Preliminary analysis of magnetic particle techniques for activating mechanotransduction in bone cells

Magnetic beads were coated with RGD and adhered to primary human osteoblasts. During a 21-day culture, the osteoblasts plus adhered magnetic beads underwent a daily exposure to a cylical magnetic field via a permanent magnet thus applying a direct mechanical strain to the cells. After 21 days, preliminary results show that the cells plus magnetic beads were viable and had proliferated. A von-kossa stain showed a small amount of mineralized bone matrix produced at 21 days whereas the control groups showed no mineralized matrix production. RT-PCR at 21 days showed production of collagen 1 and GAPDH from each of the cell samples analysed. These preliminary results indicate that adherence of RGD-coated 4.5 micron ferromagnetic beads to primary human osteoblasts does not initiate cell necrosis up to 21 days in vitro. Also, mechanical stimulation of human osteoblasts by magnetic bead technology appears to have an influence on osteoblastic activity.