脉冲电磁场诱导人骨髓间充质干细胞向成骨细胞分化的研究

目的 观察脉冲电磁场(PEMFs)对人骨髓间充质干细胞(hMSCs)向成骨细胞分化的影响。方法 分离并培养hMSCs，取第3代细胞，分为对照组与处理组，处理组细胞接受频率12Hz、场强1．1mT的PEMFs刺激，每日8h；对照组细胞不接受PEMFs刺激。应用透射电镜观察2组细胞超微结构，采用碱性磷酸酶染色、骨钙素免疫组织化学染色、四环素荧光标记等方法进行观测。结果 细胞培养5～6d即可传代，经PEMFs连续刺激3d后，hMSCs细胞形态发生变化，3周后聚集成细胞钙化结节。透射电镜下观察显示：细胞比较成熟，内质网扩张，其碱性磷酸酶染色、骨钙素免疫组织化学染色和四环素荧光标记均为阳性。结论 hMSCs经特定频率和场强的PEMFs体外刺激后，可向成骨细胞分化，符合成骨细胞的形态学和生物学特性，为体外构建组织工程化骨提供自体种子细胞。

The effect of pulsed electromagnetic fields on the cellular differentiation from human mesenchymal stem cells to osteoblast

Objective To observe the effect of pulsed electromagnetic fields (PEMFs) on the cellular differentiation from human mesenchymal stem cells (hMSCs) to osteoblast. Methods We isolated and cultured the hMSCs, then divided the passage three cells into the control group and the treatment group. The treatment group was stimulated by the PEMFs (12Hz pulse burst, 1.1mT peak, 8h/day). Transmission electron micrograph, cytochemical staining for alkaline phosphatase (ALP), cytochemical staining for osteocalcin expression and tetracycline fluorescence label were applied to measure the hMSCs differentiation. Results PEMFs treatment accelerated cellular differentiation significantly, hMSCs could be passed in 6 or 5 days, after 3 days of exposure. The cellular form was changed and they gradually congregated into a mineralized matrix in 3 weeks. A transmission electron micrograph of the third passage MSCs cultured with exposure to PEMFs showed expanded endoplasmic reticulum. Cytochemical staining for ALP and osteocalcin expression and tetracycline fluorescence label were positive. Conclusion PEMFs could accelerate the differentiation of hMSCs to osteoblast, which serves as the autogenous seeding cells for in vitro construction of tissue engineering bone.