ヒラオカ　ワカコ   Hiraoka Wakako   平岡　和佳子    所属   明治大学  理工学部    職種   専任教授
言語種別	英語
発行・発表の年月	2008/02
形態種別	学術雑誌
査読	査読あり
標題	Sonodynamic effect of photosensitizers : The enhancement of cell killing by a radical independent mechanism.
執筆形態	共著(筆頭者)
掲載誌名	Photomedicine and Photobiology
巻・号・頁	29,pp.4-7
著者・共著者	Wakako Hiraoka, Takakshi Kondo.
概要	To clarify the mechanism of the sonodynamic enhancement of cell killing with photosensitizers, we have compared between sonodynamic effect and photodynamic effect with photosensitizers on free radical formation and cell killing. Ultrasound-induced enhancement of killing of human lymphoma U937 cells was shown in photosensitizer dyes; hematoporphyrine, rose bengal, erythrosine B, rhodamine 6G, rhodamine 123 and sulforhodamine B. ESR analysis using 2,2,6,6-tetramethyl-4-piperidone indicated the production of singlet oxygen from photo-irradiated dyes. On the other hand, sonochemical enhancement of generation of reactive oxygen species was not shown in sono-irradiated dyes. ESR-spin trapping using 3,5-dibromo-4-nitrosobenzene sulfonic acid showed carbon-centered radicals in sono-irradiated dyes. However, the dye radicals were not responsible for ultrasound-induced enhancement of cell killing by sensitizers. These results suggest that free radicals are not involved in the enhancement of ultrasound-induced cell killing and that the mechanism of enhancement should be mainly due to certain mechanical stress.