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

## TL;DR

This study shows that combining cold plasma and hydrogen peroxide is more effective at killing bacteria on tissue-like surfaces than using either treatment alone.

## Contribution

The study introduces a method to evaluate combined cold plasma and hydrogen peroxide treatments on a wound-like tissue model.

## Key findings

- Cold plasma alone achieves 7 log reduction on agar but only 0.88 log on chicken tissue.
- Hydrogen peroxide alone yields 1.06 log reduction on chicken tissue.
- Combining cold plasma and hydrogen peroxide increases bacterial inactivation to 1.69 log reduction.

## Abstract

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 Escherichia coli (E. coli) 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 E. coli 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.

•Cold plasma (CP) and hydrogen peroxide exhibited bactericidal properties independently.•Bacterial reduction on tissue proved more difficult than inactivation on an agar surface.•A 10-min treatment of CP and hydrogen peroxide, in combination, demonstrated an increase in bacterial inactivation.

Cold plasma (CP) and hydrogen peroxide exhibited bactericidal properties independently.

Bacterial reduction on tissue proved more difficult than inactivation on an agar surface.

A 10-min treatment of CP and hydrogen peroxide, in combination, demonstrated an increase in bacterial inactivation.