## 3 Results and Discussion
### NTP Activated the WNT3A/\(\beta\)-catenin Pathways in HaCaT Cells
(**B**) Count of the number of migrated cells. (**C**) Effect of NAC on protein phosphorylation. (**D**) Quantification of phosphorylated protein expression. Data represent the mean \(\pm\) SD of three independent experiments. * \(p<0.05\), ** \(p<0.01\), *** \(p<0.001\) with ANOVA compared with the control. Studies have shown that cells show different cell states and fates to different concentrations of H\({}_{2}\)O\({}_{2}\)[3,62]. For nerve cells, at levels below 1 nM H\({}_{2}\)O\({}_{2}\), cell growth is slow and development and regeneration are impaired. In addition, the cells tended to be in a resting state with no tendency to proliferate and differentiate. When the nerve cells were exposed to H\({}_{2}\)O\({}_{2}\) in the range of 1-10 nM, the growth of axons and dendrites was promoted. It was mainly because the cells produced oxidative stress under this H\({}_{2}\)O\({}_{2}\) concentration, which stimulated the proliferation and differentiation of cells. In addition, the study also showed that a modest increase in H\({}_{2}\)O\({}_{2}\) concentration (up to about 100 nM) further promoted dendritic growth. Abnormally high H\({}_{2}\)O\({}_{2}\) (more than 100 nM) can lead to the death of nerve cells and tissue degradation [3]. It is well known that the proliferation and migration of HaCaT cells is essential to promote clinical wound healing. In this study, NTP directly acted on HaCaT cells for 10 s or 15 s to promote their proliferation and migration, showing that NTP directly acts on  
Figure 10: Schematic representation of the mechanism by which NTP treatment promoted proliferation and migration of HaCaT cells. ROS produced by low-dose NTP promoted the proliferation and migration of HaCaT cells by promoting the expression of PI3K, AKT, mTOR, ERK, PI3K, Cyclin D1, WNT, and \(\beta\)-catenin. such wounds as clinical diabetic ulcer wounds [11] and burn wounds [41] to promote their healing by promoting the proliferation and migration of HaCaT cells. In addition, results showed that treatment of cells with NTP for 20 s or 25 s inhibited cell proliferation and migration, which also made NTP potentially applicable to diseases such as psoriasis [63] and melanoma [64]. Although the difference was only more than ten seconds, the reaction of cells to it was not the same. The plasma device finally applied to clinical practice must undergo repeated improvement and testing. Our experiment here was only to explore the impact of NTP on the cell level. It was only a preliminary study, which was different from the final clinical application of NTP. In addition, the sensitivity of cells and tissues to plasma is different because tissues also contain many other kinds of cells and substances. NTP treatment of tissues was the result of a comprehensive effect. Therefore, the time for NTP treatment of cells was relatively short, and the time for final treatment of clinical tissues was definitely relatively long. Compared with the characteristics of small discharge intensity and accurate treatment of the plasma jet, the plasma dielectric barrier discharge device we used had the characteristics of large discharge intensity and wide treatment range, and could process multiple samples at the same time [4]. In addition, our current NTP device was an experimental device and was not suitable for use in patients, and further research is required. In the future, we will manufacture an automatic NTP device with a timer, which can provide specific treatment times according to different conditions of diseases, such as wounds or skin diseases, and different treatment areas, and can also target different wound conditions by adjusting other parameters of the device, such as the flow rate of gas, the type of gas, or a mixture of gases in different proportions, so as to provide more accurate treatment. There still are some shortcomings in our experimental results. Next, we need to conduct a large number of animal experiments and clinical trials before NTP can be finally applied to clinical practice.