骨髓基质干细胞复合I型胶原修复兔膝关节软骨缺损的研究

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

目的探讨骨髓基质干细胞复合I型胶原海绵对兔膝关节浅层大面积软骨缺损的修复作用；观察^3H-TdR对骨髓基质干细胞的示踪作用。方法骨髓基质干细胞复合组织工程支架I型胶原海绵，植入修复兔膝关节大面积浅层软骨缺损模型，分别于术后4、12、24周取材，观察修复效果；运用’H．TdR标记骨髓基质干细胞，同法植入软骨缺损区，分别于术后4、12、16及24周取材，液体闪烁计数定量分析、乳胶封片、4周后显影定性分析。结果实验组术后4周缺损表面未见明显的新生软骨形成；12周，缺损表面有少量的新生软骨形成；24周，缺损表面的新生软骨较4、12周的新生软骨明显，仍存在部分缺损尚未修复。对照组则均未见明显的修复。修复组织的细胞核内均有放射活性，与对照组比较，差异均有统计学意义（P〈0．05），提示修复组织的细胞来源为体外移植的细胞，而非自体细胞，至术后24周，植入的细胞仍然存活。结论该方法对兔膝关节软骨缺损具有修复作用，但不能完全修复；所修复组织的细胞来源为植入的骨髓基质干细胞；’H—TdR标记对骨髓基质干细胞具有较好的长期示踪作用。

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 Isponge, and to track BMSCs labeled by 3 H-TdR. Methods Bone marrow aspi- rate of rabbits was cultured and expanded to the 3rd passage, mixed with human placenta collagen Isponge 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 〈 O. 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 HTdR labeling is a good tracing of implanted BMSCs in long-term observation.