Repairing defects of rabbit large articular cartilage with bone marrow-derived mesenchymal stem cells combined with collagen I

Objective To investigate the feasibility of repairing the whole layer cartilage defects of lateral tibial plateau of rabbits by implanting bone marrow-derived mesenchymal stem cells (BMSCs) and human placenta collagen Ⅰ -sponge,and to track BMSCs labeled by 3 H-TdR.Methods Bone marrow aspirate of rabbits was cultured and expanded to the 3rd passage,mixed with human placenta collagen Ⅰ- sponge and transplanted to the whole layer cartilage defects of adult rabbit in lateral tibial plateau.The repair results were observed after 4,12 and 24 weeks.BMSCs P3 were labeled with 3 H-TdR,and transplanted by using the same method.Results Nearly no obvious neo-cartilage formed 4 weeks after operation,little neo-cartilage formed 12 weeks after operation,more obvious neo-cartilage formed at 24th week than at 4th and 12th week after operation.At 24th week postoperation,the surface was smooth,but partial defects still existed.No obvious repair evidence was found on the surface of the control group.Radioactivity existed in all repair tissue.There was significant difference between experimental group and control group (P ＜0.05).After 24 weeks,the implanted cells were still alive.Conclusion The tissue-engineering cartilage by this method can repair the defects of the whole layer cartilage defects of lateral tibial plateau of rabbits,but it can not repair the defects completely.The resource of the repaired tissue is implanted BMSCs.3 H-TdR labeling is a good tracing of implanted BMSCs in long-term observation. Key words: Bone marrow-derived mesenchymal stem cells;  Collagen Ⅰ;  3H-TdR;  label