Effect of periodic nanostructures produced with femtosecond laser for wavelength of 388 and 775 nm on cell spreading

Titanium (Ti) is one of the most used biomaterials. However, it has problem for biocompatibility. Adding new function to Ti surface is necessary. Coating of titanium dioxide (TiO₂) film on Ti surface is a useful method for improving the biocompatibility of Ti. We have a film coating method with an aerosol beam. Control of cell spreading by periodic nanostructures formation with femtosecond laser is also useful method for adding new function to TiO₂ film. The control of cell spreading is important for the development of advanced biomaterials. In this study, the periodic nanostructures with periods of 130 and 230 nm were formed on a film using a femtosecond laser with wavelengths of 388 and 775 nm, respectively. Effect of periods on cell spreading was investigated. Cell tests showed that cells spread along the grooves of the periodic nanostructures with periods of 130 and 230 nm, whereas cell spreading did not have a definite direction on a film without periodic nanostructures. Distribution of angle of cell spreading on laser irradiated area was examined. These results suggested that controlling the cell spreading on periodic nanostructures with period of 230 nm was better than that of 130 nm.