly cross-linked ultra-high molecular weight polyethylene acetabular liners containing vitamin E in clinical use is not so pronounced. Joost H J van Erp compiled the results of a two-year clinical trial for both materials' acetabular components[8][8]. This randomized controlled trial included a total of 199 patients, with 102 patients in the vitamin E-infused highly cross-linked ultra-high molecular weight polyethylene (UHMWPE) acetabular liner group and 97 patients in the conventional UHMWPE acetabular liner group. The observation points were pre-operation, 3 months, 12 months, and 24 months post-operation, where clinical and radiological parameters were collected to compare wear rates using the mean linear femoral head penetration (FHP). Among these 199 patients, 188 patients (94%) completed the 2-year follow-up. The FHP for the vitamin E-infused highly cross-linked UHMWPE liner group was 0.046 mm/year, while the FHP for the control group, which used conventional UHMWPE liners, was 0.056 mm/year. The researchers then continued their follow-up observations, obtaining 6-year clinical trial follow-up data[9][9]. The data showed that 173 patients (87%) completed the 6-year follow-up. For the vitamin E-infused highly cross-linked UHMWPE liner group, the FHP was 0.028 mm/year, and for the conventional UHMWPE liner group, it was 0.035 mm/year. During the follow-up period, there were no adverse reactions related to the clinical application of vitamin E-infused highly cross-linked UHMWPE, and the 6-year revision survival rate for both types of acetabular liners was 98%, with no cases of aseptic loosening. Goulven Rochcongar's 5-year follow-up data also showed similar results[10][10]. Five years after surgery, the FHP for the vitamin E-infused highly cross-linked UHMWPE liner group was 0.02 mm/year, while for the conventional UHMWPE liner group, it was 0.06 mm/year. These two studies both demonstrated that, compared to conventional UHMWPE liners, the vitamin E-infused highly cross-linked UHMWPE group had a certain degree of reduction in wear as measured by FHP.The above clinical data are all comparisons of wear between vitamin E-infused highly cross-linked UHMWPE and conventional UHMWPE. Compared to conventional UHMWPE materials, highly cross-linked UHMWPE is also favored by doctors due to its lower wear rate. Bergvinsson H's research data compared the clinical wear performance of these two types of highly cross-linked polyethylenes[11].The above clinical data are all comparisons of wear between vitamin E-infused highly cross-linked UHMWPE and conventional UHMWPE. Compared to conventional UHMWPE materials, highly cross-linked UHMWPE is also favored by doctors due to its lower wear rate. Bergvinsson H's research data compared the clinical wear performance of these two types of highly cross-linked polyethylenes[11][11].The study included a total of 94 patients, with 43 patients in the highly crosslinked ultra-high molecular weight polyethylene group and 51 patients in the vitamin E-containing highly crosslinked ultra-high molecular weight polyethylene group. Analysis software was used to analyze X-rays taken immediately after surgery, one year post-surgery, and five years post-surgery. The results showed no significant difference in wear rates between the two materials (highly crosslinked ultra-high molecular weight polyethylene: 23.2 μm/year, vitamin E-containing highly crosslinked ultra-high molecular weight polyethylene: 24.0 μm/year, p = 0.73). Due to the very small difference in wear rates, it is difficult to predict whether clinical differences will be found in future follow-ups; therefore, longer-term follow-up is needed to continue assessing the clinical differences between vitamin E-containing highly crosslinked ultra-high molecular weight polyethylene acetabular liners and highly crosslinked ultra-high molecular weight polyethylene.References:[1] J. Katz, K. Arant, and R. J. J. Loeser, “Diagnosis and treatment of hip and knee osteoarthritis: a review,” JAMA, vol. 325, no. 6, pp. 568–578, 2021.[2] A. Forster, Z. Tsinas, and M. J. P. Al-Sheikhly, “Effect of irradiation and detection of long-lived polyenyl radicals in highly crystalline ultra-high molar mass polyethylene (UHMMPE) fibers,” Polymers, vol. 11, no. 5, p. 924, 2019.[2] A. Forster, Z. Tsinas, and M. J. P. Al-Sheikhly, “Effect of irradiation and detection of long-lived polyenyl radicals in highly crystalline ultra-high molar mass polyethylene (UHMMPE) fibers,” Polymers, vol. 11, no. 5, p. 924, 2019.[3] S. Kurtz, H. Gawel, and J. D. Patel, “History and systematic review of wear and osteolysis outcomes for first-generation highly crosslinked polyethylene,” Clinical Orthopaedics and Related Research, vol. 469, no. 8, pp. 2262–2277, 2011.[3] S. Kurtz, H. Gawel, and J. D. Patel, “History and systematic review of wear and osteolysis outcomes for first-generation highly crosslinked polyethylene,” Clinical Orthopaedics and Related Research, vol. 469, no. 8, pp. 2262–2277, 2011.[4] E. Oral and O. K. Muratoglu, “Vitamin E diffused, highly crosslinked UHMWPE: a review,” International Orthopaedics, vol. 35, no. 2, pp. 215–223, 2011.[4] E. Oral and O. K. Muratoglu, “Vitamin E diffused, highly crosslinked UHMWPE: a review,” International Orthopaedics, vol. 35, no. 2, pp. 215–223, 2011.[5] B. Currier, J. Currier, M. Mayor, K. Lyford, J. Collier, and D. W. van Citters, “Evaluation of oxidation and fatigue damage of retrieved crossfire polyethylene acetabular cups,” The Journal of Bone Joint Surgery, vol. 89, no. 9, pp. 2023–2029, 2007.[5] B. Currier, J. Currier, M. Mayor, K. Lyford, J. Collier, and D. W. van Citters, “Evaluation of oxidation and fatigue damage of retrieved crossfire polyethylene acetabular cups,” The Journal of Bone & Joint Surgery, vol. 89, no. 9, pp. 2023–2029, 2007.[6] E. Oral, K. Wannomae, S. Rowell, and O. J. B. Muratoglu, “Diffusion of vitamin E in ultra-high molecular weight polyethylene,” Biomaterials, vol. 28, no. 35, pp. 5225–5237, 2007.[6] E. Oral, K. Wannomae, S. Rowell, and O. J. B. Muratoglu, “Diffusion of vitamin E in ultra-high molecular weight polyethylene,” Biomaterials, vol. 28, no. 35, pp. 5225–5237, 2007.[7] E. Oral, S. Christensen, A. Malhi, K. Wannomae, and O. K. Muratoglu, “Wear Resistance and Mechanical Properties of Highly Cross-linked, Ultrahigh- Molecular Weight Polyethylene Doped With Vitamin E,” The Journal of Arthroplasty, vol. 21, no. 4, pp. 580–591, 2006.[7] E. Oral, S. Christensen, A. Malhi, K. Wannomae, and O. K. Muratoglu, “Wear Resistance and Mechanical Properties of Highly Cross-linked, Ultrahigh- Molecular Weight Polyethylene Doped With Vitamin E,” The Journal of Arthroplasty, vol. 21, no. 4, pp. 580–591, 2006.[8] Joost H J van Erp, Julie R A Massier, Jelle J Halma, Thom E Snijders Arthur de Gast (2020) 2-year results of an RCT of 2 uncemented isoelastic monoblock acetabular components: lower wear rate with vitamin E blended highly cross-linked polyethylene compared to ultra-high molecular weight polyethylene, Acta Orthopaedica, 91:3, 254-259, DOI: 10.1080/17453674.2020.1730073[8] Joost H J van Erp, Julie R A Massier, Jelle J Halma, Thom E Snijders & Arthur de Gast (2020) 2-year results of an RCT of 2 uncemented isoelastic monoblock acetabular components: lower wear rate with vitamin E blended highly cross-linked polyethylene compared to ultra-high molecular weight polyethylene, Acta Orthopaedica, 91:3, 254-259, DOI: 10.1080/17453674.2020.1730073[9] Julie R A Massier, Joost H J Van Erp, Thom E Snijders & Arthur DE Gast (2020) A vitamin E blended highly cross-linked polyethylene acetabular cup results in less wear: 6-year results of a randomized controlled trial in 199 patients, Acta Orthopaedica, 91:6, 705-710, DOI: 10.1080/17453674.2020.1807220[9] Julie R A Massier, Joost H J Van Erp, Thom E Snijders & Arthur DE Gast (2020) A vitamin E blended highly cross-linked polyethylene acetabular cup results in less wear: 6-year results of a randomized controlled trial in 199 patients, Acta Orthopaedica, 91:6, 705-710, DOI: 10.1080/17453674.2020.1807220[10] Goulven Rochcongar, Matthieu Remazeilles, Emeline Bourroux, Julien Dunet, Valentin Chapus, Matthieu Feron, César Praz, Geoffrey Buia & Christophe Hulet (2021) Reduced wear in vitamin E-infused highly cross-linked polyethylene cups: 5-year results of a randomized controlled trial, Acta Orthopaedica, 92:2, 151-155, DOI: 10.1080/17453674.2020.1852785 It appears that the provided text is already in English, so no translation was needed for the content. The HTML tags and URLs have been kept as they were. If you intended to provide a different piece of text for translation or if there's anything else I can assist with, please let me know![10] Goulven Rochcongar, Matthieu Remazeilles, Emeline Bourroux, Julien Dunet, Valentin Chapus, Matthieu Feron, César Praz, Geoffrey Buia & Christophe Hulet (2021) Reduced wear in vitamin E-infused highly cross-linked polyethylene cups: 5-year results of a randomized controlled trial, Acta Orthopaedica, 92:2, 151-155, DOI: 10.1080/17453674.2020.1852785[11] Bergvinsson H, Zampelis V, Sundberg M, Tjörnstrand J, Flivik G. Vitamin E infused highly cross-linked cemented cups in total hip arthroplasty show good wear pattern and stabilize satisfactorily: a randomized, controlled RSA trial with 5-year follow-up. Acta Orthop. 2022 Jan 20;93:249-255. doi: 10.2340/17453674.2022.1517. PMID: 35048993; PMCID: PMC8788680.[11] Bergvinsson H, Zampelis V, Sundberg M, Tjörnstrand J, Flivik G. Vitamin E infused highly cross-linked cemented cups in total hip arthroplasty show good wear pattern and stabilize satisfactorily: a randomized, controlled RSA trial with 5-year follow-up. Acta Orthop. 2022 Jan 20;93:249-255. doi: 10.2340/17453674.2022.1517. PMID: 35048993; PMCID: PMC8788680.