2120. Activity of a Hypochlorous Acid-Generating Electrochemical Bandage for Treating Experimental Murine Wounds Infected with Pseudomonas aeruginosa
Authors: Fleming Derek , Özdemir Dilara , Ortero Judith Alvarez , Anoy Md Monzurul , Karau Melissa J , Bozyel Ibrahim , Schuetz Audrey N , Greenwood-Quaintance Kerryl E , Beyenal Haluk , Patel Robin 
Published: November 2023

Abstract

Background
Biofilms formed by antibiotic-resistant bacteria in wound beds present unique challenges in terms of treating wound infections. In this work, the in vivo anti-biofilm activity of a novel electrochemical bandage (e-bandage) designed to continuously deliver low amounts of hypochlorous acid (HOCl) was evaluated against wound biofilm infections caused by a clinical isolate of Pseudomonas aeruginosa resistant to all antibiotic classes except aminoglycosides.

Methods
5 mm skin wounds were created on the dorsal surface of Swiss-Webster mice and infected with 106 CFU of P. aeruginosa. Biofilms were allowed to form over 2 days, after which e-bandages with Tegaderm™ or Tegaderm only were placed on the wound beds. Specifically, mice were randomized to one of three experimental groups (n = 7-8): 1) Tegaderm only (control); 2) non-polarized e-bandage; 3) polarized e-bandage using a wearable potentiostat. After 48 hours, animals were sacrificed and 10 mm skin biopsies containing the wound and surrounding tissue were harvested for bacterial quantification. Histopathology was performed on H&E-stained sections of wound beds from each treatment group. Blood was screened with an inflammatory cytokine panel. Wound healing (% area reduction; digital measurement) and purulence (observational scoring) were assessed in pre- and post-treatment wounds.

Results
48 hours of polarized e-bandage treatment resulted in a mean reduction of 1.86 log10 biofilm CFUs/g (p &lt; 0.0001) vs non-polarized controls, and 2.18 log10 CFU/g reduction (p &lt; 0.0001) vs Tegaderm only controls (polarized, 7.6 ± 0.66 log10 CFU/g; non-polarized, 9.45 ± 0.26 log+10 CFU/g; Tegaderm only, 9.78 ± 0.16 log10 CFU/g). Compared to Tegaderm only, purulence reduction and wound healing were significantly higher for both non-polarized (purulence - p &lt; 0.0001; healing - p &lt; 0.01 ) and polarized treatment (purulence - p &lt; 0.0001; healing - p &lt; 0.0001) groups, but were not significantly different from each other. Histopathology and blood inflammation panel testing showed no significant differences between groups.

Conclusion
An HOCl-producing e-bandage reduced P. aeruginosa in wound biofilms, representing a potential antibiotic-free strategy for the treatment of recalcitrant wound infections.

Disclosures
Audrey N. Schuetz, MD, Merck: Advisor/Consultant Robin Patel, MD, Abbott Laboratories: Advisor/Consultant|Adaptive Phage Therapeutics: Grant/Research Support|Adaptive Phage Therapeutics: Mayo Clinic has a royalty-bearing know-how agreement and equity in Adaptive Phage Therapeutics.|BIOFIRE: Grant/Research Support|CARB-X: Advisor/Consultant|ContraFect: Grant/Research Support|Day Zero Diagnostics: Advisor/Consultant|HealthTrackRx: Advisor/Consultant|Mammoth Biosciences: Advisor/Consultant|Netflix: Advisor/Consultant|Oxford Nanopore Technologies: Advisor/Consultant|PhAST: Advisor/Consultant|See details: Patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic|See details: continued, patent on an anti-biofilm substance issued|TenNor Therapeutics Limited: Grant/Research Support|Torus Biosystems: Advisor/Consultant|Trellis Bioscience, Inc.: Advisor/Consultant