Figure 1.
APNT DBD plasma shows growth inhibitory effect in cancer cells.
(a) Schematic diagram of an atmospheric pressure non-thermal dielectric barrier discharge (APNT DBD) plasma device. (b) Metabolic viability (%) of cells after plasma treatment was compared after 24 h incubation. (c) Colony forming capacity and clonogenic survival of exponentially growing T98G, SNU80, KB and HEK293 cells. Results from four independent experiments are shown as mean ± SD, and Student’s t-test was performed to controls (*p<0.05 and **p<0.01).
Figure 2.
The cell counts (relative to control) showed exposure/incubation time-dependent death rate.
KB cells underwent more severe loss than SNU80 and HEK293 by APNT DBD plasma treatment. Results from four independent experiments are shown as mean ± SD, and Student’s t-test was performed to controls (*p<0.05 and **p<0.01).
Figure 3.
APNT plasma effects on morphological structure of T98G cancer and HEK293 cells.
(a) Cell morphology analyzed by scanning electron microscope (SEM). Cells have blebbing and clear changes in morphology on their outer surface 24 h after plasma treatment. (b) Summary of cellular morphological parameters (length and width).
Figure 4.
Analyses of the size variability of T98G and HEK293 cells.
(a) and (b) show the frequency distribution of length and width, respectively, in the T98G cell population. (c) and (d) shows the frequency distribution of length and width, respectively, in the HEK293 cell population.
Figure 5.
Induction of ROS in APNT DBD plasma treated cells.
(a) T98G, SNU80, KB and HEK293 cells were treated with the oxidation-sensitive fluorescent probe 2,7-dichlorodihydrofluorescein diacetate (H2DCFDA) for detection of total ROS, (b) detection of H2O2 level (in µM) in cells observed at 24 h after exposure. In (a) and (b), all fluorescence levels were expressed as fluorescence intensity (FL intensity). Results from four independent experiments are shown as mean ± SD, and Student’s t-test was performed to controls (*p<0.05 and **p<0.01).
Figure 6.
Changes in redox indicators due to APNT plasma exposure.
(a) Detection of GSH/GSSG levels in cells. (b) NADP+/NADPH ratio in cells levels of NADP+ and NADPH were measured using a standard prepared for NADPH. The ratio of NADP+ and NADPH was plotted as a function of treatment time. (c) Total antioxidant activity (TAOA) was assessed in APNT plasma treated cells. Results from four independent experiments are shown as mean ± SD, and Student’s t-test was performed to controls (*p<0.05 and **p<0.01).
Figure 7.
Involvement of caspase activation and loss in mitochondrial membrane potential during apoptosis.
(a) APNT plasma induced activation of caspase-3/7 of human glioblastoma (T98G) and a non-malignant (HEK293) cell lines. (b) APNT plasma affects mitochondrial membrane potential of T98G, SNU80, KB and HEK293 cells. (c) Flow cytometric plot of mitochondrial membrane potential in cells, using Mito Flow rhodamine dye. Results from four independent experiments are shown as mean ± SD, and Student’s t-test was performed to controls (*p<0.05 and **p<0.01).
Figure 8.
Analysis of APNT induced cell death (apoptosis).
Flow cytometry data of Annexin V and PI staining of human T98G, SNU80, KB and HEK293 cells after plasma treatment. Apoptosis of each cell was evaluated after 24± SD, and Student’s t-test was performed to controls (*p<0.05 and **p<0.01).