Porous Scaffolds for Regeneration of Cartilage, Bone and Osteochondral Tissue.

Porous scaffolds play an important role as a temporary support for accommodation of seeded cells to control their functions and guide regeneration of functional tissues and organs. Various scaffolds have been prepared from biodegradable polymers and calcium phosphate. They have also been hybridized with bioactive factors to control differentiation of stem cells. Except the composition, porous structures of scaffolds are also extremely important for cell adhesion, spatial distribution and tissue regeneration. The method using preprepared ice particulates has been developed to precisely control surface and bulk pore structures of porous scaffolds. This chapter summarizes the design and preparation of porous scaffolds of biodegradable polymers and their hybrid scaffolds with calcium phosphate nanoparticles and bioactive factors. Their applications for regeneration of cartilage, bone and osteochondral tissue will be highlighted. HIGHLIGHTS: Porous scaffolds of naturally derived polymers and their hybrid scaffolds with biodegradable synthetic polymers have been prepared for cartilage tissue engineering. The surface and bulk pore structures of the scaffolds are controlled by using preprepared ice particulates. The scaffolds facilitate cartilage tissue engineering when they are used for three-dimension culture of chondrocytes. PLGA-collagen-BMP4 and collagen-CaP nanoparticles-dexamethasone hybrid scaffolds have been prepared and used for culture of mesenchymal stem cells. The hybrid scaffolds facilitate osteogenic differentiation of mesenchymal stem cells and ectopic bone tissue regeneration during in vitro culture and in vivo implantation. Osteochondral tissue engineering has been realized by laminating two different layers of cartilage and subchondral bone or by using stratified scaffolds for simultaneous regeneration of cartilage and subchondral bone.