脉冲电磁场对大鼠成骨细胞增殖影响的活细胞成像观察研究

The research of pulsed electromagnetic fields influence osteoblasts proliferation of rat by the live cell imaging technology

目的应用活细胞成像技术观察脉冲电磁场作用下大鼠成骨细胞的生长、增殖过程,探讨不同脉冲电磁场强度对大鼠成骨细胞生长、增殖的影响。方法首先采用MTT法检测在15Hz,0.1、0.3、0.5、1.0mT脉冲电磁场连续刺激下,4种脉冲电磁场强度组与对照组的成骨细胞存活与增殖能力,筛选出最佳的脉冲电磁场刺激强度。根据筛选结果,选用频率15Hz、强度0.1mT的脉冲电磁场,应用活细胞成像技术,以Time-Lapse方式,对脉冲电磁场刺激组与对照组成骨细胞的生长、增殖过程,作多点平行对照记录,动态观察两组成骨细胞的贴壁速率与分裂速率。并采用MTT法同步检测两组细胞的增殖情况。结果原代培养3d的成骨细胞,在15Hz脉冲电磁场中连续刺激3d,经MTT法检测,1.0mT组细胞几乎全部死亡,0.5mT组与对照组比较细胞增殖能力无明显差别,0.3、0.1mT组与对照组比较细胞增殖能力增强(P<0.05、P<0.01)。活细胞成像Time-Lapse平行对照记录,动态观察分析表明,15Hz、0.1mT脉冲电磁场组观察野的细胞贴壁速率与对照组比较无明显差别,分裂速率较对照组观察野增快(P<0.05),MTT法同步检测也证明0.1mT脉冲电磁场刺激组的细胞增殖能力较对照组增强。结论 15Hz、0.1mT脉冲电磁场对体外培养的大鼠成骨细胞增殖具有促进作用,但强度超过0.5mT的脉冲电磁场对成骨细胞增殖无明显促进作用,如果强度≥1mT反而会导致成骨细胞的死亡。

Objective To observe the growth and proliferation of rat osteoblasts under the pulsed electromagnetic field by using the live cell imaging technology and to explore the influence on the growth and proliferation of rat osteoblasts under the different strength of pulsed electromagnetic fields. Methods At first, the survival and proliferation ability of osteoblasts was detected under the four different pulsed electromagnetic fields （15 Hz with the magnetic field strength of 0. 1 mT ,0.3 mT,0.5 mT,l. 0 roT）by the MTT assay. Then, the above results were compared with the control group in order to gain the best strength of pulsed electromagnetic field. Depending on the results above, 15 Hz,0. I mT was selected in the pulsed electromagnetic field stimulation group. Then the live cell imaging technology was used to record the process of osteoblasts＂ growth and proliferation iu the pulsed electromagnetic fields stimulation group and control group by the Time-Lapse control way and the rate of the adherence and cytodicresis was observed dynamically by the Multi-point parallel control way. Meanwhile, the proliferation of both two groups was also detected synchronously by the MTT assay. Results The primary osteoblasts with cultured for three days, were stimulated for another three days under the 15 Hz pulsed electromagnetic fields continuously. According to the results of the MTT assay, 1.0 mT group of cells almost all died, the cell proliferation of 0. 5 mT group and the control group was no significant difference, the cell proliferation of 0. 3 mT, 0. 1 mT group compared with the control group was increased. By the live cell imaging Time-Lapse parallel records, dynamic observation and analysis, rate of cell attached under 15 Hz, 0. 1 mT pulsed electromagnetic fields compared with the control group was no significant difference, but the rate of cytodicresis was fast （P 〈 0. 05 ）. Meanwhile, MTT synchronous detection method also proved the same result above. Conclusion The proliferation of rat osteoblasts which were under 15 Hz, 0.1 mT pulsed electromagnetic fields were promoted, but under more than 0.5 mT strength, the proliferation had no significant promotion, and if under more than 1 mT strength, osteoblasts will die.