Mussel-inspired multifunctional gelatin microgel for accelerating full-thickness wound healing

The complete wound healing is challenging in clinical practice originating from bleeding, inflammation or infection, leading to poor healing process. Here, inspired by the mussel's adhesion, we successfully developed a polydopamine functionalized gelatin microgel (PGM) using a simple emulsification-chemical crosslinking technique, which method enables the controllable and facile generation of PGM, allowing for the facile production of PGM with different sizes (15-100 microm). PGM demonstrates remarkable adaptability to complex wound shapes and depths, ensuring stable tissue adhesion even in dynamic and moist microenvironment, the optimal adhesive strengths of PGM adhering to porcine skin is 10.3 kPa. Particularly, its multifunctional performance integrates cell migration, hemostatic activity, and reactive oxygen species scavenging. In addition, skin wound healing in a full-thickness skin defect model was achieved by down regulating TNF-a expression while promoting collagen regeneration and CD31 expression. Altogether, a new strategy of injectable microgel is developed for drug-free, efficient full-thickness wound healing, offering significant potential for clinical applications.