Incorporating TiO2 nanoparticles to enhance corrosion resistance, cytocompatibility, and antibacterial properties of PEO ceramic coatings on titanium

This study aimed to investigate the influence of incorporating different concentrations (1, 3, and 5 g/l) of anatase-TiO 2 nanoparticles (NPs) on morphology, roughness, wettability, corrosion resistance, cytocompatibility, and antibacterial activity of porous coatings produced by plasma electrolytic oxidation (PEO) process on pure titanium. Microstructural studies evidenced the successful incorporation of TiO 2 NPs in the coatings. Increasing the concentration of TiO 2 NPs from 1 to 5 g/l led to reduced porosity and increased wettability, with no significant change in the surface roughness. The results of the electrochemical tests after 7 days of exposure to simulated body fluid (SBF) indicated that the highest corrosion resistance (2.292 MΩ cm 2 ) was obtained by the addition of 3 g/l TiO 2 NPs. The cytocompatibility test after 3 days of cell culture showed that lower concentrations of TiO 2 NPs, i.e., 1 and 3 g/l, provided the optimum conditions for adhering and flattening of MG63 cell on coatings surface. The antibacterial tests revealed that the more the TiO 2 NPs concentration was, the less bacterial adhesion and therefore, the better the antibacterial properties against Staphylococcus aureus (S. aureus ) bacteria were achieved. The addition of 5 g/l TiO 2 NPs into the electrolyte provided the antibacterial rate of 94.47% for the coating. The incorporation of TiO 2 NPs positively affects physico-chemical properties, cytocompatibility, and antibacterial behavior of pure titanium coated by PEO method.