Pagoda-Inspired Microneedles for Multiphase Coverage Wound Healing

Microneedle patches are considered as an attractive technology for wound treatment. Current researches are devoted to enhancing the structure and functionality of microneedles to cover multiphase for wound healing. Here, we present a desired quaternized chitosan-coated pagoda-inspired microneedle (QPDMN) patch loaded with diverse drugs to treat wounds. The QPDMN tips are comprised of a bottom layer loading vascular endothelial growth factor (VEGF) and a top layer containing antimicrobial peptides (AMPs), as well as with the outer surface coated with quaternized chitosan (QCS). When applied, QCS could firstly contact wounds and rapidly promote blood clotting. Subsequently, AMPs released from top needles could remarkably inhibit bacterium growth, while VEGF released from bottom tips effectively facilitate tissue regeneration. Animal experiments have further proved that the QPDMN system has rapid hemostasis, enhanced angiogenesis, anti-inflammation and collagen deposition performances, coordinating the different phases of wound healing. Thus, we believe that the pagoda-like microneedles could be an excellent multiphase-coverage therapeutic agent in clinic wound healing.