Static Magnetic Fields Up-regulate Osteoblast Maturity by Affecting Local Differentiation Factors

Abstract

Cell culture studies have shown that static magnetic fields induce osteoblastic differentiation at an early stage. However, the mechanisms of differentiated effects have not been well described. We postulated that static magnetic fields stimulate osteoblastic differentiation by regulating early local factors released by the cells. To examine our hypothesis, MG63 osteoblast-like cells were exposed continuously to 0.4-T static magnetic fields for 12, 24, 48, and 72 hours. The morphologic changes and matrix vesicles release were observed by scanning and transmission electron microscopy. The effects of static magnetic fields on levels of transforming growth factor-beta1, Type I collagen, osteopontin, and alkaline phosphatase were compared between the exposed and unexposed cells. The data suggest MG63 cells treated with static magnetic fields have more differentiated morphologic features. The local regulatory factors produced by static magnetic field-treated cells were greater than those of the control cultures. These findings provide evidence that static magnetic fields affect osteoblastic maturation by up-regulating early local factors.

Pulsed electromagnetic fields enhance BMP‐2 dependent osteoblastic differentiation of human mesenchymal stem cells

“…However, because coils were active in only one incubator, any resulting vibrations might not have been equivalent in the control and experimental cultures. At harvest [days 0 (confluence), 6,12,16,20,24], cultures were examined for expression of an osteoblastic phenotype based on ALP specific activity of cell layer lysates and osteocalcin levels in the conditioned media.…”

“…19 Static magnetic fields may act on osteoblast differentiation via similar signaling pathways. 20,21 While biophysical forces appear to regulate osteoblasts via mechanisms involving growth factors and cytokine release, differences in cell response are signal specific. However, it has been difficult to determine if differences in responses to biophysical factors are due to: the type of signal (PEMF, static magnetic fields, capacitively coupled electric fields, combined magnetic fields, or direct current) 22,23 ; the form or duration of a specific signal 24 ; or to differences in the cell culture model used.…”

The effect of an intramedullary implant with a static magnetic field on the healing of the osteotomised rabbit femur

“…Animal experiments have shown that long-term local SMF stimulation by permanent magnets can increase bone strength [6]. There is evidence that SMF affect osteoblastic maturation by up-regulating local factors [14]. There are some potential advantages for SMF.…”

“…The use of specific electromagnetic fields for the treatment of nonunions is well known [2,14,20]. The union rates of ununited fractures treated with pulsed electromagnetic fields (PEMF) are greater than 80% [1,11,20].…”

Static Magnetic Field on the Effects of Oral Hard and Soft Tissue: Review

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