Development of Rapid and Economic In Vitro Assay and Biorelevant Ex Vivo Biofilm Inhibition Wound Model to Test the Antibacterial Efficacy of Wound Dressings.

Chronic wounds are a major healthcare problem, consuming resources globally and necessitating innovative wound dressing development. All antimicrobial wound dressings must be tested for safety and antibacterial effectiveness prior to patient use. This study aimed to develop a rapid, economical in vitro assay and biorelevant ex vivo wound biofilm model on porcine skin to test the antibacterial efficacy of antimicrobial wound dressings. The methods were validated using five commercially available wound dressings and experimental electrospun (ES) wound dressing containing chloramphenicol in polycaprolactone and polyethylene oxide fibres (PCL/PEO/CAM). An in vitro assay was used to assess the growth inhibition, killing efficacy, and dressing sterility against multiple bacterial strains and inoculum sizes. Ex vivo models using porcine skin were used to evaluate biofilm inhibition with dressings on top of or inside infected wounds. The in vitro assay allowed rapid initial screening, whilst ex vivo models provided more biorelevant conditions for understanding the efficacy in wound-mimicking environments. The assay and model are suitable for rapid evaluation of antimicrobial efficacy before animal studies and clinical trials. Using various commercially available wound dressings alongside novel dressings for validation ensures that the method is broadly applicable. The antibacterial efficacy of commercial antimicrobial wound dressings and experimental ES PCL/PEO/CAM fibre mat was confirmed. This study highlights the importance of using multiple complementary assays and models to comprehensively assess antimicrobial wound dressing materials.