Synthesis of bioactive TiO2 nanotubular thin films: Exploring biocompatibility and biocorrosion behavior in simulated body environments

Abstract

Nanotexturization of the surface of metallic implants has been a promising strategy for enhancing their performance but is obtained in relatively long anodization periods (>1 h). This study aimed to investigate the formation of bioactive TiO2 NTs films and evaluate their biocorrosion resistance. TiO2 NTs were grown from commercially pure titanium (CPTi) and Ti6Al4V by potentiostatic anodization varying time (10, 30, 60, and 120-min) in ethylene glycol, NH4F, and 0.5 % simulated body fluid electrolyte. Morphology, microstructure, wettability, and electrochemical behavior (in buffered solution and bacteria inoculum) were investigated. Results show that anodic CPTi-based samples presented optimized wettability, hydroxyapatite deposition, and corrosion resistance in a buffered solution. Anodization time tailors pore diameter and hydroxyapatite deposition of samples from both substrates, beyond a threshold of 30–60 min. Rapid anodized samples (10 min) presented the lower corrosion rates from all investigated samples. Annealing treatment improved the wettability and hydroxyapatite deposition due to anatase stabilization but induced lower corrosion resistance. Upon exposure to bacterial medium, both anodic 10-min (CPTi) and annealed (CPTi and Ti6Al4V) based-samples displayed biocorrosion resistance, except for TiCP-based samples with S. aureus. Thus, chosen surface treatments can enhance some implants' desirable characteristics.