The influence of titania-zirconia-zirconium titanate nanotube characteristics on osteoblast cell adhesion

Studies of biomaterial surfaces and their influence on cell behavior provide insights concerning the design of surface physicochemical and topography properties of implant materials. Fabrication of biocompatible metal oxide nanotubes on metallic biomaterials, especially titanium alloys such as Ti50Zr via anodization, alters the surface chemistry as well as surface topography of the alloy. In this study, four groups of TiO2-ZrO2-ZrTiO4 nanotubes that exhibit diverse nanoscale dimensional characteristics (i.e. inner diameter D-i, outer diameter Do and wall thicknesses W-t) were fabricated via anodization. The nanotubes were annealed and characterized using scanning electron microscopy and 3-D profilometry. The potential applied during anodization influenced the oxidation rate of titanium and zirconium, thereby resulting in different nanoscale characteristics for the nanotubes. The different oxidation and dissolution rates both led to changes in the surface roughness parameters. The in vitro cell response to the nanotubes with different nanoscale dimensional characteristics was assessed using osteoblast cells (SaOS2). The results of the MTS assay indicated that the nanotubes with inner diameter (D-i) approximate to 40 nm exhibited the highest percentage of cell adhesion of 41.0%. This result can be compared to (i) 25.9% cell adhesion at D-i approximate to 59 nm, (ii) 33.1% at D-i approximate to 64 nm, and (iii) 33.5% at D-i approximate to 82 nm. The nanotubes with D-i approximate to 59 nm exhibited the greatest roughness parameter of Sa (mean roughness), leading to the lowest ability to interlock with SaOS2 cells. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.