(LR-037) The Antimicrobial and Wound Healing Effects of an Occlusive Cold Plasma Foil Using a Deep Dermal Wound Porcine Model

Joel Gil, BS – Sr. Manager, Research Laboratory, Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine; Michael Solis, MBA – Sr. Research Associate 1, Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine; Roger Cassagnol, BS – Research Assistant, Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine; Ivan Jozic, PhD – Research Associate Professor, Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine; Carsten Mahrenholz, MSc, MBA – Founder & CEO, COLDPLASMATECH GmbH; Stephen Davis, BS – Research Professor, Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine

Introduction: Methicillin resistant Staphylococcus aureus (MRSA) is associated with chronic wounds and remains a prevalent pathogen with emerging resistances.¹ Cold atmospheric plasma therapy has been demonstrated to improve wound healing in early clinical evaluation and other works have reported antimicrobial activity.^2,3 The efficacy of advanced large area cold plasma therapy (CPT) device was investigated in this study against MRSA wound infections. A porcine model was used because of the similarities to human skin.⁴

Methods: Sixty deep dermal wounds (22mm x 22mm x 3mm) were created on the paravertebral and thoracic areas of two animals.⁵ Wounds were inoculated with 10⁶ CFU/mL of MRSA USA300 and covered to allow for 72h biofilm formation before treatment application. In the first animal, cold plasma therapy was compared to sham dressings and in the second animal, treatment regimen duration and frequency were evaluated. Microbiological baseline was recovered from designated wounds prior to treatment application. Remaining wounds were recovered for histology and microbiology analysis on assessment days 4, 8 or 11.

Results:

The bioburden of MRSA USA300 in wounds was reduced significantly (p ≤ 0.05) by cold plasma therapy compared to sham dressings at all assessment times. The reductions ranged from 97.8% to 99.1% on day 4 to day 11. The results of the treatment regimens for the second animal demonstrate that cold plasma therapy reduces MRSA in a dose-dependent manner with greater reductions observed for longer treatment durations and more frequent treatment applications. Treatment application for 4 minutes, 5x/week reduced MRSA counts by 99.87% compared to untreated wounds. No detrimental effects on healing were observed in the histological analysis of cold plasma treated wounds.

Discussion:

This study provides compelling evidence that large area cold atmospheric plasma therapy effectively reduces pathogenic biofilms and S. aureus burden while remaining safe for the healing process. The therapy's ability to tackle a significant public health challenge like MRSA, coupled with a lack of observed resistance development, highlights its potential as a novel antimicrobial strategy. Additional animals to substantiate these findings and examine potential mechanisms of action are warranted.