Collagen Scaffolds Functionalized by Cu-Chelated EGCG Nanoparticles with Anti-Inflammatory, Anti-Oxidation, Vascularization, and Anti-Bacterial Activities for Accelerating Wound Healing.

Skin injury is a common health problem worldwide, and the highly complex healing process poses critical challenges for its management. Therefore, wound dressings with salutary effects are urgently needed for wound care. However, traditional wound dressing with a single function often fails to meet the needs of wound repair, and the integration of multiple functions has been required for wound repair. Herein, Cu-chelated epigallocatechin gallate nanoparticles (EAC NPs), with radical scavenging, inflammation relieving, bacteria restraining, and vascularization accelerating capacities, are adopted to functionalize collagen scaffold, aiming to promote wound healing. Radical scavenging experiments verify that EAC NPs could efficiently scavenge radicals. Additionally, EAC NPs could effectively remove Escherichia coli and Staphylococcus aureus. HO stimuli-responsive EAC NPs show slow and sustained release properties of Cu. Furthermore, EAC NPs exhibit protective effects against HO-induced oxidative-stress damage and anti-inflammatory activity in vivo. Physicochemical characterizations show that the introduction of EAC NPs does not disrupt the gelation behavior of collagen, and the composite scaffolds (CS) remain porous structure similar to collagen scaffold. Animal experiments demonstrate that CS could promote wound healing through improving the thickness of renascent epidermis and number of new vessels. CS with multiple salutary functions is a promising dressing for wound care.