Selective Cytotoxicity of Lung Cancer Cells-A549 and H1299-Induced by Ringer's Lactate Solution Activated by a Non-thermal Air Plasma Jet Device, Nightingale®

Plasma technology has recently been one of the potential candidates for the targeted treatment of cancers. In this work, Nightingale((R)), a non-thermal air plasma jet device, was used to activate lactated Ringer's injection (LRI) for the in vitro inactivation of lung cancer cells-A549 and H1299. The optimal treatment condition and its effects on the cell cytotoxicity of lung cancer cells were evaluated. Optical emission spectroscopy (OES) and gas detection results indicated gas phase reactive oxygen and nitrogen species (RONS) can be controlled and precisely calculated from plasma dissipated power. For plasma-activated LRI (PA-LRI), concentrations of H2O2, NO3-, and NO2-, as well as their shelf lives, were investigated. Two-hour treatment of PA-LRI on A549 and H1299 cells resulted in 92% and 70% cell death, respectively. While the non-cancerous cell, human lung fibroblast (HLF), was not affected neither in terms of cell death or morphological change. To elucidate the mechanisms of the tumor cell cytotoxicity induced by PA-LRI, common active species generated in PA-LRI (H2O2, NO2-, NO3-) were tested. Results showed that H2O2 alone can induce 72% of cell death, compared to PA-LRI, while it was 19% and 2% for NO2- and NO3- respectively. The addition of catalase, which degrades H2O2, reduced cell death induced by PA-LRI and H2O2 to 9% and 6%, respectively. These suggest H2O2 is the main player in PA-LRI-induced lung cancer cell death in vitro. Our discoveries not only benefit the effective usage of plasma-activated LRI but also the applications of plasma technology in medical fields.

Automated summary

In this study, a non-thermal air plasma jet device was used to activate lactated Ringer's injection (LRI) for the in vitro inactivation of lung cancer cells. The results showed that plasma-activated LRI was able to effectively kill lung cancer cells while leaving non-cancerous cells unaffected. These findings not only contribute to the effective usage of plasma-activated LRI, but also advance the applications of plasma technology in the medical field.