Safety and efficiency evaluation of an innovative plasma jet array in argon using gas switching technology

Abstract Wound healing is an important and still-challenging task in modern medicine. In particular, therapeutic options for treating chronic wounds linked to diseases like diabetes are limited. One promising approach is the application of cold atmospheric plasma (CAP) via medical plasma jets (PJs) or dielectric barrier discharges to specifically stimulate the healing process of non-healing wounds. However, limitations occur regarding the treatment area in the case of PJs. Thus, an innovative PJ array system (PJAS) was developed to extend the capabilities of established PJs in treating large areas like chronic wounds. Utilizing patented gas switching technology, the PJAS aims to provide effective treatment over larger areas within shorter application times. Determination of performance and safety indicators included measurements of leakage current, temperature, starch–potassium iodide tests, suspension tests, cell viability tests and inhibition zone assays. Values are compared with a medical PJ system, the kINPen ® MED. Findings indicated that the PJAS showed enhanced efficacy compared to present medical PJs. Systematic analyses of leakage current, neutral gas temperature, and emission spectra confirmed the device’s safety. A two-step observation was found in the effluent temperature profile of the PJAS with a possible relation to free jet physics and argon-enriched zones. Starch–potassium iodide experiments revealed that the PJAS system oxidizes an area up to twice the size treated by the PJ under the same conditions. Antimicrobial suspension tests indicated an inactivation ranging from 2.1 to 4.9 orders of magnitude, while inhibition zone assays resulted in an up to 14-fold increase in the effective area for S. aureus and to a twofold increase for C. albicans in direct comparison to PJ. Additionally, treatment of human fibroblast cells indicated preserved cell vitality for 30 s of plasma exposure. Overall, the PJAS has the potential to become a promising therapeutic option for chronic wound treatment.