Cartilage repair: 2013 Asian update.

Despite financial and regulatory hurdles, Asian scientists and clinicians have made important contributions in the area of cartilage repair. Because it is impossible to include observations on all the published articles in one review, our attempt is to highlight Asian progress in this area during recent years (2005 to the present), reviewing research development and clinical studies. In the former, our discussion of in vitro studies focuses on (1) potential sources of stem cells--such as mesenchymal stem cells (MSCs) from marrow, cord blood, synovium, and mobilized peripheral blood--which are capable of enhancing cartilage repair and (2) the use of growth factors and scaffolds with and without cells. Our discussion of animal studies attempts to summarize activities in evaluating surgical procedures and determining the route of cell administration, as well as studies on matrices and scaffolds. It ranges from the use of small animals such as rats and rabbits to larger animals like pigs and dogs. The local adherent technique, enhancement of microfracture with poly(l-lactic-co-glycolic acid) scaffold, adenovirus-mediated bone morphogenic protein (BMP) genes, and MSCs--whether they are magnetically labeled, suspended in hyaluronic acid, or immobilized with transforming growth factor-β (TGF-β)--have all been able to engineer a repair of the osteochondral defect. Although published Asian reports of clinical studies on cartilage repair are few, the findings of relevant trials are summarized in our discussion of these investigations. There has been a long history of use of laboratory-derived MSCs for cartilage repair. Recent progress has suggested the potential utility of cord blood and mobilized peripheral blood in this area, as well as more injectable bone marrow (BM)-derived stem cells. Finally, we make a few suggestions on the direction of research and development activities and the need for collaborative approaches by regulatory agencies.