Improved pharmacodynamics of epidermal growth factor via microneedles-based self-powered transcutaneous electrical stimulation.

Epidermal growth factor is an excellent drug for promoting wound healing; however, its conventional administration strategies are associated with pharmacodynamic challenges, such as low transdermal permeability, reduction, and receptor desensitization. Here, we develop a microneedle-based self-powered transcutaneous electrical stimulation system (mn-STESS) by integrating a sliding free-standing triboelectric nanogenerator with a microneedle patch to achieve improved epidermal growth factor pharmacodynamics. We show that the mn-STESS facilitates drug penetration and utilization by using microneedles to pierce the stratum corneum. More importantly, we find that it converts the mechanical energy of finger sliding into electricity and mediates transcutaneous electrical stimulation through microneedles. We demonstrate that the electrical stimulation applied by mn-STESS acts as an "adjuvant" that suppresses the reduction of epidermal growth factor by glutathione and upregulates its receptor expression in keratinocyte cells, successfully compensating for receptor desensitization. Collectively, this work highlights the promise of self-powered electrical adjuvants in improving drug pharmacodynamics, creating combinatorial therapeutic strategies for traditional drugs.

Accelerated Skin Wound Healing by Electrical Stimulation.

When the integrity of the skin got damaged, an endogenous electric field will be generated in the wound and a series of physiological reactions will be initiated to close the wound. The existence of the endogenous electric field of the wound has a promoting effect on all stages of wound healing. For wounds that cannot heal on their own, the exogenous electric field can assist the treatment. In this review, the effects of exogenous electrical stimulation on wound healing, such as the inflammation phase, blood flow, cell proliferation and migration, and the wound scarring is overviewed. This article also reviews the new electrical stimulation methods that have emerged in recent years, such as small power supplies, nanogenerators (NGs), and other physical, chemical or biological strategies. These new electrical stimulation methods and devices are safe, low-cost, stable, and small in size. The challenge and perspective are discussed for the future trends of the electrical stimulation treatment in accelerating skin wound healing.