Effects of Cold Atmospheric Plasmas (CAPs) on bacterial and eukaryotic membranes

Cold atmospheric plasmas (CAPs) have shown to efficiently cure bacterial infections without producing harmful side effects. CAPs can be delivered to any biological tissue because of their low heating capacity. The most active species of CAP are ionized and non-ionized vector gas, reactive oxygen and nitrogen species (RONS) and superheated electrons. One of the main targets of CAP activity in bacteria and eukaryotic cells is the cell membrane, and some selectivity towards bacteria seems to arise from this effect. We therefore investigate the effects of CAP on bacterial, eukaryotic and model membranes to determine how selectivity could arise from a membrane related effect. We examine chemical and biophysical changes induced by CAP and how those changes influence cellular homeostasis. We determined that CAP induced the formation of lipid aldehydes in model membranes, depending on the degree of unsaturation. Those species seemed very effective in permeabilizing the membrane compared to lipid peroxides. But not only chemical modifications by RONS seemed to drive CAP activity because we observed that solely the vector gas alone (Argon) was very efficient in reducing packing of model and bacterial membranes. It seems though that there was a synergy between ionized, radical and non-ionized species driving the activity of CAP on membranes.