Bioactivity of micropatterned TiO2 nanotubes fabricated by micro-milling and anodic oxidation.

Although many methods have been proposed to fabricate a micro/nanostructure on titanium surface for enhanced cellular responses to implants, it has been challenging to construct an orderly micro/nanostructure. In this study, an ordered structure of micropatterned TiO2 nanotubes was produced on titanium surface by the combined use of micro-milling and anodic oxidation. The surface properties of different modified titanium samples were investigated by field emission scanning electron microscopy, laser scanning microscope, X-ray diffraction, and contact angle goniometer. The corrosion resistance of different samples was evaluated by an electrochemical workstation. A series of cell experiments were performed to evaluate the responses of osteoblasts to the modified titanium substrates. The results indicated that the surface roughness and hydrophilicity of micro/nanostructured titanium remarkably increased compared to the polished titanium. In addition, the corrosion resistance of micro/nanostructured titanium samples was also improved in comparison to the polished titanium samples. More importantly, the proliferation and differentiation of cells were significantly promoted on micro/nanostructure titanium substrates. This study provides a promising method to construct a regular micro- and nano-structure on titanium surface for cytocompatibility improvement.