Micropatterned TiO₂ nanotubes: fabrication, characterization and in vitro protein/cell responses

Effective bone repair and reconstruction after the implantation of Ti-based materials requires the provision of topological cues on the material's surface to promote specific biological responses from the surrounding environment. This is often realized by surface modification. In this paper, micropatterned TiO₂ nanotubes are fabricated on a Ti surface via a combination of photolithography and electrochemical anodization, by which micro- and nano-scale geometry can be controlled. The preparation conditions are optimized and the interaction between the micropatterning (via photolithography) and nanopatterning (via electrochemical anodization) processes is investigated in detail. The resulting materials are then used for protein adsorption and a cell adhesion test. It is found that protein adsorption and cell adhesion can "trace" the topological cues by presenting high selectivity between the micropatterned TiO₂ nanotubes and the Ti surface. We hope our study can benefit the research of Ti-based repairing materials, especially for those which need to manipulate protein adsorption and cell adhesion behavior.