慢病毒介导骨形成蛋白-2基因转染骨髓间质干细胞修复大鼠颅骨骨缺损

目的 观察携带人骨形成蛋白-2(hBMP-2)基因的慢病毒(lentivirus)转染骨髓间质干细胞构建的组织工程化骨对大鼠颅骨极量骨缺损的修复效果. 方法 300～350g雄性 SD大鼠取股骨骨髓体外培养扩增骨髓间质干细胞(BMSC),以lentivirus载体介导hBMP-2基因转染BMSC,诱导其向成骨细胞分化.将细胞接种于经纤维连接蛋白修饰的β-磷酸三钙(β-TCP),共同培养10d.30只大鼠均造成颅骨极量缺损(直径8mm)模型,分为Lev- BMP2转染细胞+β-TCP组(A组:n=10);BMSC +β-TCP组(B组:n=10);β-TCP组(C组:n=10)于第4、8、12、20周从影像学及组织学角度观察比较颅骨缺损修复情况.结果 无论X线摄片及组织切片均表明,A组颅骨骨缺损修复优于同期的B组和C组.在各时间点A组和B组在植骨区均有新骨形成,而C组仅见边缘区成骨.术后20周新生骨小梁相对体积(TBV,%)A组为(60.83±11.49),B组为(40.37±9.02),C组为(18.37±6.02),差异有统计学意义(P<0.01). 结论 Lev- BMP2转染BMSC复合β-TCP构建的组织工程化骨对大鼠颅骨极量骨缺损有较好的修复效果.

Repair of critical size rat calvarial defects with bone marrow-derived mesenchymal stem cells transfected by lentiviral vector-mediated hBMP-2 gene (Lev-hBMP-2)

Objective To evaluate osteogenetic effectiveness of lentiviral vector-mediated hBMP-2 gene (Lev-hBMP-2) transfection into bone marrow-derived mesenchymal stem cells (BMSC) mixed with β-TCP in the repair of critical size rat calvarial defects.Methods In 30 male adult SD rats (weighing 300-350 g) bone marrow was obtained from femurs.The BMSC were cultured and transfected by Lev-hBMP-2 in vitro for 14 days.The cells were then seeded and subcultured for another 10 days in β-TCP modified by recombinant human fibronectin.Cell-ceramic compound was used to repair critical size (diameter of 8 mm) calvarial defects in the corresponding rats in the experimental group.The rats were divided into three groups: (1) Lev-hBMP-2 transfected BMSC+β-TCP (group A: n=10);(2) BMSC+β-TCP (group B: n=10);(3) β-TCP (group C: n=10).The skull defect reconstruction was observed histomorphometrically at 4th,8th,12th and 20th week after operation.Results Tissue slicing showed that in the whole defected areas new bone growing could be found during different stages in group A and group B,while osteogenic tissue only appeared in the margin in group C.There was statistically significant difference in the new trabecular bone volume (TBV,%) in groups A (60.83±11.49),B (40.37±9.02) and C (18.37±6.02).Conclusion The tissue-engineered bone made by Lev-hBMP-2 transfected BMSC mixed with β-TCP can repair critical size rat calvarial defects.