Experimental research on repairing full-thickness articular cartilage defects by transplantation of autologous uncultured bone-marrow-derived mononuclear cells in combination with micro-fracture

Abstract

To examine the feasibility of autologous uncultured bone-marrow-derived mononuclear cells (BM-MNCs) in combination with microfracture in a full-thickness articular cartilage defect model so as to provide experimental rationales for clinical applications. A total of 40 rabbits were divided randomly into groups A, B, C and D (n = 10 each). In groups A and C, 5 ml marrow samples were harvested from left femur and then autologous BM-MNCs isolated. The full-thickness articular cartilage defects were made on femoral intercondylar fossa in right knees of rabbits. Group A: micro-fracture was made on cartilage defect and then autologous uncultured BM-MNCs-autologous fibrin gel complex implanted; Group B:the same micro-fracture was made on cartilage defect and autologous fibrin gel implanted; Group C:the cartilage defect was implanted with autologous uncultured BM-MNCs-autologous fibrin gel complex; Group D:the cartilage defect was implanted with autologous fibrin gel. Five rabbits were sacrificed at Weeks 8 and 12 post-transplantation in each group. And the reparative tissue samples evaluated grossly, histologically and immunohistochemically were graded according to the gross and histological scales. The statistical analyses of histological gradings at Weeks 8 and 12 showed that group A was significantly better than groups B, C and D (P < 0.05), groups B and C were better than group D (P < 0.05) and each group at Week 12 was better than itself at Week 6 (P < 0.05). Both of micro-fracture and transplantation of uncultured autologous BM-MNCs plus autologous fiber gel can promote the repair of cartilage defects. The combined use of micro-fracture and autologous uncultured BM-MNCs promotes the regeneration of articular cartilage so that it may provide theoretical rationales for clinical applications.