Multifunctional Microneedle Patch with Antibacterial, Antioxidant, and Pro-Regenerative Properties for Scarless Wound Healing.

Trauma can easily cause large-area skin tissue defects and is accompanied by bacterial infection, excessive oxidative stress, and unregulated inflammation, resulting in delayed healing and scar formation. This study presents a microneedle patch with a core-shell architecture, designed to address these challenges through integrated therapeutic functionalities. The shell of the microneedles incorporates melanin nanoparticles chelated with copper ions for controlling bacterial infection, and the core of the microneedles is filled with salvianolic acid B microparticles to reduce scar formation. In vitro analyses demonstrated the patch's capacity to effectively eliminate reactive oxygen species (ROS), inhibit bacterial growth, and promote fibroblast migration and angiogenesis. Computational simulations further revealed its controlled drug diffusion, ensuring sustained therapeutic effects. In vivo experiments using S. aureus-infected wound models confirmed the patch's efficacy in accelerating wound closure, reducing inflammation, and mitigating scar formation. Histopathological analysis and RNA sequencing highlighted its role in modulating inflammatory and collagen deposition pathways, while promoting balanced tissue regeneration. The microneedle system offers a promising platform for wound healing and scar prevention, combining targeted drug delivery with multifunctional therapeutic effects.