Facilitating Wound Healing with an Enhanced Antimicrobial Hydrofiber Dressing – an in Vivo Study

Aim: To use an in vivo colonized wound model to quantify the effect of a new enhanced antimicrobial Hydrofiber dressing (AAA) on bioburden levels and wound healing rates.

Method: Pseudomonas aeruginosa and Staphylococcus aureus colonization was established in a well-characterized in vivo full-thickness wound model over several days. Wounds were then dressed over 12 days with either (i) AAA; or (ii) a PHMB gauze dressing. Dressings were changed every other day and bacterial counts were performed at day 0, 4 and 8. At day 12, wounds were excised and healing was assessed using quantitative microscopy.

Results & Discussion: Bacterial counts for P. aeruginosa and S. aureus had increased for both dressings by day 4, but by day 8, AAA had resulted in a 50% reduction in microbial counts overall. In contrast, the PHMB gauze resulted in a 45% increase in biofilm counts overall. At day 12, the epithelial gap for AAA-managed wounds was half the size of that of PHMB gauze-managed wounds (p=0.028). Granulation tissue formation was 19% greater in AAA-managed wounds (p=0.021). The cosmetic appearance of AAA-managed wounds was notably improved over PHMB gauze-managed wounds. In a challenging, mixed-species, in vivo colonized wound model, the AAA dressing was significantly superior to PHMB gauze at reducing wound bioburden and facilitating wound healing.

Conclusion: These findings suggest that AAA may be an effective dressing for facilitating healing in wounds that are impeded, or are at risk of being impeded, by bioburden.