Where Do Ros Go? Oxidation Cascades In Melanoma Exposed To Cold Physical Plasma

In plasma medicine, physical atmospheric cold plasma is used for application in therapeutic appliances such as wound healing or decontamination of infected skin.[1] Over the last decade, plasmas became a valuable research tool for cancer therapy.[2] Many groups have not only reported an efficient killing of cancer cells with plasma but also a selectivity of the killing of malignant over non-malignant cells.[3] Yet, following the trajectories of plasma-derived reactive oxygen and nitrogen species has only begun to be explored. First modeling studies suggest an important role of lipid peroxidation and phosphatidylserine content in the cell membrane.[4] Using fluorescent reporter dyes, many groups have reported cytosolic oxidation following plasma treatment. Some groups claim that DNA double-stranded breaks are a direct product of reactive species deposition by plasmas.[5] Using human melanoma cells, the purpose of this work was to study in detail how different cell compartments are affected reactive species derived the atmospheric pressure argon plasma jet kINPen. Using confocal laser scanning microscopy, several versions of fluorescent reporter dyes were used to assess oxidation qualitatively and quantitatively. We hope our study to contribute to the understanding how plasma-generated reactive species penetrate cells and affect their behavior and viability, especially for future plasma cancer treatment.