Effectiveness of physicochemical techniques on the activation of Ti6Al4V surface with improved biocompatibility and antibacterial properties

Today, Ti6Al4V alloy is the most used and manufactured metallic implantable biomaterial in biomedical industry. However, in recent years it has demonstrated that Ti6Al4V based biomaterials could induce harmful diseases to human health in long-term implantations. Thus, biomedical community makes great efforts in order to improve the biocompatibility of Ti6Al4V implants and to afford additional antibacterial properties. For this, one promising strategy is the activation of Ti6Al4V surface through simple and industrially scalable physicochemical techniques that involve the increase of the thickness of the surface oxidation (TiO2) and the creation of active hydroxyl groups (Ti-OH). In this work, Ti6Al4V biomaterials were activated with chemical wet (CWT), electrochemical (ET), and physical oxygen plasma (POPT) treatments. Their surface activation effectiveness was evaluated in terms of surface damage, changes in surface roughness, wettability, and oxidation and hydroxylation capability (Ti-OH/TiO2 ratio). So, results show that acidic HCl:H2O2 piranha CWT of Ti6Al4V surfaces is the most effective surface activation procedure with improved surface reactivity (highest Ti-OH/TiO2 ratio), cytocompatibility, cell proliferation, and hemocompatibility. Antibiofilm activity of pristine Ti6Al4V was also enhanced by acidic HCl:H2O2 piranha treatment, leading to a decrease in bacterial adhesion of 30 % against S. aureus and E. coli.