Corrosion resistance and biocompatibility of titanium surface coated with amorphous tantalum pentoxide

Tantalum pentoxide (Ta₂O₅) possesses good corrosion resistance and biocompatibility. This study aimed to improve the corrosion resistance and biocompatibility of titanium (Ti) by coating it with an amorphous Ta₂O₅ surface layer. An amorphous Ta₂O ₅ layer was prepared on the Ti surface using a simple hydrolysis-condensation process at room temperature. The surface characteristics of the test specimens were analyzed using X-ray photoelectron spectroscopy, glancing angle X-ray diffraction, field emission scanning electron microscopy, and contact angle measurements. The corrosion resistance of the test specimens was evaluated from the potentiodynamic polarization curves and ion release measurements in simulated blood plasma (SBP). The biocompatibility of the test specimens was evaluated in terms of the protein (albumin) adsorption, cell adhesion, and cell growth of human bone marrow mesenchymal stem cells (hBMSCs). The amorphous Ta₂O₅ layer with a porous micro-/nano-scale topography, which was deposited on the Ti surface using a simple hydrolysis-condensation process, increased the corrosion resistance (i.e., increased the corrosion potential and decreased the anodic current and ion release) of the Ti in the SBP and improved the surface wettability, albumin adsorption, and cell adhesion. We conclude that the presence of an amorphous Ta₂O₅ layer on the Ti surface increased the corrosion resistance and biocompatibility of Ti.