Static magnetic field exposure promotes differentiation of osteoblastic cells grown on the surface of a poly-L-lactide substrate.

This study investigated the effects of static magnetic fields on the differentiation of MG63 cells cultured on the surface of poly-L-lactide (PLLA) substrates. The cells were continuously exposed to a 4,000 Gauss-static magnetic field (SMF) for 5 days. The proliferation effects of the SMF were measured by MTT assay. Morphologic changes and extracellular matrix release were observed by scanning electron microscopy. The effects of the SMF on alkaline phosphatase activity levels were compared between exposed and unexposed cells. The SMF-exposed cells exhibited decreased MTT values after 1 and 3 days of culture. In addition, SMF exposure promoted the expression of extracellular matrix in MG63 cells on the PLLA substrate. After 1 day, the alkaline phosphatase-specific activity of SMF-exposed MG63 cells was significantly increased (P < 0.05) with a ratio of 1.5-fold. These results show that MG63 cells, seeded on a PLLA disc and treated with SMF, had a more differentiated phenotype.