Enhancing Biological and Biomechanical Fixation of Osteochondral Scaffold: A Grand Challenge

Osteoarthritis (OA) is a degenerative joint disease, typified by degradation of cartilage and changes in the subchondral bone, resulting in pain, stiffness and reduced mobility. Current surgical treatments often fail to regenerate hyaline cartilage and result in the formation of fibrocartilage. Tissue engineering approaches have emerged for the repair of cartilage defects and damages to the subchondral bones in the early stage of OA and have shown potential in restoring the joint's function. In this approach, the use of three-dimensional scaffolds (with or without cells) provides support for tissue growth. Commercially available osteochondral (OC) scaffolds have been studied in OA patients for repair and regeneration of OC defects. However, some controversial results are often reported from both clinical trials and animal studies. The objective of this chapter is to report the scaffolds clinical requirements and performance of the currently available OC scaffolds that have been investigated both in animal studies and in clinical trials. The findings have demonstrated the importance of biological and biomechanical fixation of the OC scaffolds in achieving good cartilage fill and improved hyaline cartilage formation. It is concluded that improving cartilage fill, enhancing its integration with host tissues and achieving a strong and stable subchondral bone support for overlying cartilage are still grand challenges for the early treatment of OA

Histochemical Studies of Rheumatic Conditions: I. Observations on the Fine Structures of the Matrix of Normal Bone and Cartilage

Recently, specific enzymes have become available in highly purified form, which will attack the two main constituents of the ground substance of con-nective tissue. Collagenase (from CL. Welchii filtrates, purified by the method of Bidwell and van Heyningen, 1948), attacks collagen but has a negligible action on other proteins. Hyaluronidase (Benger) acts upon the mucopoly-saccharide components, not only those built up from hyaluronic acid as the repeating unit, but also upon chondrin, where the repeating unit is chon-droitin sulphuric acid. Trypsin, on the other hand, will digest the majority of normal proteins, but will not attack collage