Abstract
Articular cartilage repair remains a challenge in orthopedic surgery, as none of the current clinical therapies can regenerate the functional hyaline cartilage tissue. In this study, we proposed a one-step surgery strategy that uses autologous bone marrow mesenchymal stem cells (MSCs) embedded in type II collagen (Col-II) gels to repair the full thickness chondral defects in minipig models. Briefly, 8 mm full thickness chondral defects were created in both knees separately, one knee received Col-II + MSCs transplantation, while the untreated knee served as control. At 1, 3 and 6 months postoperatively, the animals were sacrificed, regenerated tissue was evaluated by magnetic resonance imaging, macro- and microscopic observation, and histological analysis. Results showed that regenerated tissue in Col-II + MSCs transplantation group exhibited significantly better structure compared with that in control group, in terms of cell distribution, smoothness of surface, adjacent tissue integration, Col-II content, structure of calcified layer and subchondral bone. With the regeneration of hyaline-like cartilage tissue, this one step strategy has the potential to be translated into clinical application.