Effects of air transient spark discharge and helium plasma jet on water, bacteria, cells, and biomolecules

Abstract

Atmospheric pressure DC-driven self-pulsing transient spark (TS) discharge operated in air and pulse-driven dielectric barrier discharge plasma jet (PJ) operated in helium in contact with water solutions were used for inducing chemical effects in water solutions, and the treatment of bacteria (Escherichia coli), mammalian cells (Vero line normal cells, HeLa line cancerous cells), deoxyribonucleic acid (dsDNA), and protein (bovine serum albumin). Two different methods of water solution supply were used in the TS: water electrode system and water spray system. The effects of both TS systems and the PJ were compared, as well as a direct exposure of the solution to the discharge with an indirect exposure to the discharge activated gas flow. The chemical analysis of water solutions was performed by using colorimetric methods of UV-VIS absorption spectrophotometry. The bactericidal effects of the discharges on bacteria were evaluated by standard microbiological plate count method. Viability, apoptosis and cell cycle were assessed in normal and cancerous cells. Viability of cells was evaluated by trypan blue exclusion test, apoptosis by Annexin V-FITC/propidium iodide assay, and cell cycle progression by propidium iodide/RNase test. The effect of the discharges on deoxyribonucleic acid and protein were evaluated by fluorescence and UV absorption spectroscopy. The results of bacterial and mammalian cell viability, apoptosis, and cell cycle clearly show that cold plasma can inactivate bacteria and selectively target cancerous cells, which is very important for possible future development of new plasma therapeutic strategies in biomedicine. The authors found that all investigated bio-effects were stronger with the air TS discharge than with the He PJ, even in indirect exposure.

Mechanistic insights into the impact of Cold Atmospheric Pressure Plasma on human epithelial cell lines

“…This may explain why they are less susceptible to plasma induced depolarization. Previous studies reported that plasma-induced free radicals affect the pH of the media resulting in cell death2223. Because we used PBS as buffering agent we did not observe these changes.…”

Effects of plasma activated water on wheat: Germination, growth parameters, photosynthetic pigments, soluble protein content, and antioxidant enzymes activity

“…The distance between the electrodes was 1 cm. Deionized water (DW) or tap water (TW) was supplied via narrow channel in the inclined plane electrode and circulated by a peristaltic pump with a constant flow rate (14 ml/min) to provide repetitive contact of water with the discharge . Transient spark discharge (TS), a self‐pulsing repetitive streamer to spark transition discharge was used to activate water .…”

Time Behaviour of Helium Atmospheric Pressure Plasma Jet Electrical and Optical Parameters

“…They involve sterilization and decontamination of liquids, medical surfaces, implants or skin; influences over cellular processes: wound healing, dermatological diseases, cancer cells targeting; dentistry and related applications and treatment of seeds or vegetal tissues [2]. Cancer treatment is certainly one major topic of research, due to the fact that preliminary results of different groups indicate that selectivity may be achieved under specific plasma treatment conditions [3,4].…”