Bio-Based Silk Fibroin Composites with Enhanced Antioxidant Activity for Accelerated Wound Healing

Free radicals, generated in the living system through diverse biochemical pathways, can damage biomolecules, thereby causing oxidative stress, impairing tissue function, and delaying wound healing. This has stimulated increasing interest in antioxidant-based strategies to neutralize free radicals and protect biological structures. Gallic acid (GA), a plant-derived polyphenol, is well-known for its potent free-radical scavenging activity. However, its poor solubility and instability under physiological conditions limit its practical applications. In this work, GA was coordinated with ferric ions to form ultrasmall Fe-GA nanoscale coordination polymers (Fe-GA NCPs), designed to enhance its stability and maintain antioxidant activity. To provide a biocompatible and mechanically stable carrier, silk fibroin (SF) from silkworm cocoons, an FDA-approved biomaterial widely used in medical applications, was selected as the carrier. The resulting RSF/Fe-GA NCPs exhibited strong hydroxyl and DPPH radical scavenging abilities, improved mechanical strength and flexibility, and excellent biocompatibility. In vivo studies confirmed accelerated wound closure, enhanced tissue regeneration, and reduced inflammatory marker expression, demonstrating the potential of these antioxidant fibers as multifunctional materials for wound healing and other bio-based applications.