Rod-Shaped Microgel Scaffolds with Interconnective Pores and Oxygen-generating Functions Promote Skin Wound Healing and Alleviate Hypertrophic Scar Formation

Abstract

The processes of skin wound healing and scar formation are complex, often involving hypoxia and inflammation, which create a pathological microenvironment that impedes normal healing. Improving wound oxygenation and reducing inflammation are crucial for accelerating healing and reducing scarring. Traditional dressings like sponges, gauze, and hydrogels struggle to balance moisture retention, breathability, and exudate absorption. To address these challenges, rod-shaped microgel scaffolds with larger surface areas and interconnected porous structures are explored to enhance gas transport, promoting wound oxygenation and moisture retention, thus accelerating healing and reducing scarring. Nanoparticles (NPs) are used to mediate the formation of microgels-assembled scaffold and to load catalase (CAT) for enhanced bioactivity. In vitro experiments showed that this material alleviated oxidative stress and reduced the activity of hypoxia-inducible factor-1α (HIF-1α), nuclear factor kappa B (NF-κB), and the downstream transforming growth factor-β1 (TGF-β)/Smad pathway in fibroblasts. The incorporation of CAT showed a significant promotion of M2-phenotype macrophage polarization. In vivo studies on rat and rabbit wounds demonstrated that the microgel scaffolds significantly improved exudate absorption and breathability, maintaining a moist and oxygenated environment. These scaffolds reduced tissue hypoxia, accelerated wound healing, and decreased hypertrophic scar formation in vivo. This innovative method leveraged the unique properties of microgels to effectively enhance skin tissue regeneration.