Influence of Skin Temperature Increase During Helium Plasma Jet Irradiation

In recently, atmosphere pressure plasma jet (APPJ) has been widely applied to the research field of life science, because APPJ can generate reactive species. For effective use of the plasma, there is needs to deliver the reactive species into biological targets e.g., cell and / or tissue. In our previous collaborative studies, we have shown how plasma generated reactive species are delivered into solid tumor underneath skin. Interestingly, we observed unusual skin condition after a long-term direct plasma irradiation in another unpublished study. We speculated such unusual skin condition is due to increase of skin temperature during plasma irradiation. Aim of this study is how the unusual skin condition to be formed from the point of view of surface skin temperature. In this study, we used live nude mouse, mouse skin (or chicken skin) and 3D printed mouse model for irradiation targets. We investigated correlation between increase of surface temperature on the skin and plasma bullet current. These results indicate that the increase in skin surface temperature during plasma irradiation is due to the current of the plasma bullets. Also, we estimated possible burn area from experiment result. However, as a conclusion, the possibility of burns was ruled out from our pathology results.