Surface Microdischarge Plasma for Disinfection

摘要

Cold atmospheric plasma (CAP), with its antibacterial, antiviral, and antifun-gal properties, may offer different applications for medicine and medical technology. Wound care, the treatment of chronic or acute wounds, reflects one of these possible applications, because CAPs can inactivate different kinds of microorganisms, including antibiotic-resistant strains. In this article, we describe the way in which surface micro-discharge (SMD) plasma was investigated to evaluate a safe therapeutic window for wound treatment. We found that SMD plasma provided a significant bactericidal effect without harming skin cells. For testing the bactericidal efficacy of the SMD electrode, we used Escherichia coli as the test strain. To evaluate the response of plasma-treated eukaryotic cells, we used primary human dermal fibroblasts. As reported earlier, SMD plasmas have a unique characteristic in that the plasma chemistry produced in a confined volume can be varied by changing the input power into the plasma: low-input power produces a more reactive oxygen species-based chemistry and high-input power a more reactive nitrogen species. Using this characteristic, bactericidal effect and cell viability were investigated for a wide range of chemical plasma cocktails with different compositions and concentrations of mainly reactive oxygen and nitrogen species. Our results clearly reveal therapeutic plasma conditions wherein a high bactericidal effect and significant cell viability can be achieved simultaneously.