FTY720-P联合同种异体骨移植修复兔桡骨大段骨缺损的实验研究

Experimental study of FTY720-P combined with allogeneic bone transplantation for repairing rabbit segmental long bone defects

目的探索FTY720-P联合同种异体骨移植修复兔桡骨大段骨缺损的效果。方法 36只新西兰大白兔右侧桡骨中段建立15mm骨缺损模型后随机分为3组,A组移植FTY720-P溶液浸泡后的同种异体骨,B组移植未做处理的同种异体骨,C组移植自体桡骨。术后4、8、12周通过影像学检查,组织学、免疫组织化学检测及三点弯曲实验评估骨缺损修复效果。结果术后12周,A、C组移植骨与宿主骨达到骨性愈合。术后4、8、12周A、C组骨缺损区域骨痂形成量多于B组,并且A、C组Lane-Sandhu评分均高于B组,差异有统计学意义(P<0.05),而A、C组间Lane-Sandhu评分比较,差异无统计学意义(P>0.05)。组织学检查显示,术后4周B组移植骨周围见较多炎性细胞,而A组炎性细胞少见;术后8周A组移植骨内新生血管生成。术后4周各组内源性骨形态发生蛋白-2(BMP-2)在新生成骨质的骨陷窝、新生骨附近成骨细胞细胞质及纤维性骨痂基质内呈强阳性表达。三点弯曲实验显示,A组修复后的桡骨最大弯曲强度大于B组(P<0.05),与C组比较,差异无统计学意义(P>0.05)。结论 FTY720-P联合同种异体骨能较好地修复兔桡骨大段骨缺损,且达到与自体骨修复相当的效果。

Objective To explore the effect of FTY720-P in combination with allogeneic bone grafting on repairing rabbit segmental long bone defects.Methods A total of 36 New Zealand white rabbits were divided into 3 groups after the establishment of the right radius defect model(15 mm in length).Defects were repaired with allogeneic bones which had soaked in FTY720-P solution in group A,with allogeneic bones in group B,with autogenous radiuses in group C,respectively.The repair effect of bone defects were evaluated by radiographic,histological,immunohistochemical and biomechanical examinations at 4,8,12 weeks after operation.Results At 12 weeks after operation,the bone grafts were completely integrated with the cut ends of the host bone in group A and group C.At 4,8,and 12 weeks after operation,the amounts of callus formation in the bone defect areas of group A and group C were higher than that of group B,and the Lane-Sandhu scores of group A and gr oup C were higher than that of group B,there were statistically significant differences(P<0.05).However,there was no significant difference of Lane-Sandhu score between group A and group C(P>0.05).The histological examination showed that more inflammatory cells were observed around the bone graft in group B than those in group A at 4 weeks after operation,and newly formed vessels were observed in group A at 8 weeks after operation.Endogenic BMP-2 were mainly expressed in the bone lacunae of newly formed bones,the osteoblasts cytoplasm,and the matrix of fibrous callus nearing newly formed bones in each groups at 4 weeks after operation.The maximum bending strength of the implanted radiuses assessed by three-point bending test in group A were significantly stronger than that in group B(P<0.05),while no significant difference was found compared to group C(P>0.05).Conclusion FTY720-P in combination with allogeneic bone by soaking could better repair critical-size bone defects in rabbit,and achieve the same effect as the autogenous bone graft.