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Cold atmospheric plasma (CAP) has been shown to be beneficial in various medical fields such as wound healing, oncology or dentistry. A prominent effect induced by CAP is the boost of microcirculation in human skin tissue. Being a complex cocktail of physical and chemically reactive components, the mechanisms by which CAP enhances microcirculation still remain unclear. Thus, this study aims to identify relevant CAP components involved in stimulation of dermal microcirculation. In a comparative approach, the application of the same CAP source was modified in such a way that three different treatment modalities could be realized, each with a characteristic composition of electrical current flow and concentration of reactive species. Microcirculation parameters oxygen saturation (StO2), tissue hemoglobin index, near-infrared perfusion index and tissue water index were recorded before and after each treatment on the lateral proximal left arm of 10 healthy volunteers by means of hyperspectral imaging. The maximum microcirculatory response to CAP was observed when all components were allowed to interact with skin tissue (standard treatment). In contrast, no upregulation was found as soon as electric currents and fields had been removed from the effective component spectrum. Application of the CAP source at reduced concentrations of reactive species compared to standard treatment led to significant but less pronounced enhancement of dermal microcirculation. The findings of this study indicate that a synergistic interplay of all CAP components promotes microcirculation in dermal tissue most effectively. Moreover, the findings support the hypothesis that electric currents and fields play a key role in enabling microcirculation boost whereas availability of reactive species in the gas phase is associated with the intensity of the tissue response to CAP treatment. [ABSTRACT FROM AUTHOR]

The application of cold atmospheric plasma (CAP) in cancer therapy has recently received extensive attention. However, researchers have mainly studied the effects of CAP on plasma-irradiated cancer cells and have not determined whether CAP affects surrounding or distant non-irradiated cancer cells. Here, the viability and intracellular reactive oxygen species levels of plasma-irradiated and non-irradiated cancer cells were monitored in vitro. Our results showed that CAP may induce plasma-irradiated cancer cells (A549 cells, A375 cells, J82 cells and HT29 cells) to secrete soluble factors into the cell culture medium, which can transmit plasma-induced anticancer effects from plasma-irradiated cancer cells to non-irradiated cancer cells. Our research confirmed that plasma-induced anticancer effects can be transmitted between cancer cells. [ABSTRACT FROM AUTHOR]

Plasma medicine is a field that utilizes reactive species generated from atmospheric low-temperature plasmas for applications such as sterilization, blood coagulation, and cancer therapy. Commercial plasma devices are available for wound healing, but research on the chemical modifications induced by these plasmas is scarce. This study explores the chemical modifications in hemoglobin when exposed to a helium plasma dielectric barrier discharge, with the aim of explaining the potential mechanisms through which it contributes to blood coagulation and enhances wound healing. Optical microscopy of cold atmospheric plasma (CAP) treated whole capillary blood showed an increase in red blood cell (RBC) size and the formation of rouleaux structures. The treatment of whole blood leads to hemolysis of RBCs and the release of intracellular protein content. We then treated purified hemoglobin protein at physiological concentrations, which led to the formation of aggregates that could be observed using ion mobility mass spectrometry (IM–MS), size exclusion chromatography, and optical microscopy. The aggregates formed fibril-like structures as observed using atomic force microscopy. The formation of hemoglobin aggregates is hypothesized to be the result of new intermolecular interactions formed following the CAP-mediated protein oxidation. We studied the changes to hemoglobin structure after treatment with a CAP using high-resolution MS and found that the hemoglobin subunits are oxidized with the addition of at least 4 oxygen atoms each. The intact tetrameric hemoglobin structure remains unchanged; however, the monomeric and dimeric proteins adopt a more compact structure, as observed by IM–MS. We propose that CAP treatment of fresh blood leads to hemolysis, and that the extracellular protein, primarily hemoglobin, is oxidized leading to the formation of aggregates. [ABSTRACT FROM AUTHOR]

Efficient and biologically safe mode of cold atmospheric plasma jet (CAPJ) is crucial for the development of CAPJ-based anticancer therapy. In the experiment and numerical simulations, by changing the pulse duration of a positive-pulsed (PP) voltage, we found the optimal CAPJ modes with a regular streamer propagation and a maximum discharge current at a temperature T < 42 ∘C. These CAPJs substantially suppressed the viability of cancer cells. To enhance a cytotoxic effect of CAPJ treatment, gold nanoparticles (NPs) were added to the cells before and after the CAPJ exposure. Combination of CAPJ, generated with the PP voltage, and gold NPs decreased the viability of NCI-H23 epithelial-like lung adenocarcinoma, A549 lung adenocarcinoma, BrCCh4e-134 breast adenocarcinoma and uMel1 uveal melanoma cells. Polyethylene glycol-modified NPs with attached fluorescent labels were used to visualize the uptake of NPs. We demonstrated that NPs efficiently entered the cells when were added to the cells just before CAPJ exposure or up to two hours afterwards. The efficiency of NPs penetration into cells positively correlated with the induced cytotoxic effect: it was maximal when NPs was added to cells right before or immediately after CAPJ exposure. Summarizing, the treatment with optimal CAPJ modes in combination with modified NPs, bearing the cancer-addressed molecules and therapeutics may be the next strategy of strengthening the CAPJ-based antitumor approaches. [ABSTRACT FROM AUTHOR]

When mature Arabidopsis thaliana seeds are dormant, their germination is prevented in apparently favorable conditions. This primary dormancy can be released during seed dry storage through a process called after-ripening whose duration can last several months. To reduce this delay, cold atmospheric plasmas (CAPs) can be used as sources of reactive oxygen species (ROS) capable of inducing heterogeneous chemical reactions. While CAP are known to stimulate the germination of various seed species, the relationship between CAP treatments and the amorphous solid state of dry seeds remains unexplored. Here, we demonstrate that seed dormancy can be alleviated using a cold plasma of ambient air and that this alleviation can be amplified for seeds with high water-content (typically 30%DW) or seeds heated at 60 °C during plasma treatment. Differential scanning micro-calorimetry shows that these characteristics control the glassy/rubbery state of the seed cytoplasm. This technique indicates also that a glass transition to the rubbery state strengthens the CAP effects to alleviate seed dormancy. We propose that lower cytoplasmic viscosity can promote the oxidative signaling induced by CAP which, in turn, improves the germination process. [ABSTRACT FROM AUTHOR]