Fig. 1.
ROS/RNS profile of kINPen plasma and cellular oxidation. (a) Schematic overview of ROS/RNS characterization in plasma gas and liquid phase. (b) Optical emission spectroscopy (OES) profile of the kINPen plasma jet indicating the presence of hydroxyl radicals (.OH), molecular nitrogen (N2) as part of the second positive system of nitrogen, and excited argon (Ar) peaks (n = 10). (c) pH in gas plasma-oxidized NaCl (n = 3). (d-f) Quantification of hydrogen peroxide (H2O2; d), nitrite (NO2–; e), and nitrate (NO3–; f) in gas plasma-oxidized liquids immediately (bars) and 1 h after gas plasma treatment in the presence (circle) or absence (triangle) of cancer cells (n = 3); bar graphs show mean ± standard error of the mean (SEM). (g) Representative images of intracellular ROS evaluated via DCF fluorescence. (h) Quantitative image analysis of DCF fluorescence intensities immediately, 6 h, and 12 h after gas plasma treatment in malignant (I) RT-112, (II) SCaBER, and (III) T24 cells, and (IV) CLS cells normalized to control (n = 3); graphs show mean and biological replicates; statistical analysis was performed using one-way analysis of variance (ANOVA) with Dunnett post-hoc testing (***p < 0.001). Scale bar = 100 µm.