Evaluation of a Novel Peptide-Based Dressing on Infected Wounds with Pseudomonas aeruginosa Using a Partial Thickness Porcine Wound Model

Antimicrobial peptides are well-known for their antimicrobial and antibiofilm properties in vitro, however their efficacy in vivo is limited. 1 The goal of this study was to determine the ability of collagen-based dressings containing antimicrobial host-defense peptides (HDPs) to reduce Pseudomonas aeruginosa in a porcine partial thickness wound model.2,3

Deep partial thickness wounds were created, and wounds were inoculated with Pseudomonas aeruginosa ATCC 27312 (PA). The wounds were covered for 24 hours to allow for biofilm formation. After 24 hours, 3 wounds were recovered for baseline counts prior to treatment. The remaining wounds were randomly assigned to one of nine treatment groups: 1) Untreated Control wounds, 2) Dressing Alone, 3) Dressing + Peptide 1* 10mg, 4) Dressing + Peptide 1* 5mg, 5) Dressing + Peptide 1* 10mg + Antimicrobial, 6) Dressing + Peptide 1* 5mg + Antimicrobial, 7) Dressing Alone + Antimicrobial, 8) Dressing + Peptide 2* + Antimicrobial or 9) Positive Control Silver Sulfadiazine. On days 3 and 6 post-treatment wounds were assessed for microbiology analysis. Wounds treated with Dressing Alone + Antimicrobial, showed the lowest bacterial counts compared with baseline and untreated wounds on both assessment days 3.87± 0.18 and 3.67± 0.30 Log CFU/ml, respectively.

Those values represent more than 99.98 percentage of reduction. Treated wounds with Dressing + Peptide 1 10mg + Antimicrobial resulted in the second-best treatment with reductions compared to untreated and baseline more than 99.90%. Peptide 1 and Peptide 2 combined with the antimicrobial agent resulted in PA reductions of more than 99.00% compared with the positive control tested (Silver Sulfadiazine).

This pilot study suggests that this antimicrobial peptide dressing may have important clinical implications, additional animals are currently being conducted to substantiate these findings and evaluate its effect on wound healing.

Acknowledgement: This study was supported by DOD Grant (W81XWH-18-2-0028) awarded to iFyber, LLC* iFyber, LLC peptide formulation