Fig. 10. Glucose-responsive electricity auto-generating enzymatic-biofuel-cell (EBC) skin patch for wound healing. (a) Schematic of the EBC patch that consists of the glucose-responsive anodic enzyme glucose dehydrogenase (GDH) and cathodic counterpart bilirubin oxidase (BOD) mounted on a conductive carbon strip. Taking glucose as the substrate, electrons produced by the GDH anode flow along the carbon strip and further react with protons, which are then converted to water at the BOD cathode. (b) When the maximum current density is about 10 μA cm−2, the electrical potential generated by the EBC system is about 400 mV. (c) In the injured skin, an injury potential of about 25–45 mV was generated, which stimulated the opening of Piezo1, but with quick desensitization. When EBC was applied to induce an additional potential, a new potential distribution (∼0.5 V) was generated, thereby slowing Piezo1 desensitization and increasing the intracellular calcium uptake. (d) Summary of activation events during wound healing induced by a EBC skin patch; the external potential generated by the EBC patch induces membrane tension, activates Piezo1 channel opening and calcium influx, and stimulates the activity and migration of ECs and FBs, which ultimately promote wound healing by enhancing angiogenesis, collagen deposition and re-epithelialization of injured tissues. Reproduced from ref. 166 with the permission of Elsevier, copyright 2021.
