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

The effectiveness of four mechanical debridement devices for removing ex vivo porcine wound biofilms was assessed. Devices comprised a one-sided straight monofilament fibre pad, a one-sided looped monofilament fibre pad, a two-sided foam pad with distinct loosening and absorptive surfaces (TSFP), and traditional cotton gauze. Dual-species Staphylococcus aureus / Pseudomonas aeruginosa biofilms were cultivated in an ex vivo porcine wound model. Debridement was standardised using a mechanical simulator and performed at a single time point (24 h, 72 h, or 7 d post-inoculation) to represent differing biofilm maturities, or repeatedly over seven days (once, twice, or three times) to simulate outpatient dressing-change schedules. Biofilm removal was quantified using colony counting and viability mapping. In the model-derived percentage-removal analysis following single debridements, OSLMP and TSFP demonstrated significantly greater removal than gauze at 24 h. TSFP consistently achieved > 90% model-derived reduction in viable CFU/wound across all single-debridement time points and demonstrated significantly greater removal than gauze at 24, 72 and 168 h. PrestoBlue staining revealed corresponding reductions in PrestoBlue-positive wound-surface coverage. Following repeated debridements, TSFP maintained > 90% model-derived reduction in viable CFU/wound and demonstrated significantly greater removal than gauze following each debridement schedule. Hedges’ g effect sizes frequently exceeded 2.0 for TSFP relative to gauze and the single-sided devices, indicating pronounced effects under the predefined interpretation thresholds.