Cold Microwave Plasma Jets for Wound Healing: Antimicrobial Efficacy, Mechanisms and Changes in Microbial Cells
Summary: Researchers at Brno University of Technology (Czech Republic), in collaboration with partners in Prague, Brno, and Lublin (Poland), have published a comprehensive investigation of cold atmospheric plasma (CAP) as a non-thermal antimicrobial strategy for wound care applications, appearing in Scientific Reports on March 6, 2026. The study was motivated by the escalating global burden of antibiotic-resistant microorganisms and the need for effective non-antibiotic decontamination methods. Using a custom-built cold microwave plasma jet, the team demonstrated effective inactivation of four clinically relevant organisms: Staphylococcus epidermidis, Escherichia coli, Cutibacterium acnes, and Nakaseomyces glabratus (formerly Candida glabrata). A critical mechanistic finding was that reactive oxygen and nitrogen species (RONS) — not UV radiation — are primarily responsible for microbial inactivation, established through colorimetric agent experiments and enclosed vs. open-air environment comparisons. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed progressive morphological and intracellular changes in yeast cells following plasma treatment, including localized cell wall thinning and perforation, vacuole enlargement, enhanced vesicle formation, protoplast aggregation, and leakage of intracellular content — consistent with RONS-driven oxidative damage. Optimal treatment parameters balancing antimicrobial efficacy with safety for living tissue were also established, a prerequisite for clinical translation. The study builds on the group’s prior work on plasma sources for biomedical applications and contributes to the growing field of plasma medicine.
Key Highlights:
- Cold microwave plasma jets confirmed effective against S. epidermidis, E. coli, C. acnes, and N. glabratus — organisms spanning bacteria and fungi commonly implicated in wound infection
- RONS — not UV radiation — are the primary inactivation mechanism, confirmed through enclosed/open-air comparisons and colorimetric assays
- TEM analysis reveals progressive yeast cell wall thinning and perforation, vacuole enlargement, vesicle formation, and intracellular content leakage — a detailed ultrastructural map of plasma-induced cell death
- Optimal treatment parameters established balancing antimicrobial efficacy with tissue safety — a critical step toward clinical use
- Dedicated to the memory of co-author František Krčma, who constructed the MW plasma sources and secured funding; he passed away prior to publication
- Relevance: Non-antibiotic wound decontamination technology with growing preclinical evidence base — relevant as antibiotic resistance increasingly complicates chronic wound management
Keywords: cold atmospheric plasma, plasma medicine, wound infection antimicrobial, antibiotic resistance wound, wound biofilm, RONS wound healing
Kristína Trebulová Veronika Loupová Barbora Chobotská Lukáš Kletzander Přemysl Menčík Zdenka Kozáková Jan Hrudka Joanna Pawlat Pavel Kulich František Krčma (deceased)