Enhanced Biocompatibility in Anodic TaOx Nanotube Arrays

Abstract

This study first investigates the biocompatibility of self-organized TaOx nanotube arrays with different nanotube diameters fabricated by electrochemical anodization. All as-anodized TaOx nanotubes were identified to be an amorphous phase. The transition in surface wettability with TaOx nanotube diameters can be explained based on Wenzel’s model in terms of geometric roughness. In vitro biocompatibility evaluation further indicates that fibroblast cells exhibit an obvious wettability-dependent behavior on the TaOx nanotubes. The 35-nm-diameter TaOx nanotube arrays reveal the highest biocompatibility among all samples. This enhancement could be attributed to highly dense focal points provided by TaOx nanotubes due to higher surface hydrophilicity. This work demonstrates that the biocompatibility in Ta can be improved by forming TaOx nanotube arrays on the surface with appropriate nanotube diameter and geometric roughness.