Spatially resolved optical emission spectroscopy of a helium plasma jet and its effects on wound healing rate in a diabetic murine model

Abstract

A spatially resolved characterization of the active species generated in a pure helium plasma plume was performed using optical emission spectroscopy techniques. A qualitative assessment of the radiative species was conducted under various experimental conditions to determine the ideal flow rate and distance along the plume for maximal species production. Nitrogen radicals dominated the emission in the spectra, though measurable amounts of oxygen and OH were also observed, with a minimal radiative contribution from the He carrier gas. Radiative species were maximized 25–30 mm distal to the outflow orifice of the plasma generator. A diabetic mouse model was then utilized to examine the effects of this pure helium plasma on the healing rates of large-area, full-thickness skin wounds. A total of 80 mice were included and were subjected to one of several treatment regimens: 30 seconds twice daily, 60 seconds twice daily, 90 seconds once daily, and helium gas control. Digital photographs were taken daily, and wound surface areas were quantified using image analysis software. Curves were then fit to daily wound surface areas to determine healing rates. Wounds healed significantly faster following plasma treatment. The maximum effect was obtained with 60-second treatments applied twice daily.