Bone tissue regeneration metals

Nanocomposites in orthopedic tissue engineering mimic the complex nanoarchitecture of natural bone, muscle, cartilage, and tendon tissue, providing a novel and practical approach to tissue regeneration. All ceramic, polymer, and metallic matrix nanocomposites offer a wide range of properties with different chemical and mechanical features they also exhibit indispensable bioactivity. There is a great potential to improve current biomaterials and nanocomposite scaffolds for musculoskeletal tissue regeneration. However, the variety of different chemical elements and structures of nanocomposites make it difficult to predict unknown outcomes of exposure to musculoskeletal tissue. More research is clearly needed to fully understand favorable nanocomposite chemistries for musculoskeletal tissue. 

Metallic materials such as stainless steels, Ti and Co-Cr based alloys are currently used as permanent implant materials. These alloys are also used for temporary implant applications in the form of plates, screws and pins, for the repair of bone fracture. However, these metal implants have to be removed by a second surgical proceditre after the tissues have healed sufficiently, since they pose a risk of releasing toxic metalhc ions and/or particles through corrosion or wear processes. The second surgical procedure adds to the cost and bmden to the patients. Identification of implants to support tissue regeneration and healing in specific applications by material corrosion and simultaneous implant replacement by the surroimding tissues is an important area of research. 

Around the movable parts of the artificial joints a new connective tissue capsule is formed. Its structure is roughly similar to that of a normal joint capsule but never identical. The tissue is much coarser as regeneration is accompanied by a foreign body reaction to fragments of metal and plastic as well as to the components of bone cement. 

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