Safety and efficacy of the Plasma Directed Electron Beam (PDEB ™) - implications for enhanced wound healing treatment in military operational medicine and beyond

Abstract

Introduction: Wound healing presents a critical challenge in military operational medicine and combat casualty care, especially for soldiers in high-risk environments such as combat zones and training exercises. In these scenarios, wounds often result from bullets, shrapnel, burns, and blasts, affecting soft tissue, bone, and internal organs, and are frequently contaminated with hazardous substances like debris and bacteria. Limited resources in these environments make rapid and effective treatment difficult, often leading to delayed medical care and poorer healing outcomes. Emerging technologies like nonthermal plasma (NTP), also known as cold plasma, may provide superior wound healing treatment efficacy in these environments, owing to the ability to effectively kill pathogens, stimulate tissue regeneration, and minimize collateral damage compared to traditional methods. The Plasma Directed Electron Beam™ (PDEB™), an innovative advancement in nonthermal plasma research, shows promise in addressing these challenges. Materials and Methods: The antibiofilm efficacy of the PDEB™ was investigated on Acinetobacter baumannii and Streptococcus mutans. Cytotoxicity was assessed using primary human epithelial cells and TR146 cells, immortalized epithelial cells. Cell proliferation assays, immunoblotting, and lactate dehydrogenase (LDH) release were evaluated. Results: Our study demonstrates the effectiveness of the PDEB™ handheld in inhibiting the growth of bacterial pathogens implicated in biofilms. Acinetobacter baumannii and Streptococcus mutans showed zones of inhibition starting at lower power levels, achieving complete inhibition at 14 watts (W) and 7W respectively for 90-120 seconds. The safety of the PDEB™ was assessed through cell proliferation assays using human epithelial cells and semi-confluent TR146 cells, which were exposed to similar conditions as the bacterial assays. TR146 cells showed negligible differences in cleaved caspase 3 levels compared to controls. Cytotoxicity and apoptosis assays further confirmed the safety of PDEB™, as lactate dehydrogenase (LDH) release in epithelial cells and activated caspase 3 levels in cell extracts were comparable to untreated and helium-treated cells, indicating minimal cellular damage. Conclusion: The PDEB™ handheld, a first-generation device, has demonstrated significant efficacy in inhibiting the growth of bacteria. Concurrently, its application on human epithelial cells has shown encouraging safety profiles. These findings align with the effectiveness of traditional nonthermal plasma devices, positioning the PDEB™ as a viable and promising option for wound healing applications in Combat Casualty Care and Military Operational Medicine.