| AVS 65th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Tuesday Sessions |
| Session PS+PB-TuM |
| Session: | Plasma Medicine |
| Presenter: | Kenji Ishikawa, Nagoya University, Japan |
| Authors: | K. Ishikawa, Nagoya University, Japan Y. Hosoi, Nagoya University, Japan D. Kanno, Nagoya University, Japan Y. Kurokawa, Nagoya University, Japan H. Tanaka, Nagoya University, Japan M. Mizuno, Nagoya University, Japan F. Kikkawa, Nagoya University, Japan M. Hori, Nagoya University, Japan |
| Correspondent: | Click to Email |
Selective killing of cancer cells incubated in non-equilibrium atmospheric pressure plasma (NEAPP)-activated medium (PAM) has been reported.[1] This antitumor effect revealed by involvement of reactive oxygen and nitrogen species (RONS) in PAM.[2] The effect was also found in plasma-activated lactate in Ringer's solution (Lactec), so called as PAL.[3] We found that the cancer cells incubated in the PAL received lesser oxidative stress than that of the PAM.[3] A cause of intracellular oxidation with respect to the RONS reactions has been studied by nuclear magnetic resonance (NMR) analysis of organic substances in the Lactec solution.
From the NMR measurements, reactive organic acids, that is, plasma activated lactate (LA) involved pyruvic acid (PA) and acetic acid (AA)-like components in the PAL were detected. The plasma activated organic acids act potentially as antitumor agents other than RONS.
Furthermore, NEAPPs irradiated to fullerenol. The plasma irradiated fullerenol demonstrated a cytotoxic effect on cells. The PF was modified by the plasma irradiation, arising carbonyl groups, ether bonds, and intercalated nitrate anion. Endocytosis of the PF induced to apoptotic cell death and generated intracellular RONS on cells cultured in the PF-added cell culture medium.
1 mL of fullerenol-added water (1.6 mM) was irradiated by the NEAPP (Ar 2 slm) for 3 min. Precipitates of the PF were collected by drying water at 70°C for 1 hr. The collected PF dissolved again into 50 μM of cell culture media (DMEM). 5 × 103 of HeLa cells were cultured for 24 hr in the PF-added DMEM and the same amount (50 μM) of fullerenol-added DMEM, respectively. Cell viability was evaluated by the MTS assay. Caspase activation and fullerenol permeation of the cell membrane were observed by fluorescent microscopy.
Although the viability of the fullerenol-added DMEM remained at a constant of 110 %, the HeLa cell viability decreased to 70 %, when the cells were incubated in the PF-added DMEM. The cells showed caspase 3/7 activation. The PF activate the caspase cascade pathway to induce apoptosis and permeation of the fullerenol into the cells. Therefore, the fullerenol properties were modified by the plasma-irradiation to enhance the cytotoxicity of PF.
Acknowledgments This study was supported by KAKENHI 24108002.
[1] S. Iseki et al., Appl. Phys. Lett. 100, 113702 (2012).
[2] N. Kurake et al., Arch. Biochem. Biophys. 605, 102 (2016).
[3] H. Tanaka et al., Sci. Rep. 6, 36282 (2016).