目的 研究低频电磁场对组织工程化骨成骨能力的影响及修复兔股骨中段节段性骨缺损的效果.方法 将兔骨髓间充质干细胞(bone mesenchymal stem cells,BMSCs)接种至β-磷酸三钙(beta-tricalcium phosphate,β-TCP)支架上构建组织工程化骨,并连续7 d给予低频电磁场暴磁处理,每天4 h.通过CCK-8法检测暴磁处理后BMSCs/β-TCP复合体内细胞的增殖情况,实时荧光定量PCR分析骨形态发生蛋白2(bone morphogenetic protein 2,BMP2)、骨桥蛋白(osteopontin,OPN)和Runt相关基因2(runt-related transcription factor 2,RUNX2)mRNA的表达,定量检测碱性磷酸酶(alkaline phosphatase,ALP)的活性;制作兔股骨中段节段性骨缺损模型,植入经过暴磁处理的BMSCs/β-TCP复合体,术后4、12周进行X线检查和组织学检测.结果 低频电磁场可以促进组织工程化骨中BMSCs的增殖,暴磁处理后成骨基因BMP2、RUNX2和OPN的表达量明显增加,ALP活性显著增高.动物体内实验结果显示暴磁组的Lane-Sandhu X线评分较对照组明显升高,组织学结果显示暴磁组新骨生成的速度和骨缺损修复效果优于对照组.结论 低频电磁场可提高组织工程化骨的成骨能力,暴磁干预后的组织工程化骨具有较好的骨修复效果.%Objective To explore the effects of low - frequency electromagnetic fields on the osteogenetic ability of tissue-engineered bone and the effect of repairing segmental bone defect of the middle segment of femur in rabbits. Methods Bone mesenchymal stem cells (BMSCs) were seeded on beta tricalcium phosphate (β-TCP) scaffold to construct an engineered bone graft which was exposed with or without low-frequency electromagnetic fields. CCK-8, ALP, and qPCR tests were applied to assess proliferation and differentiation. Rabbit femur segmental bone defect model was established to evaluate the efficacy of the electromagnetic fields exposed engineered construct for osteogenesis. Results The proliferation rate of BMSCs in the engineered bone grafts exposed to electromagnetic fields was increased. Electromagnetic field exposition promoted the gene expression and ALP activity of BMSCs. In vivo study demonstrated increased bone formation was seen in the electromagnetic fields exposed groups. Conclusion Electromagnetic fields exposure can enhance the osteogenic potentials of the engineered BMSCs/β-TCP constructs. The BMSCs/β-TCP constructs exposed to electromagnetic fields can promote in vivo bone regeneration.
展开▼
