Abstract
Cytotoxicity of titanium dioxide (TiO&sub2;) thin films on Chinese hamster ovary (CHO-K1) cells was evaluated after 24, 48 and 72 h of culture. The TiO&sub2; thin films were deposited using direct current magnetron sputtering. These films were post-deposition annealed at different temperatures (300, 500 and 800 °C) toward the anatase to rutile phase transformation. The root-mean-square (RMS) surface roughness of TiO&sub2; films went from 2.8 to 8.08 nm when the annealing temperature was increased from 300 to 800 °C. Field emission scanning electron microscopy (FESEM) results showed that the TiO&sub2; films' thickness values fell within the nanometer range (290-310 nm). Based on the results of the tetrazolium dye and trypan blue assays, we found that TiO&sub2; thin films showed no cytotoxicity after the aforementioned culture times at which cell viability was greater than 98%. Independently of the annealing temperature of the TiO&sub2; thin films, the number of CHO-K1 cells on the control substrate and on all TiO&sub2; thin films was greater after 48 or 72 h than it was after 24 h; the highest cell survival rate was observed in TiO&sub2; films annealed at 800 °C. These results indicate that TiO&sub2; thin films do not affect mitochondrial function and proliferation of CHO-K1 cells, and back up the use of TiO&sub2; thin films in biomedical science.