Antibacterial efficacy of combined atmospheric cold plasma and hydrogen peroxide treatment on a wound surrogate

This study aims to understand the potential combined effects of treating wound-like tissue surfaces with cold plasma (CP) and hydrogen peroxide. We assess how CP treatment generated by a surface dielectric barrier discharge (SDBD) device achieves bacterial inactivation on two test surfaces: agar plates, representing a surface with uniform topology, and muscle tissue from a thin-sliced chicken breast, representing a non-uniform topology mimicking a wound-like surface. A 10-min CP treatment inactivates <i>Escherichia coli (E. coli)</i> with up to 7 log reduction in colony-forming units (CFU) on a smooth agar surface; however, on chicken breast, the same treatment yields a 0.88 log reduction. By comparison, the common antiseptic H₂O₂ (3 %) yields a 1.06 log CFU reduction on chicken breast after 10 min of treatment. Simultaneous treatment with CP and H₂O₂ increases <i>E. coli</i> inactivation to 1.69 log CFU. Bacterial inactivation is less efficient on the chicken tissue than on smooth agar surfaces. Furthermore, the CP-H₂O₂ combination significantly improves bacterial inactivation, which can be further enhanced by extending treatment time. This work demonstrates an approach to evaluating the efficacy of combining CP with liquid antimicrobial treatments on an accessible wound surrogate with complex morphology and biochemistry. This approach has the potential to serve as a fast method to screen candidate treatments before performing animal studies.