Evaluation of Synergistic Effect of TiO2 Nanoparticles and Gamma Rays on Human Breast Cancer Cell Line

Nowadays، cancer is the second cause of mortality in the world and among its variants; the most common cancer in women is the breast cancer. One of the methods for cancer treatment is radioth-erapy، in which to enhance the efficiency of radiation therapy some of radio sensitizer can be used for enhancing tumor cell radiosensitivity. Some nanopa-rticles can be considered as a sensitizer because they enhance the cytotoxicity due to oxidative stress and increase the free radicals، especially reactive oxygen species (ROS)، within cells resulting in cell death. In this study، elevated synergistic effect of TiO2 nanoparticles as radiosensitizer was evaluated in presence of cobalt-60 gamma rays on human breast cancer cell line. After cell culture، the human breast adenocarcinoma cell line (MCF-7 cells) was exposed to 2 Gy of radiation and 30 µg/ml concentration of the aforementioned nanoparticles. Viability was calculated using (3- [4، 5-dimethylthiazol-2-yl] -2،5 diphenyl tetrazolium bromide) MTT assay. Viability of cells in presence of gamma radiation and the nanoparticles، sig-nificantly reduced compared to the viability of cells exposed only to radiation or nano-particle، alone. The effect may dependent on nanoparticle crystals type and conce-ntration. Discussion & Nano-TiO2 inc-reased sensitivity of breast cancer cells to gamma radiation، due to an increase in ROS production and cytotoxicity. Anatase crystals have more severe effects than rutile crystal because of having a larger surface area and creation of more free radicals. Therefore، this nanoparticle has the potent-ial to be used as a radiosensitizer.