Effect of low-frequency pulsed electromagnetic field on the mice MC3T3-E1 cells proliferation, differentiation and mineralization

Objective To investigate the impacts of low-frequency pulsed electromagnetic fields (LFPEMFs) on proliferation, differentiation and mineralization of mouse osteoblastic cell line MC3T3-E1. Method MC3T3-E1 osteoblast-like cells were divided into 4 groups: control group, 1.10mT field group, 3.10mT field group and 4.10mT field group. The experimental materials were collected at two time points: 14 and 21 days after magnetic field irradiation. The cells were stimulated by a pulsed magnetic field with a certain frequency (0.15 Hz) and different intensities (1.10 mT, 3.10 mT, 4.10 mT) under normal culture conditions. Cell counting kit (CCK8) was used to perform 24 hours after the cells were treated. 14 days after cell treatment, alkaline phosphatase (ALP) staining, Osteocalcin (OCN) enzyme-linked immunosorbent assay (ELISA) and Western Blotting (WB) of runt-related transcription factor 2 (RUNX 2) were performed. Alizarin red staining, OCN ELISA and Collagen I (Cola I) WB were performed on all 4 groups of cells after 21 days of treatment. Results No toxic response was observed in MC3T3-E1 osteoblast cells exposed to different intensity of LFPEMFs for 24 hours. Compared with the control group, the expression of ALP, OCN and RUNX 2 in MC3T3-E1cells treated with different intensity of LFPEMFs for 14d were significantly increased. Protein expression also increased with the increase of intensity. Conclusion Fixed-frequency pulsed electromagnetic fields can promote the osteogenic differentiation and mineralization, which are also magnetic field intensity dependent. The results provide evidences for intervention of fracture healing and anti-osteoporosis treatment.