Hydrogen peroxide: A central player in physical plasma-induced oxidative stress in human blood cells

Abstract

Plasma medicine is an interdisciplinary field and recent clinical studies showed benefits of topical plasma application to chronic wounds. Whereas most investigations have focused on plasma-skin cell interaction, immune cells are omnipresent in most tissues as well. They not only elicit specific immune responses but also regulate inflammation, which is central in healing and regeneration. Plasma generates short-lived radicals and species in the gas phase. Mechanisms of plasma-cell interactions are not fully understood but it is hypothesized that reactive oxygen and nitrogen species (RONS) mediate effects of plasma on cells. In this study human blood cells were investigated after cold atmospheric plasma treatment with regard to oxidation and viability. Plasma generates hydrogen peroxide (H2O2) and the responses were similar in cells treated with concentration-matched H2O2. Both treatments gave an equivalent reduction in viability and this was completely abrogated if catalase was added prior to plasma exposure. Further, five oxidation probes were utilized and fluorescence increase was observed in plasma-treated cells. Dye-dependent addition of catalase diminished most but not all of the probe fluorescence, assigning H2O2 a dominant but not exclusive role in cellular oxidation by plasma. Investigations for other species revealed generation of nitrite and formation of 3-nitrotyrosine but not 3-chlorotyrosine after plasma treatment indicating presence of RNS which may contribute to cellular redox changes observed. Together, these results will help to clarify how oxidative stress associates with physical plasma treatment in wound relevant cells.

Hydrogen Peroxide: A Potential Wound Therapeutic Target

“…Nonthermal atmospheric plasma (NAP) has been used in the clinical setting to accelerate wound healing [69] . Some changes exerted by NAP were abolished by catalase and the cells' responses to NAP treatment are similar to incubating in H 2 O 2 in a similar concentration [69,70] , as exemplified by the plasma-induced profound extracellular trap formation (NET), which can be inhibited by the presence of catalase. However, adding an equivalent concentration of H 2 O 2 cannot induce NET [71] .…”

A Comparison of Floating-Electrode DBD and kINPen Jet: Plasma Parameters to Achieve Similar Growth Reduction in Colon Cancer Cells Under Standardized Conditions

“…Many types have been identified in plasma-treated liquids in the past years [72]. For the kINPen plasma jet, this includes for example nitrite, nitrate, hydrogen peroxide, superoxide, hydroxyl radical, peroxynitrite, and singlet oxygen [72][73][74]. Plasma gas phase analysis suggests the presence of many others [75][76][77].…”

Identification of the biologically active liquid chemistry induced by a nonthermal atmospheric pressure plasma jet

“…The approach enabled a quick and reproducible treatment of cells in a 96 well plate and allowed an easy correlation with chemical assays. In vitro/ex vivo findings in different model systems of Bekeschus, 38 Schmidt, 39 and Wende et al 21 further indicated, that a separate treatment of liquids provokes the same biological effect as a direct treatment at least for the kinpen. The same effect has been observed for the plasma jet studied in this work (see Fig.…”