On the penetration of reactive oxygen and nitrogen species generated by a plasma jet into and through mice skin with/without stratum corneum

In this work, reactive oxygen and nitrogen species (RONS) generated by a plasma jet penetrating through and left in the skin after the plasma treatment are measured, and the effects of stratum corneum (SC) on the penetration of the RONS are also investigated. It is found that the RONS generated by the plasma jet can penetrate through the skin, and that the penetration of some kinds of the RONS could be enhanced significantly by tape stripping the SC layer of the skin. Further investigations find that the typical reactive oxygen species, including OH, O-1(2), O-3, and H2O2, cannot penetrate through the mice skin at all (under the detection limit) no matter whether the SC layer of the skin is present or not, where the thickness of the mice skin is about 200-300 mu m. This result is very different from the experimental results obtained from the muscle tissue model and gelatin model. Finally, it is found that high concentrations of long-lived RONS (H2O2, NO2-, and NO3-) are left in the skin after the plasma treatment, which means that the plasma treatment could have a long-time scale therapy effect. This finding is important for the applications of plasma medicine. Published under license by AIP Publishing.