Antimicrobial hydrogel microneedle loading verteporfin promotes skin regeneration by blocking mechanotransduction signaling

Excessive scar formation has severe physiological and psychological effects on patients, and tissue restoration to functioning without scar generation after wounding continues to be a significant challenge. Yes-associated protein (YAP) is a downstream effector of the Hippo pathway that interacts with the transcriptional-enhanced associate domain to regulate stem cell proliferation, tissue growth, and organ size. Blocking mechanotransduction signaling can reduce tissue fibrosis and scar formation. This study developed a biocompatible detachable hydrogel microneedle (MN) system for scarless wound healing. The photosensitizing drug bismuth nanosheets (Bi) and YAP signaling pathway inhibitor verteporfin (Vp) were integrated into the pyramidal MN array. The MN system has sufficient mechanical strength to penetrate the skin, after the separable connection degrades, the tips can be left inside the tissue for continuous active release, and the substrate can be removed safely. The study shows that inhibition of YAP signaling encouraged scar-free wound healing without fibrosis and with the regeneration of secondary skin elements (hair follicles, sebaceous glands). Therefore, MN can serve as an excellent drug delivery system and will have numerous practical benefits in scar-free wound regeneration.