组织工程骺板软骨移植修复兔胫骨上骺板缺损

REPAIR OF UPPER TIBIAL EPIPHYSEAL DEFECT WITH ENGINEERED EPIPHYSEAL CARTILAGE IN RABBITS

目的 探讨在体外以三维支架构建的组织工程骺板软骨修复胫骨上骺板缺损的效果 ,了解促进植入工程化软骨与受区骺板融合方法的效果。 方法 酶消化分离幼兔骺板软骨细胞并接种培养 ,收获第 1代软骨细胞 ,制成 2 .5× 10 7/ ml的细胞凝胶混悬液 ,接种于聚磷酸钙纤维 / L-聚乳酸 (CPPf/ PL L A)复合支架体外构建组织工程化软骨。采用幼兔右侧胫骨上骺板 4 0 %缺损模型 ,将日本大耳白兔 72只分为 4组 ,每组 18只 :A组缺损区植入同窝幼兔来源的工程化软骨 ,并以相同的细胞凝胶混悬液充填其间隙 ;B组充填复合有生物凝胶而无细胞的 CPPf/ PL L A支架材料 ;C组植入皮下脂肪 ;D组不做任何充填。分别于术后 2、4、6、8、12和 16周摄 X线片、大体及组织学观察。 结果 A组术后2周组织工程化软骨在骺板缺损区即衍生为典型的骺板组织结构 ,并与受区骺板组织很好融合 ;4周修复骺板组织 ,结构正常、胫骨无畸形 ;8周后骺板修复区出现早闭的组织学表现 ,胫骨出现短缩和内翻畸形 ;16周修复区骺板已闭合 ,胫骨畸形明显 ,生长功能恢复率为 4 3.6 %。B、C、D3组术后 2周胫骨即出现畸形 ;4周骺板缺损区均已骨性闭合 ,畸形明显 ;16周畸形严重。后三组间差异无统计学意义 ,骺板缺损区无骨生长。 结论 组织工程化的骺板软骨?

Objective To observe the effect of engineered epiphyseal cartilage regenerated in vitro with 3-D scaffold by chondrocytes from epiphyseal plate in repairing the tibial epiphyseal defect, and to explore the methods to promote the confluence between engineered cartilage and epiphyseal plate. Methods Chondrocytes were isolated enzymatically from the epiphyseal plates of immature rabbits, and then planted into the tissue culture flasks and cultivated. The first passage chondrocytes were collected and mixed fully with the self-made liquid biological gel at approximately 2.5×10 7cells/ml to form cell-gel fluid. The cell-gel fluid was dropped into the porous calcium polyphosphate fiber/poly-L-lactic acid(CPPf/PLLA)scaffold, and a cell-gel-scaffold complex formed after being solidified. The defect models of 40% upper tibial epiphyseal plate were made in 72 immature rabbits; they were divided into 4 groups: group A(the cell-gel-scaffold complex was transplanted into the defect and the gap filled with chondrocyte-gel fluid), group B (with non-cell CPPf/PLLA scaffold), group C(with fat) and group D(with nothing). The changes of roentgenograph, gross and histology were investigated after 2, 4, 6, 8, 12 and 16 weeks of operation. Results In group A, the typical histological structure of epiphyseal plate derived from the engineered cartilage with a fine integration between host and donor tissues after 2 weeks. The repaired epiphyseal plate had normal histological structure without deformation of tibia after 4 weeks. The early histological change of epiphyseal closure appeared in the repaired area with varus and shortening deformation of the tibia after 8 weeks. The epiphyseal plate was closed in the repaired area with more evident deformation of tibia; the growth function of repaired epiphyseal plate was 43.6% of the normal one. In groups B, C and D, deformation of tibia occurred after 2 weeks; the defect area of epiphyseal plate was completely closed after 4 weeks. The deformation was very severe without growth of the injured epiphyseal plate after 16 weeks, and no significant difference was observed between the three groups. Conclusion Engineered epiphyseal cartilage can repair the epiphyseal defect in the histological structure with partial recovery of the epiphyseal growth capability. Injecting the suspension of fluid chondrocyte-gel into the defects induces a fine integration of host and donor tissues.