Zdenek Krulis

Hydrogel Scaffolds Contribute to the Osteogenesis and Chondrogenesis in the Small Osteochongral Defects

Hyaline cartilage shows only a limited response to self-repair (Hunter, 1743). Many people are stricken with degenerative osteochondral defects. Modern therapies of osteochondral defects are focused (for example) on the transplantation of osteochondral autografts, rushed spongiosa with collagen, chondrocytes and many others. The insertion of a crushed autologous bone graft has been reported as a possible therapy. However, the regenerative biomechanical (material) quality was less than 70% of healthy cartilage for fragments and controls (Kleemann et al., 2006). The transplantation of autologous osteochondral 3Dcylinders is one of several surgical therapies (Horas, 2003). During operations osteochondral defects are filled with material of a natural histological structure. However, the subchondral bone plates are interrupted and the biomechanical stability between the original tissue and the transplanted tissue is different. Provision of a long-term functional stability of inanimate implants in live surroundings is a complex and quite uneasy task. The development of replacements for a human subchondral bone and articular cartilage follows the path of a proposal and investigation of such materials whose mechanical properties are very similar to the biomechanical properties of a bone/cartilage tissue and whose biophysical and biochemical interactions with the surrounding living tissue neither cause necroses, nor lead to any initiation of other pathological processes. The biophysical and biochemical fixation of replacements and/or scaffolds to the tissue depends dominantly: (a) on the biomechanical properties and biochemical environments of the implants and the tissue; (b) on the stress– strain distributions in the tissue and the replacement, (c) on the organization and stability of