Local Delivery of Glabridin by Biomolecular Microneedle to Accelerate Infected Wound Healing.

Applying antibacterial polymers and pro-regenerative small molecules are two individual strategies for accelerating wound healing. However, integrating those two unique approaches into one therapeutic platform that meets clinical requirements is still a challenge. Herein, a series of antibacterial gelatin methacrylate (GelMA)/ε-polylysine (ε-PL) composite hydrogels (termed as GP-n HGs, n = 0, 10, 20, and 30, respectively) are innovatively fabricated by ultraviolet light (UV) crosslinking. The GP-n HGs are proved to be broad-spectrum antibacterial and biocompatible. Among those GP-n HGs, the GP-20 HG is selectively processed into microneedle following a mold-casting method. Then, the glabridin is loaded into those needles to produce composite microneedle termed GP-20@Gla MN. An S. aureus-infected full-thickness defect model in rats is created to evaluate the wound-healing effect of GP-20@Gla MN. Furthermore, an RNA sequencing assay is performed to explore the possible molecular mechanisms of glabridin in promoting tissue regeneration, and many positive routes are summarized. This work is of significant novelty in fulfilling complex clinical needs by simultaneously optimizing the advanced microneedles' chemical compositions and physical structures. This work will provide a promising therapeutic platform for treating infected and chronic wounds.