Tailored Surface Modification of Titanium Alloys for Controlled Drug Release

This master's thesis focuses on the electrochemical anodization of titanium and Ti6Al4V alloy to create titania nanotubes (TNTs) for biomedical applications, aiming to enhance biocompatibility, osseointegration, and crucially, achieve controlled drug release. The study thoroughly investigated the optimization of anodization parameters, including acid pre-treatment and two-step anodization, to produce highly uniform and well-ordered TNTs on pure titanium substrates, demonstrating precise control over nanotube dimensions. The research also extended to additively manufactured Ti6Al4V alloy samples, revealing that the essential microstructure of "as-built" and "bulk" sections influences nanotube formation. A key innovative aspect was the exploration of current-controlled anodization to engineer specific internal TNT geometries, hypothesized to prolong drug release. However, contrary to expectations, experimental results consistently showed a faster drug release rate from samples produced via constant current anodization compared to constant voltage samples. This finding suggests that, under the explored parameters, this method is not conducive to sustained drug release. The study acknowledges the significant challenges posed by the nanoscale environment, the precision required for analytical techniques, and the minute drug quantities, which contribute to observed variability and difficulties in simple drug loading methods. In conclusion, while the work successfully established methods for precise TNT fabrication on both pure titanium and additive manufactured alloys, the attempt to leverage current-controlled anodization for prolonged drug release yielded unexpected results, highlighting complexities in tailoring nanoscale drug delivery. Future work is imperative to refine current-controlled anodization strategies, explore advanced drug loading techniques, optimize microchannel design, conduct deeper microstructural analysis of additive manufactured samples, and undertake rigorous in vitro and in vivo validations to advance the field of functionalized titanium implants.