A pH-Mediated Electronic Wound Dressing for Controlled Drug Delivery

Abstract

Topical administration of drugs in a timely manner according to the physiological need at the wound site can enhance the healing rate of chronic wounds. Herein, an electronic wound dressing that enables active topical drug delivery in response to electrically induced pH change is demonstrated for potential treatment of chronic wounds. In this platform, the pH of the dressing is controlled using an electrical field. This allows precise electrical control over the temporal profile of pH-mediated drug release. This engineered dressing is comprised of microfabricated electrodes serving as anode and cathode, a pH sensitive hydrogel, and controlled electronic circuitry. The anode is coated with a pH sensitive poly(ethylene glycol)-diacrylate/Laponite hydrogel layer containing drug loaded chitosan nanoparticles (ChPs). Applying a DC voltage between the electrodes results in a local change in pH near the electrodes. In basic environments found near the anode, the ChPs release their drug due to the dehydration process, while in acidic environments the release profile is negligible. Turning off the DC voltage results in immediate pH recovery and cessation of drug release. The biocompatibility of the dressing has also been confirmed-the pH shift resulting from application of DC voltage does not affect the wound pH significantly.

Keywords: chitosan nanoparticles; flexible wound dressings; stimuli-responsive drug delivery.