Singlet oxygen generation by sonication using a water-soluble fullerene (C60) complex: a potential application for sonodynamic therapy

Abstract

The generation of singlet oxygen (1O2) by sonicating a water-soluble complex of fullerene/poly(2-methacryloyloxyethyl phosphorylcholine) (C60/PMPC) was investigated for sonodynamic therapy (SDT). The effect of sonication time and the solubilized concentration of water-soluble fullerene C60 on the amount of generated 1O2 was studied. Singlet oxygen sensor green was used to confirm the generation of 1O2. 1O2 was generated from C60/PMPC under ultrasonic irradiation, and the amount of 1O2 increased with increasing solubilized C60 concentration and irradiation time. In cell viability tests, after 3 h of incubation, the cell viabilities were 10 and 84% in the presence of C60/PMPC with and without sonication, respectively. This result suggests that C60/PMPC shows a sonodynamic effect, which demonstrates its potential application in SDT.