Effect of TiO2 Nanotubes on Biological Activity of Osteoblasts and Focal Adhesion Kinase/Osteopontin Level

Osteoblasts are important cells for bone formation and play a major part in bone diseases and bone defects. Clinically, we usually adopt bone implants for related diseases. Also, nanotechnology is important in bones and joints. This study assessed the effects of TiO2 nanotubes of different diameters on osteoblast activity, FAK and OPN levels, aiming to provide an experimental foundation for selection of clinical bone implant materials. The morphology of MG-63 human osteosarcoma cells changed with expansion of TiO2 nanotubes’ diameter. From the biological activity, the cell proliferation and adhesion were enhanced as the diameter of the TiO2 nanotube was increased and its proliferation and adhesion were highest in the 100 nm TiO2 nanotube, which is related to increased ALP activity, FAK and OPN protein and mRNA expression. ELISA detected ALP activity and found that MG-63 cells cultured with 70 nm nanotube had strongest activity. Immune blotting and PCR results showed that, FAK and OPN activities were highest in 70 nm TiO2 nanotube cells. In summary, TiO2 nanotubes increased cell proliferation and adhesion by up-regulating the activities of FAK and OPN in a concentration-dependent relationship.