TiO2 nanostructures: voltage influence in corrosion resistance and human osteosarcoma HOS cell responses

Abstract

Objectives: To develop TiO2 nanostructures using an electrochemical process and evaluate the influence of voltage in the generation of nanotubes and the adhesion of human osteosarcoma cells on anodizing Ti6Al4V surfaces. Methods/ Statistical Analysis: TiO2 nanostructures on Ti6Al4V in a solution of 1M H3PO4 + 0.2% wt HF for 1 hour at 14 V, 20 V and 25 V were obtained. Surface morphology was evaluated by using scanning electron microscopy and the corrosion behavior of the anodized surfaces was studied using potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS). Cell toxicity was evaluated using a colorimetric MTT assay and the cell morphology was reviewed using a fluorescence microscope. Findings: TiO2 nanotubes with diameters of 54.35 nm, 90.84 nm and 85.02 nm were obtained by anodizing at 14 V, 20 V and 25 V respectively. Using an anodizing process an organized and uniform structure was obtained with a density of 130/μm2, 60/μm2 and 6/μm2, for the samples anodized at 14 V, 20 V and 25 V respectively. The anodized samples presented nanotubes with intertubular spaces between 10 and 14 nm. The results showed a lower corrosion rate of the anodized surfaces compared to the base material (UT-Ti64), in addition, it was observed that the samples with higher cell count adhered to its surface have higher cell viability percentages, 80% for the samples anodized at 20 V and 25 V. Application/Improvements: The results show that nanostructures could be customized depending on the applications such as higher corrosion resistance and better transport of nutrients favoring the cell metabolism.