2005 Volume 68 Issue 2 Pages 213-219
We investigated the effect of photocatalytic reactions of titanium dioxide fine powder on rat tongue carcinoma cells induced by 4-nitroquinoline 1-oxide. Three types of titanium dioxide fine powder, anatase type ST-41, rutile type TP-3 and mixed type P-25, were added separately to culture fluid for 48 hours, followed by exposure to 254nm ultraviolet light. The cell survival rate was decreased in the cells cultured with any type of titanium dioxide fine powder, and the decrease was marked in the cells cultured with ST-41. Furthermore, the cell survival rate was decreased in correlation with irradiation time and concentration in the ST-41 group. We found an apoptotic ladder pattern which suggests that the apoptosis was associated with the mechanism of cultured cell kill. These findings indicate that the photocatalytic reactions of ST-41 titanium dioxide fine powder may provide a new modality of cancer treatment.
