Atmospheric Pressure Plasma Jet Application on Human Oral Mucosa Modulates Tissue Regeneration

Abstract

With the development of plasma sources generating nonthermal plasmas at atmo- spheric pressure the applications broaden enormously, especially in the medical field. While earlier applications of physical plasma on biological matter focused on inactivation of mi- croorganisms, the latest studies have revealed a modulation of eukaryotic cells by the same type of plasma. The aim of this study was to elucidate molecular mechanisms triggered by non-thermal plasma in human oral mucosa. Ex vivo biopsies were treated directly with the cold atmospheric pressure plasma jet kinpenMED and analyzed for distinctive markers of proliferation, apopto- sis, DNA damage, and differentiation. Moreover, secreted cytokines and growth factors were measured in the supernatant. These results revealed stimulating effects indicated by proliferation consolidated by secretion of VEGF. We also proved that these effects were mediated into deeper layers of the mucosa, without harming the cells on top of the treated samples. DNA damage de- tected as H2A.X-immunoreactivity was nearly constant between all samples. Our study revealed for the first time that human oral mucosa can be modulated by plasma treat - ment. Molecular markers for both cell damage and proliferation helped to identify the mecha- nisms triggered by plasma treatment. Moreover, our results strengthen a safe application of the kinpenMED on human oral tissue. Further studies on diseased skin are being performed in order to proceed towards a safe introduction of plasma medicine into the clinics.