Evaluating Effects of Nitrogen-Doped-Titanium Dioxide in Photodynamic Therapy of Breast Cancer MCF-7 Cells

Titanium dioxide (TiO2) nanoparticles (NPs) activated by ultraviolent light (UV) have been recently proposed as a nano-photosensitizer (PS) for cancer therapy. However, because adverse effects of UV light, other dopped-TiO2 NPs with ability of activation by safe light sources, such as visible light, have been recommended for photodynamic therapy (PDT) purposes. The aim of this study is to evaluate effects of photodynamic N-TiO2 NPs in MCF-7 cell line as human epithelial breast cancer cell line.
MCF-7 cells were treated with different concentrations of N-TiO2 NPs and a visible light source was used for their photocatalytic activation. Trypan blue staining was performed to investigate the rate of cell viability and cell growth at 24h and 48h upon irradiation. Acridine Orange/Ethidium Bromide (AO/EtBr) staining and deoxyribonucleic acid (DNA)-laddering assay were used for detecting the mode of cell death.
Treatment of MCF-7 cells with N-TiO2 NPs, up to 100 µg/ml was inert and did not significantly affect growth and viability. However, with the increasing at concentrations of NP, the rate of cell death increased considerably upon visible-light irradiation. The AO/EtBr double staining and DNA-ladder assay showed that the mode of cell death induced by photodynamic N-TiO2 NPs is mostly through apoptosis.
N-TiO2 NPs in conjugation with visible-light may be proposed as a safe approach for PDT of breast cancer cells.