Abstract
INTRODUCTION: Diabetes mellitus is a chronic disease that can disrupt physiologic wound healing. Medical gas plasma technology produces therapeutic reactive species that support wound healing. OBJECTIVE: Previous studies have shown that increasing the transcriptional activity of the redox regulator nuclear factor erythroid 2-related factor 2 (Nrf2) in diabetic models can improve insulin sensitivity, reduce blood glucose levels, and ameliorate diabetic complications. However, the therapeutic potential and mechanisms of action of gas plasma have not been addressed in this context. METHODS: Full-thickness dermal ear wounds were created in a preclinical mouse model of type II diabetes and compared with a native wild-type strain of C57BL/6 mice. First, the formation of reactive species in the plasma gas phase was determined by optical emission spectroscopy. Second, qPCR, protein expression, and inflammation analysis by cytokine secretion were performed to confirm the transcriptional results. Finally, qPCR and cytokine profiling were conducted to measure the effects of gas plasma in patient wound samples. RESULTS: Repeated in vivo treatment with medical gas plasma supported wound healing, e.g., re-epithelialization, in both sexes. Gas plasma-stimulated changes in Nrf2 signaling associated with downstream targets were supported by the evidence of impaired wound healing in Nrf2 knockout mice. In addition, gas plasma treatment significantly affected inflammation by modulating local and systemic cytokine levels. In vivo, treatment of human diabetic wounds underscored the involvement of Nrf2 signaling in protecting against oxidative stress, as assessed by qPCR. The cytokine signature of human diabetic wounds outlined different response patterns among patients after a single exposure, while inflammatory mediators were consistently reduced after repeated plasma treatment. CONCLUSIONS: The present finding of accelerated wound healing by the Nrf2 activator underlines the high potential of medical gas plasma therapy in non-diabetic and diabetic wound healing.