The potential applications of low temperature plasma (LTP) in wound healing have aroused the concern of many researchers. In this study, an argon atmospheric pressure plasma jet was applied to generate LTP for treatment of murine fibroblast cell (L929) cultured in vitro to investigate the effect of NF-κB pathway on fibroblast proliferation. The results showed that, compared with the control, L929 cells treated with plasma for less than 20 s had significant increases of proliferation; the productions of intracellular ROS, O2 − and NO increased with prolongation of LTP treatment time; NF-κB pathway was activated by LTP in a proper dose range, and the expression of cyclinD1 in LTP-treated cells increased with the same trend as cell proliferation. After RNA interference to block p65 expression, with the same treatment time, RNAi-treated cells proliferated more slowly and expressed less cyclinD1 than normal cells. Furthermore, pretreatment with N-acetyl-L-cysteine (NAC) markedly prevented the plasma-induced changes in cells. In conclusion, the proliferation of L929 cells induced by LTP was closely related to NF-κB signaling pathway, which might be activated by appropriate level of intracellular ROS. These novel findings can provide some theoretical reference of LTP inducing cell proliferation and promoting wound healing.

Low-temperature plasma (LTP) has shown great promise in wound healing, although the underlying mechanism remains poorly understood. In the present study, an argon atmospheric pressure plasma jet was employed to treat L929 murine fibroblasts cultured in vitro and skin wounds in BALB/c mice. The in vitro analysis revealed that treatment of fibroblasts with LTP for 15 s resulted in a significant increase in cell proliferation, secretion of epidermal growth factor (EGF) and transforming growth factor-βi (TGF-βi), production of intracellular reactive oxygen species (ROS), and the percentage of cells in S phase, protein expression of phosphorylated p65 (P-p65) and cyclinD1, but a noted decrease in the protein expression of inhibitor kappa B (IκB). The in vitro experiments demonstrated that 30-s LTP treatment enhanced the number of fibroblasts and the ability of collagen synthesis, while 50-s treatment led to the opposite outcomes. These results suggested that LTP treatment promotes the fibroblast proliferation in wound healing by inducing the generation of ROS, upregulating the expression of P-p65, downregulating the expression of IκB, and activating the NF-κB signaling pathway and consequently altering cell cycle progression (increased DNA synthesis in S phage).

An argon atmospheric pressure plasma jet was employed to treat L929 murine fibroblasts cultured in vitro. Experimental results showed that, compared with the control cells, the treatment of fibroblasts with 15 s of plasma led to a significant increase of cell viability and collagen synthesis, while the treatment of 25 s plasma resulted in a remarkable decrease. Exploration of related mechanisms suggested that cold plasma could up-regulate CyclinD1 gene expression and down-regulate p27 gene expression at a low dose, while it could down-regulate CyclinD1 expression and up-regulate p27 expression at a higher dose, thus altering the cell cycle progression, and then affecting cell viability and collagen synthesis of fibroblasts.

The potential antitumor application of low-temperature plasma (LTP) has attracted wide attention from researchers. The mechanism of plasma antitumor action may be related to LTP-induced reactive oxygen and nitrogen species. The aim of this study was to identify the apoptotic effects of plasma on melanoma cells (B16) in vivo and in vitro. For this purpose, a helium atmospheric-pressure plasma jet (APPJ) was used to generate the plasma-activated saline and medium (PAS and PAM). The PAS was injected subcutaneously to treat B16-tumor bearing mice in vivo and the PAM was used to treat B16 cells in vitro. Catalase (CAT) was added into the PAM to degrade H 2 O 2 as the intervention group. The tumor nodules' weight, cryosections, B16 cell viability, apoptosis, DNA damage, p53 pathway-related protein and the concentration of H 2 O 2 in PAM were detected. The in vivo results showed that PAS could inhibit tumor growth and induce apoptosis. The in vitro results revealed the concentration of H 2 O 2 in the PAM increased as LTP treatment time was longer, while the cell viability decreased as APPJ irradiation time was increased. Flow cytometry results showed that, compared with the control group, all PAM treatment groups showed a higher apoptotic rate. A single cell gel assay and an 8-OHdG assay showed that the PAM could induce DNA damage. A western blotting assay indicated that the PAM could increase the expressions of p53, p53induced gene 8 protein, PIG3, cytoplasmic cytochrome c, cleaved-caspase-9 and -3. However, CAT could alleviate all these changes effectively. These findings suggested that plasma exerted an apoptotic effect on B16 cells mainly by activating the p53/PIGs/caspase pathway.

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