ABSTRACT
The direct and indirect bactericidal effects of dielectric barrier discharge (DBD) cold atmospheric-pressure microplasma in an air and plasma jet generated in an argon-oxygen gas mixture was investigated on Staphylococcus aureus and Cutibacterium acnes. An AC power supply was used to generate plasma at relatively low discharge voltages (0.9-2.4 kV) and frequency (27-30 kHz). Cultured bacteria were cultivated at a serial dilution of 10-5, then exposed to direct microplasma treatment and indirect treatment through plasma-activated water (PAW). The obtained results revealed that these methods of bacterial inactivation showed a 2 and 1 log reduction in the number of survived CFU/mL with direct treatment being the most effective means of treatment at just 3 min using air. UV-Vis spectroscopy confirmed that an increase in treatment time at 1.2% O2, 98.8% Ar caused a decrease in O2 concentration in the water as well as a decrease in absorbance of the peaks at 210 nm, which are attributed NO2- and NO3- concentration in the water, termed denitratification and denitritification in the treated water, respectively.
Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Atmospheric Pressure , Plasma Gases/chemistry , Plasma Gases/pharmacology , Microbial Sensitivity Tests , Ozone/analysis , Ozone/chemistry , Reactive Nitrogen Species/chemistry , Reactive Oxygen Species/chemistry , Staphylococcus aureus/drug effects , Sterilization/methods , Water/chemistryABSTRACT
A study of the transdermal delivery of Cyclosporine A by atmospheric plasma irradiation was realized on the epidermal layer of the Hairless Yucatan micropig. Drug flux and the amount of drug penetrated through the skin were determined by a Franz cell diffusion experiment. After treatment of the skin by atmospheric plasma jet or microplasma dielectric barrier discharge, an increase in the permeability of the skin was observed. The authors did not observe drug penetration for samples that were not treated with plasma. There was no significant difference between treatments of skin by plasma jet or microplasma dielectric barrier discharge. Drug flux increased to its maximal value up to 3 h after the drug application, and then it decreased. This phenomenon could indicate a temporal effect of plasma on skin. A pharmacokinetic two-compartment model was developed to estimate the possibility of using plasma drug delivery of Cyclosporine A in medical praxis. Our model showed that it is possible to use this technique if a suitable treatment area and concentration of applied drug are chosen.
