Sol-gel synthesis, characterization and properties of TiO2 and Ag-TiO2 coatings on titanium substrate

- TiO2 and Ag-TiO2 coatings were prepared by sol-gel method on Ti at low temperature.
- The presence of Ag is identified by UV/Vis, XRD, EDS and electrochemical response.
- Adhesion of P. aeruginosa is reduced and bacteria shape is changed on coated Ti.
- The Ag-TiO2 coatings are not cytotoxic to osteoblastoma cells.

The aim of this study is the sol-gel synthesis of TiO2 and Ag-TiO2 coatings which would provide corrosion resistance and reduce bacterial adhesion when deposited on titanium substrate. The molar ratios of AgNO3:H2O2:TiO2 were 0.0037:2:1. The composition of the sols was checked using UV/Vis spectroscopy. The properties of the obtained coatings were investigated using X-ray diffraction, scanning electron microscopy with chemical analysis, and 3D profilometry. Electrochemical studies were performed in a simulated physiological solution and demonstrated good protection of the TiO2 and Ag-TiO2 coatings for the titanium substrate. Dissolution of silver from the coating was qualitatively followed by electrochemical impedance spectroscopy. The adhesion of Pseudomonas aeruginosa as a biofilm forming bacteria commonly found in orthopaedic applications was reduced in the presence of silver and the bacteria shape destroyed. No cytotoxicity of the coatings on human osteoblastoma cells was noticed. Our results suggest that TiO2 and Ag-TiO2 coatings obtained by a green synthesis sol-gel route at low temperature can be tailored to offer properties suitable for biomedical applications.

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