Chemical dosimetry of an indirect exposure non-thermal plasma device

Abstract

Summary form only given. Interest in the use of non-thermal plasmas in the biomedical setting is rapidly growing. Potential applications of such devices range from instrument sterilization to clinical therapy. One of the largest hurdles to the implementation of nonthermal plasmas, specifically in regard to patient exposure, is the relatively poor understanding of the chemical processes taking place. Recent research has focused intensely on the dynamic chemical cocktail associated with specific discharge configurations. Our group recently detailed the ability to control chemical species created by our device through modifying operating parameters, namely humidity1. Specifically, we demonstrated our device's capability to deliver the short-lived hydroxyl radical to treatment sites at a distance of over a meter from the plasma discharge. This recent development of our remote design allows for potential user-defined specificity in both concentration and flavor of chemical exposure to the treatment environment. Introduction of non-thermal plasma devices to the clinical setting, specifically in the United States, will inevitably require a certain degree of therapeutic control. We report on the in vitro “plasma dosimetry” related to the application of our device. Control of the device effluent's chemical makeup allows for parameterization of treatment-related variables like the ratio of inactivation or DNA oxidation between prokaryotic and eukaryotic species. Building on previous work using electron spin resonance spectroscopy to enumerate free radicals delivered to our treatment site, we demonstrate the potential for a therapeutic window of operation. Such regulation provides the potential to tune non-thermal plasma based devices with regard to the contamination or infection being treated.