Ultrathin TiO₂ Coatings via Atomic Layer Deposition Strongly Improve Cellular Interactions on Planar and Nanotubular...

This work aims to investigate the chemical and/or structural modification of Ti and Ti-6Al-4V (TiAlV) alloy surfaces to possess even more favorable properties toward cell growth. These modifications were achieved by (i) growing TiO₂ nanotube layers on these substrates by anodization, (ii) surface coating by ultrathin TiO₂ atomic layer deposition (ALD), or (iii) by the combination of both. In particular, an ultrathin TiO₂ coating, achieved by 1 cycle of TiO₂ ALD, was intended to shade the impurities of F- and V-based species in tested materials while preserving the original structure and morphology. The cell growth on TiO₂-coated and uncoated TiO₂ nanotube layers, Ti foils, and TiAlV alloy foils were compared after incubation for up to 72 h. For evaluation of the biocompatibility of tested materials, cell lines of different tissue origin, including predominantly MG-63 osteoblastic cells, were used. For all tested nanomaterials, adding an ultrathin TiO₂ coating improved the growth of MG-63 cells and other cell lines compared with the non-TiO₂-coated counterparts. Here, the presented approach of ultrathin TiO₂ coating could be used potentially for improving implants, especially in terms of shading problematic F- and V-based species in TiO₂ nanotube layers.