Cold Atmospheric Plasma Disrupts Microbial Wound Bioburden: In Vitro, Porcine MRSA Biofilm, and Clinical Fluorescence Evidence from Bench to Bedside

Background: Biofilm-associated microbial burden is a major barrier to wound healing and is increasingly difficult to control in the era of antimicrobial resistance. This translational study evaluated the antimicrobial performance and tissue compatibility of a commercially available large-area cold atmospheric plasma (CAP) system (CPTpatch®/CPTcube®; Coldplasmatech GmbH, Greifswald, Germany) across in vitro, porcine, and clinical patient settings. Methods: CAP was tested against seven wound-relevant bacterial species, including multidrug-resistant strains, and the fungus Candida albicans in vitro, in two porcine MRSA-infected deep dermal wound models, and in a clinical service-evaluation cohort of 20 chronic lower-limb wounds in 14 patients; 17 wounds had evaluable longitudinal MolecuLight® (Toronto, ON, Canada) fluorescence series. Results: In vitro, CAP induced rapid multi-log killing across the bacterial panel and showed a marked antifungal effect against C. albicans. In porcine MRSA wounds, CAP reduced bacterial burden versus sham by 1.65, 1.89, and 2.04 log10 CFU/g on Days 4, 8, and 11, equivalent to 97.8%, 98.7%, and 99.1% reductions. In a 72-h post-inoculation MRSA biofilm model, the strongest 5×/week regimen achieved 2.51 log10 (99.69%) and 3.18 log10 (99.93%) reductions versus baseline after 2- and 4-min CAP exposures, respectively. Clinically, twice-weekly CAP was associated with a significant decline in MolecuLight® fluorescence grades over 5 weeks (p < 0.001); effective surface disinfection at 5 weeks was observed in 16/17 evaluable wounds. Conclusions: From bench to bedside, the investigated CAP system delivered rapid broad-spectrum antimicrobial activity, reduced MRSA burden in biofilm-infected porcine wounds, and was associated with clinically measurable suppression of wound surface bioburden while remaining tissue-sparing. These findings support further controlled studies to define clinical benefit in wound care.