骨髓间充质干细胞移植促进大鼠下颌骨牵张成骨的实验研究

目的:探讨大鼠下颌骨牵张间隙内移植自体骨髓间充质干细胞,促进骨痂形成的可行性。方法:选用54只雄性SD大鼠,密度梯度离心法分离骨髓间充质干细胞(MSCs)。所有大鼠行右侧下颌骨牵张;并于术后随机分为试验和对照2组。牵张结束时,实验组牵张间隙内注射自体MSCs;而对照组只注射等量生理盐水。分别于固定期第2、4、8周分3批处死大鼠,进行放射学、组织学观察,并对骨组织形态计量学参数进行统计学分析(t检验)。结果:放射学和组织学观察表明,2组牵张间隙内均形成了骨痂组织,但实验组新生骨组织显著多于对照组。计量学分析也显示,各时间点实验组新生骨量(NBV1和NBV2)和新生骨小梁宽度(TNT)均显著高于对照组(P<0.01)。结论:牵张间隙内行自体骨髓MSCs移植,可有效促进新骨形成,缩短固定期;该方法对众多的颅颌面外科畸形的矫治极具价值。

Callus stimulation by autologous bone marrow mesenchymal stem cells transplantation in rat mandibular distraction osteogenesis

PURPOSE: The purpose of this study was to explore the feasibility of transplantation with autologous bone marrow mesenchymal stem cells (MSCs) into distraction gap to accelerate new bone formation. METHODS: Bone marrow MSCs were obtained by density gradient centrifugation from the tibiae of 54 male SD rats. The rats underwent right mandibular distraction and then were randomly divided into 2 groups. After distraction was finished, autologous MSCs were transplanted into the distracted gap in the experimental group, while in the control group only normal saline was injected. The distracted mandibles were harvested after 2, 4, and 8 weeks of consolidation and evaluated by radiological, histological and histomorphometric analysis. RESULTS: Radiological and histological examinations showed bone callus formed in both groups at all time points, nevertheless more bone was observed in the experimental group than in the control group. Histomorphometric analysis also demonstrated that both new bone volume (NBV1 and NBV2) and the thickness of new trabeculae (TNT) were significantly higher in the experimental group than in the control group(P<0.01). CONCLUSION: The current study showed that autologous bone marrow MSCs transplantation promoted bone formation in the distracted gap and shortened the consolidation period. Therefore it may be quite valuable in correction of many craniofacial deformities. Supported by National Natural Science Foundation of China (Grant No.30371553)