Inactivation of Breast Cancer Cells using Nitrogen-Oxygen-Radical-Activated Lactate Ringer's Solution

Plasma-activated lactate Ringer's solution (PAL) has been reported to be able to selectively inactivate various cancer cells against normal cells. However, plasma contains various factors and it has not been clarified which factors in plasma contribute the production of cytotoxicity effects in PAL. To investigate the individual contribution of these species, we employed an equipment that can irradiate only neutral species. Using this, we prepared nitrogen-oxygen-radical-activated lactate Ringer's solution (NORAL). In our previous study, NORAL has been reported to inactivated skin cancer cells. However, the inactivation effect on other cancer cells have not been fully investigated. Therefore, we have evaluated the effectiveness of NORAL on other cancer cells. The flow rates of Ar, N2 and O2 were set at 1.6, 0.12, and 0.48 slm, and the breast cancer cells and normal cells were treated with prepared NORAL. The cell viability of cancer cells was reduced to 19 and 42% using the 1- and 2-fold diluted NORAL whereas that of normal cells was reduced only to 48 and 75%, respectively. These results indicate that electrically neutral radicals are ones of key species for a production of cytotoxic effects in PAL.