Fig. 4: In vitro sensor measurements and correlation to cellular markers in cold atmospheric plasma (CAP)-exposed HaCaT cells.

a Experimental setup for CAP treated cells (pink) in a 24-well plate. All measurements were performed in 500 µL phosphate-buffered saline (PBS). All data points are plotted (black, diamond) for each treatment time, with the statistical mean (clear, squares), median (black, line in the center of box plot), interquartile ranges (box range: 25–75th percentile of data set), and outer legs of each box (lower 5th percentile and upper 95th percentile of data set) being showcased. Outliers are shown above or below the outer legs. b, c H₂O₂ sensor (n = 12; n = 11 for 5 and 15 s, 4 biological replicates) and oxidation-reduction potential (ORP) voltage readings (n = 9, 3 biological replicates) were taken before (Before scratch) and immediately after a scratch (0 s) of the cell monolayer. Cells were then treated with suboptimal (5 s), optimal (10 s), and excessive (15 s) CAP doses. d, e MitoSOX+ (n = 8, 3 biological replicates) and Ki67+cells (n = 9, 3 biological replicates) were enumerated after no CAP (0 s) or treatment with suboptimal (5 s), optimal (10 s), and excessive (15 s) CAP doses to measure oxidative stress responses and cell proliferation, respectively. Statistical differences between 0 s and treatment groups are identified by: ns, not significant; *p < 0.05; **p < 0.01. Exact p values can be found in Supplemental Data 1. One-way ANOVA with Tukey’s post-hoc test was used.