The biocompatibility and durability of titanium alloys, such as Ti-6Al-4V, are critical for their performance in biomedical applications. However, their susceptibility to corrosion in physiological environments remains a challenge. This study explores the synthesis and application of alginate-based hydrogels loaded with copper oxide nanoparticles (CuO NPs) as a protective coating on untreated and SLA-treated Ti-6Al-4V substrates. Alginate, a biopolymer with high hydrophilicity and biocompatibility, was selected for its potential to create a uniform hydrogel layer, while CuO NPs were incorporated for their known antimicrobial and corrosion-inhibitory properties. SLA treatment was employed to enhance surface roughness, promoting hydrogel adhesion.

The synthesized hydrogels were characterized using FTIR, confirming the successful incorporation of CuO NPs. Adhesion testing demonstrated superior hydrogel attachment to SLA-treated titanium surfaces due to increased surface roughness and energy. Corrosion resistance was evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in a simulated body fluid. The results revealed significant improvement in corrosion resistance for the hydrogel-coated samples compared to bare titanium, with the CuO NP-loaded hydrogels exhibiting the highest protection. This enhancement is attributed to the hydrogel's barrier properties, which limit ion diffusion and reduce electrolyte access to the metal surface, counteracting the expected corrosion-promoting effect of a wet environment.

This research highlights the potential of SLA-treated, CuO NP-enriched alginate hydrogels to improve the longevity and performance of titanium implants by addressing both biocompatibility and corrosion resistance challenges.