title: Investigation of the antimicrobial activity at safe levels for eukaryotic cells of a low power atmospheric pressure inductively coupled plasma source.
abstract: Low power atmospheric pressure inductively coupled thermal plasma sources integrated with a quenching device (cold ICP) for the efficient production of biologically active agents have been recently developed for potential biomedical applications. In the present work, in vitro experiments aimed at assessing the decontamination potential of a cold ICP source were carried out on bacteria typically associated with chronic wounds and designed to represent a realistic wound environment; further in vitro experiments were performed to investigate the effects of plasma-irradiated physiological saline solution on eukaryotic cells viability. A thorough characterization of the plasma source and process, for what concerns ultraviolet (UV) radiation and nitric oxide production as well as the variation of pH and the generation of nitrates and nitrites in the treated liquid media, was carried out to garner fundamental insights that could help the interpretation of biological experiments. Direct plasma treatment of bacterial cells, performed at safe level of UV radiation, induces a relevant decontamination, both on agar plate and in physiological saline solution, after just 2 min of treatment. Furthermore, the indirect treatment of eukaryotic cells, carried out by covering them with physiological saline solution irradiated by plasma, in the same conditions selected for the direct treatment of bacterial cells does not show any noticeable adverse effect to their viability. Some considerations regarding the role of the UV radiation on the decontamination potential of bacterial cells and the viability of the eukaryotic ones will be presented. Moreover, the effects of pH variation, nitrate and nitrite concentrations of the plasma-irradiated physiological saline solution on the decontamination of bacterial suspension and on the viability of eukaryotic cells subjected to the indirect treatment will be discussed. The obtained results will be used to optimize the design of the ICP source for an effective production of reactive species, while keeping effluent temperature and UV radiation at values compatible with biomedical treatments.
authors.affiliation: Department of Industrial Engineering (D.I.N.), Alma Mater Studiorum-Università di Bologna, Via Terracini 24, 40123 Bologna, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Barbieri
authors.affiliation: Industrial Research Centre for Advanced Mechanics and Materials (C.I.R.I.-M.A.M.), Alma Mater Studiorum-Università di Bologna, Via Saragozza 8, 40123 Bologna, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Boselli
authors.affiliation: Industrial Research Centre for Advanced Mechanics and Materials (C.I.R.I.-M.A.M.), Alma Mater Studiorum-Università di Bologna, Via Saragozza 8, 40123 Bologna, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cavrini
authors.affiliation: Department of Industrial Engineering (D.I.N.) and Industrial Research Centre for Advanced Mechanics and Materials (C.I.R.I.-M.A.M.), Alma Mater Studiorum-Università di Bologna, Via Saragozza 8, 40123 Bologna, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Colombo
authors.affiliation: Department of Industrial Engineering (D.I.N.), Alma Mater Studiorum-Università di Bologna, Via Saragozza 8, 40123 Bologna, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Gherardi
authors.affiliation: Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Alma Mater Studiorum-Università di Bologna, Via Massarenti 9, 40183 Bologna, Italy.
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Landini
authors.affiliation: Department of Industrial Engineering (D.I.N.), Alma Mater Studiorum-Università di Bologna, Via Saragozza 8, 40123 Bologna, Italy.
authors.forename: Romolo
authors.initials: R
authors.lastname: Laurita
authors.affiliation: Department of Industrial Engineering (D.I.N.), Alma Mater Studiorum-Università di Bologna, Via Saragozza 8, 40123 Bologna, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Liguori
authors.affiliation: Department of Industrial Engineering (D.I.N.), Alma Mater Studiorum-Università di Bologna, Via Saragozza 8, 40123 Bologna, Italy.
authors.forename: Augusto
authors.initials: A
authors.lastname: Stancampiano
mesh_terms: D000818:Animals; D001274:Atmospheric Pressure; D002470:Cell Survival / Q000187:drug effects; D004203:Disinfection / Q000379:methods*; D005057:Eukaryotic Cells / Q000187:drug effects / Q000502:physiology; D006801:Humans; D050296:Microbial Viability / Q000528:radiation effects*; D058626:Plasma Gases; D012965:Sodium Chloride / Q000737:chemistry / Q000528:radiation effects* / Q000633:toxicity; D014466:Ultraviolet Rays
chemical_list: D058626:Plasma Gases; D012965:Sodium Chloride