Strong Static Magnetic Field Stimulates Bone Formation to a Definite Orientation In Vitro and In Vivo

Abstract

The induction of bone formation to an intentional orientation is a potentially viable clinical treatment for bone disorders. Among the many chemical and physical factors, a static magnetic field (SMF) of tesla order can regulate the shapes of blood cells and matrix fibers. This study investigated the effects of a strong SMF (8 T) on bone formation in both in vivo and in vitro systems. After 60 h of exposure to the SMF, cultured mouse osteoblastic MC3T3-E1 cells were transformed to rodlike shapes and were orientated in the direction parallel to the magnetic field. Although this strong SMF exposure did not affect cell proliferation, it up-regulated cell differentiation and matrix synthesis as determined by ALP and alizarin red stainings, respectively. The SMF also stimulated ectopic bone formation in and around subcutaneously implanted bone morphogenetic protein (BMP) 2-containing pellets in mice, in which the orientation of bone formation was parallel to the magnetic field. It is concluded that a strong SMF has the potency not only to stimulate bone formation, but also to regulate its orientation in both in vitro and in vivo models. This is the first study to show the regulation of the orientation of adherent cells by a magnetic field. We propose that the combination of a strong SMF and a potent osteogenic agent such as BMP possibly may lead to an effective treatment of bone fractures and defects.

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

“…The role of electromagnetic stimulation on delayed and nonunions of fractures is suggested by a large number of preclinical in vitro and in vivo studies which, collectively, show that exposure to electromagnetic energy stimulates the synthesis of extracellular matrix molecules [15,18]. Magnetic field treatment is a therapeutic modality that has shown promise as a nonsurgical treatment for nonunions of long bones.…”

The static magnetic field accelerates the osteogenic differentiation and mineralization of dental pulp cells

“…Static magnetic field (SMF) has been used advantageously in various orthodontic treatments (Noar and Evans 1999). Studies have demonstrated that SMF increased bone repair (Darendeliler et al 1997), bone deposition (Darendeliler et al 1995) and bone formation in vitro and in vivo (Kotani et al 2002). SMF was also used to prevent the decrease in bone density caused by surgery or implantation (Yan et al 1998).…”

Biological Effects of Electromagnetic Fields and Recently Updated Safety Guidelines for Strong Static Magnetic Fields

“…The torque orients certain diamagnetic materials, such asˆbrin and collagen, and some cells, such as osteoblasts and Schwann cells. 15,16 Radical pair eŠect…”