Polyphenol‐metal functionalized hydrogel dressing with sustained release, antibacterial, and antioxidant properties for the potential treatment of chronic wounds

Infection and chronic inflammation caused by oxidative stress are the main challenges in chronic wound healing. In this study, a silk fibroin/kappa-carrageenan (kCA)-based hydrogel functionalized with epigallocatechin-3-gallate (EGCG) and Cu2+ is fabricated for chronic wound healing. Polyphenol-metal functional complexes and ionic-covalent entanglement networks are prepared by introducing Cu2+. Cu2+ coordinates with kCA to enhance the mechanical properties and chelates with EGCG to form an EGCG-Cu2+ complex that continuously releases EGCG. The sustained release of EGCG enhances the antibacterial properties by synergizing with the effects of Cu2+. Furthermore, the prepared hydrogel exhibits a potent ability to scavenge excessive intracellular reactive oxygen species, controllable antioxidant bioactivity, and reliable biocompatibility. Ultimately, the resulting multifunctional hydrogel dressing provides a potential and effective strategy for chronic wound care management with increased mechanical strength and antibacterial and antioxidant properties.