A Novel In Vitro Scrubber Model for Evaluating Wound Cleansing on Biofilms

Chronic wounds are a significant burden on patients and hospitals globally, with all exhibiting high microbial loading and biofilm. Wound cleansing is critical for removing foreign contaminants, damaged tissue and opportunistic pathogens, allowing for improved healing. This study addresses the need for a standardised in vitro preclinical model for comparing the efficacy of antimicrobial wound cleansing solutions with mechanical disruption on biofilms. A novel model was developed to emulate cleaning practises whilst standardising pressure applied and scrubbing forces applied to the wound bed. Using wounded porcine explants, microbial biofilms were formed on the surface before exposure to varying physical parameters and cleaning solutions. The results showed that both increased pressure and scrubbing duration had a positive impact on biofilm removal, demonstrating > 1 log reduction in microbial levels. The model was able to show the significant difference in cleaning solutions between saline and an antimicrobial-based solution (HClO), > 4.5 log reduction, whilst under identical conditions. Confocal laser microscopy, using fluorescent viability stains, provided supporting evidence of biofilm disruption using gauze. The model's adaptability and versatility help to provide clinically relevant in vitro evidence and effective comparisons of wound cleansing agents on biofilms through the standardisation of different cleaning techniques.