Effect of ultraviolet irradiation on adhesion of cells and microorganisms on titania films

Titania (TiO 2 ) is a photocatalyst with ultraviolet (UV) responsiveness. When titania is irradiated with UV light, the hydrophilicity of its surface improves considerably, creating a superhydrophilic surface. Consequently, UV irradiation could be a useful method to control the adhesion of cells and microorganisms. In this study, titania films were prepared using a sol-gel method, and the adhesion of osteoblast-like cells and Escherichia coli with and without UV pre-irradiation was examined. In the cell-adhesion test, UV pre-irradiation did not notably affect the number of adhered cells, although superhydrophilicity was induced. In the E. coli adhesion test, the number of E. coli adhered to the substrates increased with UV pre-irradiation. Consequently, the potential to control the adhesion of microorganisms via UV pre-irradiation was demonstrated.