The Effect of Pulsed Electromagnetic Field in Human Intervertebral Disc Cell / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: An in vitro experiment. OBJECTIVES: To assess the effect of pulsed sinusoidal EMF on human intervertebral disc (IVD) cells. LITERATURE REVIEW SUMMARY: Electromagnetic field (EMF) is known to modify some relevant physiological parameters of cells cultured in vitro, such as proliferation, synthesis, secretion of growth factors and transcription. EMF induces bone formation in delayed, non union and spinal fusion models. Also, the exposure of EMF has been shown to protect against the hazardous effect of smoking in the rabbit IVD. MATERIALS AND METHODS: Human IVD cells were three-dimensionally cultured in alginate beads and exposed to a 650 omega, 1.8millitesla magnetic flux density, 60Hz sinusoidal wave of EMF. The cultures were divided into the control and EMF groups, with various exposure times. The cytotoxicity, and DNA and proteoglycan syntheses were measured by the MTT assay, and [3H]-thymidine and [35S]-sulfate incorporation, respectively. RT-PCRs were performed for aggrecan, and collagen types I and II mRNA expressions. RESULTS: There was no recognizable cytotoxicity in the EMF group, but cellular proliferation was stimulated (p<0.05). Newly synthesized proteoglycan, normalized by DNA synthesis, was decreased in the EMF group (p<0.05) as were the expressions of aggrecan (48hour exposure) and type II collagen (72 hours exposure) mRNA compared to the control group. CONCLUSIONS: EMF seems to be hazardous in the synthesis of the chondrogenic matrix, while marginally beneficial in the cellular proliferation of human IVD cells.