Antibiofilm Activity of a Tunable Hypochlorous Acid‐Generating Electrochemical Bandage Controlled by a Wearable Potentiostat

Abstract

Chronic wound biofilm infections represent a major clinical challenge which results in a substantial burden to patients and healthcare systems. Treatment with topical antibiotics is oftentimes ineffective as a result of antibiotic‐resistant microorganisms and biofilm‐specific antibiotic tolerance. Use of biocides such as hypochlorous acid (HOCl) has gained increasing attention due to the lack of known resistance mechanisms. An HOCl‐generating electrochemical bandage (e‐bandage) is designed that delivers HOCl continuously at low concentrations targeting infected wound beds in a similar manner to adhesive antimicrobial wound dressings. A battery‐operated wearable potentiostat is developed that controls the e‐bandage electrodes at potentials suitable for HOCl generation. It is demonstrated that e‐bandage treatment is tunable by changing the applied potential. HOCl generation on electrode surfaces is verified using microelectrodes. The developed e‐bandage shows time‐dependent responses against in vitro Acinetobacter baumannii and Staphylococcus aureus biofilms, reducing viable cells to nondetectable levels within 6 and 12 h of treatment, respectively. The developed e‐bandage should be further evaluated as an alternative to topical antibiotics to treat wound biofilm infections.

HOCl-producing Electrochemical Bandages for TreatingPseudomonas aeruginosa-Infected Murine Wounds

“…Previously, we used microelectrodes to show that these e-bandages produce HOCl at the working electrode, and that the HOCl can penetrate into biofilms and explant tissue. 15, 20 Here, free chlorine spectrophotometer test kits (TNT866; Hach Company, Ames, IA) were used to measure total HOCl content in wounds. Wounds harvested from mice treated with polarized e-bandages had higher levels of HOCl than those treated with non-polarized e-bandages (p = 0.170) or Tegaderm alone (p = 0.0045) ( Table 1 ).…”

HOCl-producing Electrochemical Bandage is Active in Murine Polymicrobial Wound Infection

“…Previous results with e-bandages that produce an alternative reactive oxygen species, hydrogen peroxide (H2O2), found that wound healing was not only unimpeded but augmented, 20 however, antimicrobial efficacy of electrochemically generated H2O2 was less than HOCl against a broad spectrum of microorganisms. 12,22,[27][28][29][30] Therefore, a programmable e-bandage that can produce both HOCl and H2O2 for optimal biocide and wound healing augmentation respectively should be explored.…”

Evaluation of Treatment of Methicillin-ResistantStaphylococcus aureusBiofilms with Intermittent Electrochemically-Generated H2O2or HOCl

“…Biofilms (initial, control, and e-bandage treated) were quantified by calculating CFUs as described previously (24, 28, 29). Briefly, e-bandages were removed from TSA plates and placed in Petri dishes.…”

“…Previously, our group developed H 2 O 2 and (separately) HOCl-generating electrochemical bandages (e-bandages) consisting of carbon fabric working and counter electrodes (CEs) and a silver-silver chloride (Ag/AgCl) pseudo reference electrode to treat biofilms (24, 25). The electrodes were saturated with a phosphate buffered saline (PBS) based hydrogel and separated by layers of cotton fabric.…”