Measurements of Temperature and Relative Concentration of Atomic Oxygen in DBD Plasma for Wound Healing and Sterilization
Abstract
Among emerging biomedical approaches, dielectric barrier discharge (DBD) plasma has shown promise in accelerating wound healing and enhancing sterilization through the production of reactive oxygen and nitrogen species (RONS), which drive tissue regeneration. Recent studies underscore oxygen as a critical factor in radical generation at wound sites, influencing various stages of tissue repair. Consequently, monitoring oxygen concentration and plasma temperature is essential, as both hypoxic and hyperoxic conditions can impede healing. Building on oxygen’s critical role in tissue repair, a helium-based plasma sheet was developed to treat large wound areas more efficiently than conventional plasma jets. Two-photon absorption laser-induced fluorescence (TALIF) was employed to evaluate how varying plasma input parameters affect the relative concentration of atomic oxygen in helium plasma. Results show that 0.1 slpm oxygen added to helium plasma increased atomic oxygen fourfold as voltage doubled compared to helium-only plasma. Optical emission spectroscopy with SPECAIR modeling was used to estimate plasma temperature components as oxygen was added to the helium plasma to confirm that plasma still retained its nonequilibrium (Te ~ Tv > Tr ~ Tt). The antimicrobial efficacy of plasma was evaluated by exposing Escherichia coli K-12 colonies to helium-oxygen plasma, achieving an ~ 82% reduction in bacterial levels with 0.1 slpm added oxygen. Overall, this work demonstrates a promising pathway to optimize wound healing using nonthermal plasma technologies.
