Nanosurface modification of Ti64 implant by anodic fluorine-doped alumina/titania for orthopedic application

Abstract

Given that titanium (Ti)-based alloys have been paid more attention for various biomedical applications, the formation of the nanostructured coatings on Ti-based alloys may be a promising strategy for further preclinical developments. Therefore, the present study reports a new hybrid approach that integrates the engineering and scientific aspects into a single operational framework, in which a highly efficient fluorine-doped alumina/titania coating was developed on the Ti64 implant to improve its performance in long-term operation. Besides, due to the effect of surface tuning on the biomineralization of the system, the in-situ doping mechanism and its impacts on the in-vitro bioactivity of the implant were evaluated. From the microstructural observations, a homogeneous mixed oxide nanoporous structure with a pore size between 18 and 29 nm was developed following one-step mild anodization (2 h) of the magnetron sputtered aluminum (Al) thin film on Ti64 substrate in 0.5 wt% NH4F with 4 ml de-ionized water in ethylene glycol at 20 °C using the applied potential of 60 V. The Rietveld refinement technique not only confirmed the formation of these mixed oxide phases but also provided promising refined data on the structural properties of the samples. In addition, improvements in mechanical performance, wettability and in vitro bioactivity of the system were obtained by the proposed nanosurface modification.