Cytocompatibility and antibacterial activity of nanostructured H(2)Ti(5)O(11)·H(2)O outlayered Zn-doped TiO(2) coatings on Ti for percutaneous implants

To improve skin-integration and antibacterial activity of percutaneous implants, the coatings comprising an outer layer of H(2)Ti(5)O(11)·H(2)O (HTO) nanoarrays and an inner layer of microporous Zn-doped TiO(2) were fabricated on Ti by micro-arc oxidation (MAO) followed with hydrothermal treatment (HT). During HT process, a large proportion of Zn(2+) migrated out from TiO(2) layer. TiO(2) reacted with OH(−) and H(2)O, resulting in the nucleation of HTO. The nuclei grew to nanoplates, nanorods and nanofibres with HT process prolonged. Simultaneously, the orientation of nanoarrays changed from quasi-vertical to parallel to substrate. Compared to Ti, adhesion and proliferation of fibroblasts were enhanced on as-MAOed TiO(2) and HTed coatings. The phenotype, differentiation and extracellular collagen secretion were obviously accelerated on vertical nanorods with proper interspace (e.g. 63 nm). HTed coatings showed enhanced antibacterial activity, which should be ascribed to the nano-topography of HTO.