Gas-liquid interfacial plasmas producing reactive species for cell membrane permeabilization.

Gas-liquid interfacial atmospheric-pressure plasma jets (GLI-APPJ) are used medically for plasma-induced cell-membrane permeabilization. In an attempt to identify the dominant factors induced by GLI-APPJ responsible for enhancing cell-membrane permeability, the concentration and distribution of plasma-produced reactive species in the gas and liquid phase regions are measured. These reactive species are classified in terms of their life-span: long-lived (e.g., HO), short-lived (e.g., O), and extremely-short-lived (e.g., OH). The concentration of plasma-produced OH in the liquid phase region decreases with an increase in solution thickness (<1 mm), and plasma-induced cell-membrane permeabilization is found to decay markedly as the thickness of the solution increases. Furthermore, the horizontally center-localized distribution of OH, resulting from the center-peaked distribution of OH in the gas phase region, corresponds with the distribution of the permeabilized cells upon APPJ irradiation, whereas the overall plasma-produced oxidizing species such as HO in solution exhibit a doughnut-shaped horizontal distribution. These results suggest that OH is likely one of the dominant factors responsible for plasma-induced cell-membrane permeabilization.