A Microneedle with Photoactive Electrospun Backing Layer Enables Multitherapy and Combined Drug Delivery to the Skin Wound

Abstract

Skin wound healing is frequently impaired by infection, inflammation, insufficient vascularization, and chronic pathological conditions, highlighting the need for therapeutic strategies that can address multiple barriers simultaneously. In this study, we developed a hybrid wound‐healing platform that integrates dissolvable microneedles (MNs) with a photoactive electrospun backing layer to enable sequential and complementary therapeutic functions. The electrospun scaffold (PGTBi), composed of poly(vinyl alcohol) and gelatin and loaded with taurine (Tau) and bismuth sulfide nanorods (Bi₂S₃ NRs), was fabricated to provide an extracellular matrix–mimicking dressing with optional near‐infrared (NIR)-responsive photothermal activity. The dissolvable MNs (PHA), composed of poly(methyl vinyl ether‐alt‐maleic acid) and hyaluronic acid and loaded with allantoin, were designed for rapid intratissue delivery following application to the wound bed. Upon insertion, the MNs dissolved within minutes, potentially enabling rapid exposure of allantoin within the wound tissue, while the electrospun PGTBi layer remained adhered to the wound surface, serving as a regenerative dressing and a secondary reservoir for bioactive components. The physicochemical properties, mechanical performance, dissolution behavior, photothermal response, antibacterial activity, and biocompatibility of the system were systematically evaluated in vitro. In vivo wound‐healing efficacy showed significantly enhanced wound closure, improved re‐epithelialization, and increased collagen deposition compared to control and non‐irradiated groups. Histological and biochemical analyses confirmed good biocompatibility and the absence of systemic toxicity. Overall, this study demonstrates the feasibility of a hybrid dissolvable MN-electrospun platform that provides rapid intratissue delivery combined with surface‐level reservoir of a therapeutic drug and optional photothermal activation, offering a promising approach for accelerated wound healing.