Enhanced biological responses of a hydroxyapatite/TiO2 hybrid structure when surface electric charge is controlled using radiofrequency sputtering

We investigated whether surface roughness and control of surface electric charge of a hydroxyapatite (HA)/titanium oxide (TiO2) hybrid coating could enhance biological responses associated with bone formation. After acid etching, a titanium surface was modified with HA and TiO2 by the dual sputtering deposition technique using radiofrequency sputtering. These surfaces were analyzed for surface roughness and surface electric charge intensity. Rat bone marrow-derived osteoblast-like cells were cultured on HA/TiO2 hybrid surfaces with different electric charges. The attachment and spreading behavior of these cells were significantly increased on the hybrid surface (p