There are literary evidences that low-intensity ultrasound can enhance its damaging effect on living cells in presence of certain substances - sensitizers. Such substances in the most works were photosensitizers - the compounds that capable for light-depending generation of cytotoxic products, in particular singlet oxygen. The physicochemical mechanisms of cell sensitization to ultrasound, that is, mechanisms of so-called "sonodynamic effect," are not clear. There are some evidences in favor of the hypothesis that reactive oxygen species participate in this process. The purpose of this work was to reproduce the sonodynamic effect, as well as to elucidate its possible cellular-molecular mechanisms. As the cell-sensitizing substances for ultrasound of 2.53 MHz or 44 kHz two photosensitizers - methylene blue and aluminophthalocyanine Photosens, as well as Fe3O4 nanoparticles were used. Ultrasound of 2.53 MHz, which did not cause cavitation phenomena in the experimental chamber, did not lead to the formation of hydrogen peroxide, singlet oxygen, and did not affect cells survival, either alone or in combination with the photosensitizers. Ultrasound of 44 kHz itself, causing pronounced cavitation phenomena, raised the percentage of necrotic cells, and produced hydrogen peroxide. The addition of Fe3O4 nanoparticles, but not photosensitizers, had increased ultrasound-induced necrosis of cells by one-third. Herewith, there was no increase in the production of hydrogen peroxide, but the formation of singlet oxygen was observed.
sonodynamic effect, cavitation, reactive oxygen species
1. Posudin Yu.I. Lazernaya fotobiologiya. K.: Vischa shkola, 1989. [Posudin Yu.I. Laser photobiology. Kiev: Vishcha shkola, 1989. (In Russ.)]
2. Dougherty T.J., Gomer C.J., Henderson B.W., Jori G., Kessel D., Korbelik M., Moan J., Peng Q. Photodynamic therapy. J Natl Cancer Inst., 1998, vol. 90, pp. 889-905.
3. Costley D., Mc Ewan C., Fowley C., McHale A. P., Atchison J., Nomikou N., Callan J. F. Treating cancer with sonodynamic therapy: A review. International Journal of Hyperthermia, 2015, vol. 31, pp. 107-117.
4. McHale A.P., Callan J.F., Nomikou N., Fowley C., Callan B. Sonodynamic Therapy: Concept, Mechanism and Application to Cancer Treatment. Advances in Experimental Medicine and Biology, 2016, vol. 880, pp. 429-450.
5. Margulis M.A. Osnovy zvukohimii, M.: Vyssh. shk., 1984. [Margulis M.A. Fundamentals of sonochemistry, Moskva, Vysshaya shkola, 1984. (In Russ.)]
