Silver is a commonly used topical antimicrobial. However, technologies to immobilize silver at the wound surface are lacking, while currently available silver-containing wound dressings release excess silver that can be cytotoxic and impair wound healing. We have shown that precise concentrations of silver at lower levels can be immobilized into a wound bed using a polyelectrolyte multilayer attachment technology. These silver nanoparticle-impregnated polyelectrolyte multilayers are noncytotoxic yet bactericidal in vitro, but their effect on wound healing in vivo was previously unknown. The purpose of this study was to determine the effect on wound healing of integrating silver nanoparticle/polyelectrolyte multilayers into the wound bed. A full-thickness, splinted, excisional murine wound healing model was employed in both phenotypically normal mice and spontaneously diabetic mice (healing impaired model). Gross image measurements showed an initial small lag in healing in the silver-treated wounds in diabetic mice, but no difference in time to complete wound closure in either normal or diabetic mice. Histological analysis showed modest differences between silver-treated and control groups on day 9, but no difference between groups at the time of wound closure. We conclude that silver nanoparticle/polyelectrolyte multilayers can be safely integrated into the wound beds of both normal and diabetic mice without delaying wound closure, and with transient histological effects. The results of this study suggest the feasibility of this technology for use as a platform to affect nanoscale wound engineering approaches to microbial prophylaxis or to augment wound healing.
From the *Department of Surgical Sciences, School of Veterinary Medicine, †Department of Chemical and Biological Engineering, and ‡Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison; §Department of Ophthalmology and Vision Science, University of California, Davis School of Medicine; ‖Department of Surgical and Radiological Sciences, University of California, Davis, School of Veterinary Medicine; ¶Cummings School of Veterinary Medicine, Tufts University, Medford, Massachusetts; and #Department of Surgery, School of Medicine, University of Colorado, Denver.
Authors Agarwal, Abbott, Murphy, Schurr, and McAnulty are founding members of Imbed Biosciences, Inc. Author Agarwal acknowledges support from a fellowship from the Ewing Marion Kauffman Foundation. The studies described here were funded in their entirety by an RC-2 grant from the National Institutes of Health.
Address correspondence to Jonathan F. McAnulty, DVM, PhD, University of Wisconsin, School of Veterinary Medicine, Department of Surgical Sciences, 2015 Linden Drive, Madison, WI 53706.
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