Magnetic orientation of collagen and bone mixture

There are no reported studies on the effects of magnetic fields on osteoblast collagen secretory processes during osteoblast differentiation. It is important to understand the effect of magnetic-field exposure on osteoblast collagen secretory processes since bone is remodeled continuously by bone-forming osteoblasts and bone-resorbing osteoclasts. We hypothesized that a mixture of collagen and osteoblasts, an adherent cell, would orient perpendicular to a magnetic field since collagen fibers are known to orient perpendicular to magnetic fields. As the osteoblasts proliferate along the collagen fibers, the magnetic orientation of the osteoblasts will change to a perpendicular direction as well. We tested this hypothesis by comparing the magnetic orientation of osteoblasts and the magnetic orientation of an osteoblast and collagen mixture after exposure to 8 T magnetic fields, which were produced by a superconducting magnet, or without exposure to magnetic fields (control). We succeeded in producing the magnetic orientation of osteoblasts without collagen after long-term exposure to magnetic fields. We observed that osteoblasts oriented parallel to the magnetic fields, but a mixture of osteoblasts and collagen oriented perpendicular to the magnetic fields. The magnetic control of osteoblast orientation will help to clarify the underlying mechanisms of osteoblast differentiation, which is important for the development of potential medical and engineering applications such as tissue repair, artificial bone development, etc. (C) 2000 American Institute of Physics. [S0021-8979(00)47908-9].