Abstract: In order to explore the mechanisms of killing cancer cells via nano-TiO2 photocatalytic oxidization, gastric cancer cell line BGC-823 was cultured as research object in this study. The morphologic changes were observed by inverted phase-contrast microscope, the apoptotic rates and cell cycle of BGC-823 cells were examined by flow cytometer. The results showed that nano-TiO2 photocatalytic oxidation caused the necrosis or secondary necrosis of BGC-823 cells, and inhibited the synthesis of DNA and their proliferation process, through arresting the G2/M phase and inducing apoptosis of BGC-823 cells. Significant arrest was observed and the apoptotic rates of BGC-823 cells reached 24.34% when the coated amount of TiO2 was 9.8×10-7 g/cm2 and the irradiation time was 40 min.

Key words: photocatalytic oxidization, nano-TiO2, gastric cancer cell line BGC-823, cell cycle, apoptosis