Ultrathin\nALD Coatings of Zr and V Oxides on Anodic\nTiO<sub>2</sub> Nanotube Layers: Comparison of the Osteoblast Cell\nGrowth

The current study\ninvestigates and compares the biological effects\nof ultrathin conformal coatings of zirconium dioxide (ZrO<sub>2</sub>) and vanadium pentoxide (V<sub>2</sub>O<sub>5</sub>) on osteoblastic\nMG-63 cells grown on TiO<sub>2</sub> nanotube layers (TNTs). Coatings\nwere achieved by the atomic layer deposition (ALD) technique. TNTs\nwith average tube diameters of 15, 30, and 100 nm were fabricated\non Ti substrates (via electrochemical anodization) and were used as\nprimary substrates for the study. The MG-63 cell growth and proliferation\nafter 48 h of incubation on hybrid TNTs/ZrO<sub>2</sub> and TNTs/V<sub>2</sub>O<sub>5</sub> surfaces was evaluated in comparison to the\nuncoated TNTs of each diameter. The density of viable MG-63 cells\nwas assessed for all the TNT surfaces, along with the cell morphology\nand the spreading behavior (i.e., the cell length). The ultrathin\ncoatings retained the original morphology of the TNTs but changed\nthe surface chemical composition, wettability, and cell behavior,\nwhose interplay is the subject of the present investigation. These\nfindings offer interesting views on the influence of the composition\nof biomedical implant surfaces, triggered by ALD ultrathin coatings\non them. The outcomes of this work shed light on the assessment of\nthe biocompatibility of the two different ALD coatings.