Kies, Paige J.

ABSTRACT Biofilms hinder wound infection healing, making wound infections a healthcare challenge for which innovative treatments are needed. A 1.77 cm 2 electrochemical bandage (e-bandage), which generates the biocide hypochlorous acid (HOCl), has shown promising anti-biofilm activity in vitro , ex vivo , and in vivo . The e-bandage is a three-electrode system operationalized by a hydrogel. In addition to providing a conductive electrolyte for the electrodes, the hydrogel provides a protective barrier for the wound. How different hydrogels impact e-bandage functionality is not completely defined. Here, the in vitro activity of seven clinically available hydrogels (xanthan gum, 3M, Duoderm, Prontosan, Purilon, Skintegrity, and Solosite) was evaluated with 1.77 cm 2 HOCl-generating e-bandages using a potentiostat with a multiplexer in a membrane biofilm model against methicillin-resistant Staphylococcus aureus IDRL-6169 and Acinetobacter baumannii ATCC-17978. When applied with polarized HOCl-producing e-bandages, all evaluated hydrogels except Solosite yielded ≥5.5 log 10 CFU/cm 2 reductions in bacterial quantities after 6 h of treatment, with most being below the detection limit at that time point. Prontosan exhibited antibacterial activity independent of e-bandage. Results of this study inform the selection of clinically available hydrogels that may be suitable for use with a 1.77 cm 2 HOCl-producing e-bandage. IMPORTANCE In this study, it was shown that some clinically available hydrogels, combined with a 1.77 cm 2 HOCl-generating electrochemical bandage, deliver time-dependent antimicrobial activity against methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii biofilms, offering a potential approach to treat wound infections, including those caused by antimicrobial-resistant bacteria.

ABSTRACT An electrochemical bandage (e‐bandage) that generates hydrogen peroxide (H 2 O 2 ) through a combination of working, counter and reference electrodes used with an electrolyte‐providing hydrogel is being developed for wound infection management. e‐Bandage biocidal activity was previously demonstrated using Xanthan gum hydrogel. For clinical use, clinically used hydrogels would be ideal, but their use with the described e‐bandage has not been shown. The goal of this work was to evaluate the biocidal activity of off‐the‐shelf, clinically used hydrogels when used with a 1.77 cm 2 H 2 O 2 ‐producing e‐bandage. e‐Bandage electrochemical parameters and activity against methicillin‐resistant Staphylococcus aureus IDRL‐6169 and Acinetobacter baumannii ATCC‐17978 biofilms were assessed with six off‐the‐shelf hydrogels. Variations in hydrogel composition affected electrochemical parameters, which was associated with differences in biocidal activity. Results of this study inform the selection of off‐the‐shelf hydrogels for use with H 2 O 2 ‐producing e‐bandages.

Abstract Background Wound biofilm infections impact ∼2% of the United States and at-risk individuals often have underlying morbidities such as diabetes. Antibiotics and topical approaches like debridement or silver dressings have had limited success, underscoring a need for strategies that efficiently target pathogens in wound beds. Methods We developed a hydrogen peroxide (H2O2) generating electrochemical bandage (e-bandage) composed of carbon fabric electrodes separated by cotton fabric with an Ag/AgCl reference electrode (RE) placed between cotton fabric layers. The e-bandage is controlled by a wearable micropotentiostat (MP); H2O2 is generated by O2 + 2H++ 2e- → H2O2. O2 is dissolved on a primary working electrode with negative polarity compared to the RE while a positively polarized secondary counter electrode generates H+ and e-. The H2O2 e-bandage/MP device has in vitro activity against mono- and dual-species bacterial and fungal biofilms. We showed that the H2O2 e-bandage decreased the burden of methicillin-resistant Staphylococcus aureus and/or Pseudomonas aeruginosa with difficult-to-treat resistance in a murine wound infection model. Given this, we initiated a H2O2 e-bandage safety assessment on healthy human skin. Here, testing of a non-polarized, circular (2 cm diameter) device pre-loaded with biocompatible hydrogel containing 0.9% NaCl is reported. Sterilized e-bandages assessed in a shelf-life study retained activity for two weeks. Adults with intact forearm skin were then recruited to the Clinical Research Trials Unit at the Mayo Clinic. Consented individuals had a non-polarized e-bandage covered by Tegaderm placed on their forearm. A MP enclosed in a biocompatible case was connected to the e-bandage and secured using skin tape. One day later, the device was removed and a follow-up phone call made six days later to assess for adverse effects. Results Three volunteers wearing a non-polarized H2O2 e-bandage experienced no discomfort, irritation, allergic reaction, or skin discoloration after device removal and seven days post device placement. Conclusion These preliminary studies combined with the previously performed murine bacterial biofilms work support further studies of this novel device for treating wound infections caused by antimicrobial resistant pathogens. Disclosures Robin Patel, MD, a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, a: See above|MicuRx Pharmaceuticals and BIOFIRE: Grant/Research Support|PhAST, Day Zero Diagnostics, Abbott Laboratories, Sysmex, DEEPULL DIAGNOSTICS, S.L., Netflix, Oxford Nanopore Technologies and CARB-X: Advisor/Consultant|Up-to-Date and the Infectious Diseases Board Review Course.: Honoraria