Novel Photodynamic Therapy Using Water-dispersed TiO2-Polyethylene Glycol Compound: Evaluation of Antitumor Effect on Glioma Cells and Spheroids In Vitro

作者：Yamaguchi Shigeru; Kobayashi Hiroyuki; Narita Takuhito; Kanehira Koki; Sonezaki Shuji; Kubota Yoshinobu; Terasaka Shunsuke^*; Iwasaki Yoshinobu

来源：Photochemistry and Photobiology, 2010, 86(4): 964-971.

DOI：10.1111/j.1751-1097.2010.00742.x

Titanium dioxide (TiO2) is thought to be a photocatalytic agent excited by UV light. Our aim was to investigate the photocatalytic antitumor effect of water-dispersed TiO2 nanoparticles on C6 rat glioma cells and to evaluate the treatment responses by the spheroid models. Water-dispersed TiO2 nanoparticles were constructed by the adsorption of chemical modified polyethylene glycol (PEG) on the TiO2 surface (TiO2/PEG). Each monolayer and spheroid of C6 cells was coincubated with various concentrations of TiO2/PEG and subsequently irradiated with UV light. Damage of the cells and spheroids was evaluated sequentially by staining with the fluorescent dyes. The cytotoxic effect was correlated with the concentration of TiO2/PEG and the energy dose of UV irradiation. More than 90% of cells were killed after 13.5 J cm-2 of UV irradiation in the presence of 500 mu g mL-1 TiO2/PEG. The irradiated spheroids in the presence of TiO2/PEG showed growth suppression compared with control groups. In TiO2/PEG-treated spheroids, the number of Annexin V-FITC-stained cells gradually increased during the first 6 h, and subsequently propidium iodide-stained cells appeared. The results of this study suggest that newly developed photoexcited TiO2/PEG have antitumoral activity. Photodynamic therapy utilizing this material can be a clue to a novel therapeutic strategy for glioma.

• 出版日期2010-8