自体骨髓间充质干细胞复合β-磷酸三钙修复犬下颌骨节段缺损

Repair of canine segmental mandibular defects by using autogenous bone marrow stromal cells andβ-tricalcium phosphate

目的探讨骨髓间充质干细胞(BMSCs)复合β-磷酸三钙(β-TCP)构建的组织工程骨修复犬下颌骨节段缺损的可行性方法体外成骨诱导犬BMSCs,将第2代细胞复合β- TCP后修复6只犬右侧3cm的下颌骨节段缺损；6只犬以单纯β-TCP植入作为对照,术后4,12,26,32周分别通过影像学、大体形态、组织学和生物力学检测判断骨缺损的修复效果。结果诱导后第2代细胞已具成骨活性。4～26周X线片示实验组新骨形成增加,密度增高,对照组则材料吸收形成明显阴影区,只有少量骨痂。32周实验组骨愈合良好,有较多板层骨；对照组为纤维性愈合骨不连,骨密度检测实验组显著高于对照组。实验组力学强度与正常下颌骨差异无统计学意义。结论自体成骨诱导BMSCs复合β-TCP形成的织工程骨可良好修复犬下颌骨节段缺损。

Objective To repair segmental mandibular defects with autogenous bone marrow stromal cells （BMSCs） and β-tricalcium phosphate. Methods Isolated BMSCs were in vitro expanded. A 3 cm-long segmental mandibular defect was created at right mandible in 12 canines, of which defects in six canines were repaired with BMSCs and β-tricalcium phosphate （β-TCP） and that in other six cases repaired with β-TCP, which was used as control. The engineered bone was evaluated by X-ray, CT, DXA, gross and histological examination, immunohistochemistry and biomechanical test 4,12,26,32 weeks after operation respectively. Results In induced BMSCs, histochemistry showed AKP activity. Oral X-ray showed obvious callus formation 4-26 weeks after operation in experimental group but minimal bone formation in control group. At 32 weeks after operation, gross observation, X-ray and CT demonstrated well bony-union in experimental group but bony-nonunion in control group. DXA indicated that the bone density of experimental group was significantly higher than that of control group. Biomechanical test revealed no statistical difference upon mechanical strength of mandibula between experimental group and normal group. Conclusions Canine segmental mandibular defects can be well repaired with the tissueengineered bone generated by autogenous osteogenic BMSCs and β-TCP scaffold.