Effects of different durations of 50 Hz 3.6 mT sinusoidal electromagnetic field on proliferation and differentiation of human umbilical cord stem cells in vitro
Objective:To investigate the effects of different durations of 50 Hz 3.6 mT sinusoidal electromagnetic fields (SEMFs) on the proliferation and differentiation of human umbilical cord stem cells (HUCSCs) in vitro. Methods:The HUCSCs were isolated from the neonate umbilical cord and randomly divided into 6 groups after one passage. The treatment groups were under 50 Hz 3.6 mT SEMFs respectively for 0.5,1.0,1.5,2.0 h,and 2.5 h each day,while the control group underwent no SEMFs treatment. All groups were observed under the contrast phase microscope each day. The proliferation was tested by MTT. At 15 d and 17 d after the SEMFs treatment the calcified nodules were stained by alizarin red and vonkossa respectively. At 4 d and 6 d after the SEMFs treatment the Collagen-Ⅰand BMP-2 mRNA were tested by real time PCR. At 10,12,14 d,and 16 d after the SEMFs treatment the ALP activity was tested. Results:the SEMFs were arranged in spiral appearance 7~9 d after the treatment.The SEMFs promoted the proliferation of HUCSCs,except in 0.5 h group. The ALP activity in 0.5 h and 1.0 h groups significantly increased at 14 d and 16 d after the SEMFs treatment. The calcified nodules number in 0.5 h and 1.0 h groups significantly increased after the SEMFs treatment. The Collagen-Ⅰand BMP-2 mRNA expression in 0.5 h and 1.0 h groups significantly increased after the SEMFs treatment. Conclusion:1.0,1.5,2.0 h,and 2.5 h treatment of 50 Hz 3.6 mT SEMFs promoted the proliferation of HUCSC,0.5 h and 1.0 h treatment of 50 Hz 3.6 mT SEMFs significantly enhanced the osteogenesis differentiation of human umbilical cord.