title: Safety aspects of atmospheric pressure helium plasma jet operation on skin: In vivo study on mouse skin.
abstract: Biomedical applications of plasma require its efficacy for specific purposes and equally importantly its safety. Herein the safety aspects of cold plasma created with simple atmospheric pressure plasma jet produced with helium gas and electrode discharge are evaluated in skin damage on mouse, at different duration of exposure and gas flow rates. The extent of skin damage and treatments are systematically evaluated using stereomicroscope, labelling with fluorescent dyes, histology, infrared imaging and optical emission spectroscopy. The analyses reveal early and late skin damages as a consequence of plasma treatment, and are attributed to direct and indirect effects of plasma. The results indicate that direct skin damage progresses with longer treatment time and increasing gas flow rates which reflect changes in plasma properties. With increasing flow rates, the temperature on treated skin grows and the RONS formation rises. The direct effects were plasma treatment dependent, whereas the disclosed late-secondary effects were more independent on discharge parameters and related to diffusion of RONS species. Thermal effects and skin heating are related to plasma-coupling properties and are separated from the effects of other RONS. It is demonstrated that cumulative topical treatment with helium plasma jet could lead to skin damage. How these damages can be mitigated is discussed in order to provide guidance, when using atmospheric pressure plasma jets for skin treatments.
authors.affiliation: Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Spela
authors.initials: S
authors.lastname: Kos
authors.affiliation: Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Tanja
authors.initials: T
authors.lastname: Blagus
authors.affiliation: Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia.|Faculty of Health Sciences, University of Primorska, Izola, Slovenia.
authors.forename: Maja
authors.initials: M
authors.lastname: Cemazar
authors.affiliation: Jozef Stefan Institute, Ljubljana, Slovenia.
authors.forename: Gregor
authors.initials: G
authors.lastname: Filipic
authors.affiliation: Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Gregor
authors.initials: G
authors.lastname: Sersa
authors.affiliation: Jozef Stefan Institute, Ljubljana, Slovenia.
authors.forename: Uros
authors.initials: U
authors.lastname: Cvelbar
mesh_terms: D000818:Animals; D001274:Atmospheric Pressure; D002057:Burns, Chemical / Q000209:etiology* / Q000473:pathology; D005260:Female; D006371:Helium / Q000009:adverse effects*; D006358:Hot Temperature / Q000009:adverse effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D058626:Plasma Gases / Q000009:adverse effects*; D012867:Skin / Q000187:drug effects* / Q000293:injuries / Q000473:pathology
chemical_list: D058626:Plasma Gases; D006371:Helium