不同细胞移植修复兔全层关节软骨缺损的比较研究

目的 :比较软骨细胞、骨髓基质细胞及成纤维细胞对全层关节软骨缺损的修复作用。材料和方法 :取幼兔的软骨细胞、骨髓基质细胞及成纤维细胞 ,共 3种有生成软骨潜力的细胞进行体外分离培养 ;以聚乳酸 (PLA)为载体 ,将培养的原代细胞植入PLA支架上 ,形成细胞 -PLA复合物。于 2 8只成年新西兰大白兔的股骨滑车关节面上造成直径 4 5mm、深 3 0mm的全层关节软骨缺损 ,将 3种细胞 -PLA复合物分别植入关节软骨缺损处。植入细胞 -PLA复合物为实验组 ,单纯植入PLA支架为对照组。术后 6周、12周观察缺损修复情况及新生组织类型。结果 :软骨细胞移植组为软骨样组织修复 ,分界明显 ,甲苯胺兰及Ⅱ型胶原染色阳性 ;软骨下骨部分重建 ;细胞排列紊乱。骨髓基质细胞移植组为软骨样组织修复 ,分界不明显 ,甲苯胺兰及Ⅱ型胶原染色阳性 ;软骨下骨重建良好 ,软骨下潮线恢复 ;细胞排列趋于正常。成纤维细胞移植组为纤维组织修复 ,甲苯胺兰及Ⅱ型胶原染色阴性 ;软骨下潮线消失。对照组为纤维组织修复。结论 :软骨细胞、骨髓基质细胞移植修复软骨缺损明显优于成纤维细胞及对照组。骨髓基质细胞与软骨细胞移植组的修复结果无统计学差异 ,但骨髓基质细胞修复组织的细胞排列有序 ,软骨下骨重建良好 ,与周围组织融合密切 ,更接近正?

Repair of Full-thickness Articular Cartilage Defects with Different Origins of Cells in A Rabbit Model

Articular cartilage repair remains a clinical and scientific challenge with increasing interest focused on the transplantation of chondrogenic cells. The objective of this study was to evaluate reparative tissues formed in full-thickness articular cartilage defects in an adult rabbit model implanted with three kinds of cultured chondrogenic cells seeded in PLA (polyactic acid) matrices. The three kinds of cultured chondrogenic cells were articular chondrocytes, MSCs (mesenchymal stem cells) and fibroblasts respectively. Materials and methods: Full-thickness articular cartilage defects (4.5mm in diameter and 3mm in depth) were produced in trochlea grooves of both knees of 28 adult New Zealand White rabbits. Chondrocytes, MSCs, and fibroblasts were isolated from the 6-week-old New Zealand rabbits. These three kinds of cells were cultured in vitro and embedded in PLA matrices. Total four groups were made according to the implanted cell type: Group A, chondrocytes; Group B, MSCs; Group C, fibroblasts; Group D; control group (PLA alone). These cell-PLA composites were transplanted into the cartilage defects. The repair tissue was evaluated grossly, histologically, biochemically and by a semiquantitative scoring system at 6 weeks and 12 weeks after implantation. Results: In the group of chondrocytes transplantation (Group A), the defects were repaired with hyaline-like cartilage, which was positive for typeⅡcollagen and toluidine blue staining. The repair tissues maintained their thickness to the full depth of the original defects. The subchondral bone was partly remodeled. A clear gap was seen between reparative and original cartilage. In the group of MSCs transplantation (Group B), the defects were repaired with hyaline-like cartilage, which was positive for typeⅡcollagen and toluidine blue staining. The repair tissues in the defects were thinner than the adjacent normal cartilage. The subchondral bone and tidemark were well remodeled. The repair tissue was well-differentiated into nearly normal morphology of cartilage. There was no obvious boundary between reparative and original cartilage. In the group of fibroblasts transplantation (Group C), the defects were repaired with fibrous tissue, which was negative for typeⅡcollagen and toluidine blue staining. The tidemark was not seen. In the control group of PLA alone, the defects were repaired with fibrous tissue or only limited repair, which was negative for typeⅡcollagen and toluidine blue staining. The surrounding cartilage showed severe degenerative changes. Conclusions: Full-thickness articular cartilage defects treated with chondrocytes or MSCs transplantation were repaired with hyaline-like cartilage tissues and were significantly better than the repair tissues treated with fibroblasts and the control group (PLA alone). Although there were no significant differences in group A and group B, the repair tissues treated with MSCs transplantation had better differentiated cells, better remodeled subchondral bone and better integration with the adjacent cartilage. However a small portion of repair tissues showed degenerative changes at 12 weeks after chondrocytes or MSCs transplantation.