组织工程骨软骨复合体修复犬膝关节负重区骨软骨缺损的实验研究

Repair of large articular high -;oad-bearing osteochondral defects with extraceHular matrix-derived acellular matrix biphasic scaffold and bone marrow -derived mesenchymal stem cells in a canine model

目的观察以骨软骨支架复合骨髓基质干细胞（bone-marrow mesenchymal stem cells，BMSCs）修复犬膝关节负重区骨软骨缺损的疗效。方法利用软骨细胞外基质作为软骨支架部分，以脱细胞骨作为骨支架部分，采用相分离技术制备骨软骨双相支架，将成软骨诱导的BMSCs种植到双相支架上构建组织工程骨软骨复合体，并以此复合体修复犬膝关节股骨髁负重区骨软骨缺损，分为细胞一双相支架组（实验组）和单纯支架组（对照组），分别在术后3和6个月时取材，根据大体、组织学、Micro—CT等检测结果进行半定量或定量评估。结果大体及组织学评价表明：同一时间点实验组的修复效果优于对照组，且实验组在术后6个月时的修复效果优于其术后3个月时，两项差异均有统计学意义；而对照组不同时间点修复效果的差异无统计学意义。Micro-CT检测结果表明实验组与对照组软骨下骨均得到重建，两者的差异无统计学意义。结论骨软骨双相支架复合成软骨诱导的BMSCs能成功修复犬膝关节负重区的骨软骨缺损，其修复效果明显优于单纯支架植入组。

Objective To develop an extracellular matrix （ECM）-derived, integrated biphasic scaffold, and to investigate the regeneration potential of the scaffold loaded with chondrogenically induced bonemarrow mesenehymal stem cells （BMSCs） in the repair of large, high-load-bearing osteoehondral defects in a canine model. Methods The biphasic scaffolds were fabricated using cartilage ECM-derived Scaffold （Cartilage layer） and acellular bone matrix （Bone layer） by phase separation technique. Articular high-load-beating osteoehondral defects （4.2 mm diameter ×6 mm deep） were created in femoral condyles. The defects were treated with constructs of a biphasic scaffold with chondrogenieally induced BMSCs （experimental group） or cell-free scaffolds （control group）. The repaired defects were evaluated for gross morphology, histological, and micro-CT analysis at 3 and 6 months post-implantation. Results Statistical analysis demonstrated that the gross and histological grading scores of the experimental group were always higher than those of the control group at both time points and that the scores for the 6-month experimental group was significantly higher than 3-month experimental group, while there was no significantly difference in control group between two time points. Micro-CT analysis of the subchondral bone showed mature trabeeular bone regularly formed at both 3 and 6 months, with no significant difference between the experimental and control groups. Conclusion The ECM-derived, integrated biphasic scaffold combined with chondrogenically induced BMSCs has high potential in repair of large, high-load-bearing osteoehondral defects.