Abstract
Titanium dioxide (TiO_2) has been used in many industrial ways, such as in pigments, photo-catalysts and UV fillers. Recently, this material has attracted much interest in environmental or medical fields as an antibacterial or deodorization agent due to its photoreactivity. For example, Cai et al. reported that photoexited TiO_2 particles effectively induced cytotoxicity against HeLa cancer cells [1]. Morioka et al. also reported that TiO_2 particles showed an antibacterial effect against oral germ, cariogenic streptococcus mutans [2]. Nontoxicity to experimental animals is also one of its unique properties. TiO_2 is, therefore, very useful for medical fields.
NSTL