Foam pad outperforms gauze at stripping wound biofilms in pig-skin model

A two-sided foam pad with distinct loosening and absorptive surfaces removed more than 90% of viable bacteria from laboratory-grown wound biofilms in an ex vivo porcine wound model, consistently outperforming traditional cotton gauze, according to a peer-reviewed study published in Scientific Reports. The research compared four mechanical cleansing and debridement tools head-to-head under standardised conditions. The team, led by Christopher Doherty and Andrew J. McBain, cultivated dual-species biofilms of Staphylococcus aureus and Pseudomonas aeruginosa on porcine skin.

The devices tested were a one-sided straight monofilament fibre pad, a one-sided looped monofilament fibre pad, the two-sided foam pad, and conventional cotton gauze. To eliminate operator variability, debridement was performed with a mechanical simulator that applied identical conditions across all trials. The researchers evaluated the tools at three stages of biofilm maturity: 24 hours, 72 hours and seven days after inoculation.

They also ran repeated debridement schedules over seven days, performing the procedure once, twice or three times, to simulate outpatient dressing-change schedules. Removal was quantified by colony counting to measure viable bacteria remaining per wound, and by viability mapping to visualise where living cells persisted on the wound surface. In the single-debridement experiments, both the one-sided looped monofilament fibre pad and the two-sided foam pad removed significantly more biofilm than gauze at the 24-hour time point.

The foam pad, however, was the only device to maintain its performance across biofilm ages: it achieved greater than 90% model-derived reduction in viable colony-forming units per wound at every single-debridement time point, and its removal was significantly greater than gauze at 24, 72 and 168 hours. Viability staining with PrestoBlue supported the colony-count data, showing corresponding reductions in the PrestoBlue-positive wound-surface coverage after treatment with the foam pad. The repeated-debridement experiments reinforced the pattern.

The two-sided foam pad sustained greater than 90% model-derived reduction in viable bacteria and significantly outperformed gauze under every debridement schedule tested, whether the wounds were treated once, twice or three times over the seven days. Effect-size analysis underscored the magnitude of the differences. Hedges' g values for the foam pad relative to gauze and to the single-sided devices frequently exceeded 2.0, indicating pronounced effects under the predefined interpretation thresholds used by the authors.

The findings are model-derived results. The experiments used an ex vivo porcine wound model with laboratory-cultured dual-species biofilms rather than infected human wounds, and debridement was performed by a mechanical simulator rather than clinicians, so the results cannot be directly translated into clinical outcomes without further work. Nevertheless, by standardising force, motion, biofilm maturity and measurement methods, the researchers isolated device performance as the variable of interest.

Subject of Research: Comparative biofilm removal performance of four mechanical wound cleansing and debridement devices in an ex vivo porcine wound model

Article Title: Evaluation of the comparative biofilm removal properties of four cleansing and debridement tools, in an ex vivo porcine wound model

Article References: Doherty, C., Baqader, S., Mercer, S., & McBain, A. J. (2026). Evaluation of the comparative biofilm removal properties of four cleansing and debridement tools, in an ex vivo porcine wound model. Scientific Reports. https://doi.org/10.1038/s41598-026-75044-8

Image Credits: AI Generated

DOI: 10.1038/s41598-026-75044-8

Keywords: wound care, biofilm, debridement, porcine wound model, Staphylococcus aureus, Pseudomonas aeruginosa, Scientific Reports, mechanical cleansing, foam pad, cotton gauze, ex vivo model, Evaluation