Helium Generated Cold Plasma Finely Regulates Activation of Human Fibroblast-Like Primary Cells

Abstract

Non-thermal atmospheric pressure plasmas are being developed for a wide range of health care applications, including wound healing. However in order to exploit the potential of plasma for clinical applications, the understanding of the mechanisms involved in plasma-induced activation of fibroblasts, the cells active in the healing process, is mandatory. In this study, the role of helium generated plasma in the tissue repairing process was investigated in cultured human fibroblast-like primary cells, and specifically in hepatic stellate cells and intestinal subepithelial myofibroblasts. Five minutes after treatment, plasma induced formation of reactive oxygen species (ROS) in cultured cells, as assessed by flow cytometric analysis of fluorescence-activated 2′,7′-dichlorofluorescein diacetate probe. Plasma-induced intracellular ROS were characterized by lower concentrations and shorter half-lives with respect to hydrogen peroxide-induced ROS. Moreover ROS generated by plasma treatment increased the expression of peroxisome proliferator activated receptor (PPAR)-γ, nuclear receptor that modulates the inflammatory responses. Plasma exposure promoted wound healing in an in vitro model and induced fibroblast migration and proliferation, as demonstrated, respectively, by trans-well assay and partitioning between daughter cells of carboxyfluorescein diacetate succinimidyl ester fluorescent dye. Plasma-induced fibroblast migration and proliferation were found to be ROS-dependent as cellular incubation with antioxidant agents (e.g. N-acetyl L-cysteine) cancelled the biological effects. This study provides evidence that helium generated plasma promotes proliferation and migration in liver and intestinal fibroblast-like primary cells mainly by increasing intracellular ROS levels. Since plasma-evoked ROS are time-restricted and elicit the PPAR-γ anti-inflammatory molecular pathway, this strategy ensures precise regulation of human fibroblast activation and can be considered a valid therapeutic approach for liver and gut lesions.

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

“…A combination of different plasma properties is also possible as seen with bacteria [81][82][83]. Corroborating results of the jet plasma in the present work, presence and concentration of H 2 O 2 strongly correlated with cytotoxic effects of the kINPen [84][85][86] and other jet and DBD plasma sources [87][88][89][90], especially plasma-treated liquids [91][92][93]. Yet, in a helium/oxygen plasma jet, we previously demonstrated cytotoxicity correlating with short-lived species supporting the generation of hypochlorous acid in aqueous media [94].…”

Cold Physical Plasmas in the Field of Hygiene—Relevance, Significance, and Future Applications

“…In addition to the plasma's antiseptic activity, some cells are eliminated by plasma‐induced apoptosis, and the proliferation and migration of fibroblasts and keratinocytes as well as angiogenesis is promoted . Mild inflammatory stimuli in, for example, immune cells and skin cells, may help the chronic wound to transit from stagnation into the phase of acute inflammation, to subsequently mediate wound healing. As plasma is also active against biofilms and antibiotic‐resistant bacteria, it may support wound contracture after successful decolonization as recently demonstrated .…”

Characterization of a plasma source for biomedical applications by electrical, optical, and chemical measurements

“…Furthermore, as regards the cells composing the corneal surface, a very high viability was found after the plasma treatment, with no relevant DNA damage . It is also interesting to observe that the same plasma source displayed effects which could be of interest for wound healing and in the context of cancer treatment, where in vitro studies have shown the capability of the helium afterglow emitted by the source to selectively induce apoptosis in cancer cells while preserving the healthy ones, either alone or in combination with a molecule which enhances the level of intracellular reactive oxygen and nitrogen species (RONS) . Given this body of beneficial biological effects, a careful physical and chemical characterization of the plasma source appeared mandatory, in order to gain a better understanding of the processes through which the biological action is obtained.…”