Quercetin Released Biomedical Hybrid Hydrogels Fabricated by Silk Fibroin and Sodium Alginate with Incorporation of Ag@rGO Nanosheets

The drug-encapsulated hybrid hydrogels possessed several expected properties, including porous microstructure, conductivity, adhesive strength, antioxidant activity, antibacterial properties, and cytocompatibility, and have great potential in biomedical applications, such as skin wound hydrogel dressings and bio-adhesives. In this paper, the quercetin-loaded hybrid hydrogels (SSA-QRs) were fabricated using silk fibroin (SF), alginate, and silver-doped reduced graphene oxide (Ag@rGO) nanosheets, incorporating quercetin-encapsulated PF-127 (PF127-QR) micelles. Scanning electron microscopy (SEM) images confirmed that the fabricated hybrid hydrogels possessed an interconnected porous microstructure. The mechanical properties of hydrogels could be regulated by adjusting the content of incorporated Ag@rGO nanosheets and PF127-QR micelles. Furthermore, the obtained SSA-QR hydrogels displayed the expected swelling properties, and the swelling rates could reach 1200-1700% in 120 min, in the equilibrium state. The fabricated SSA-QR hydrogels possessed apparent conductivity and self-healing ability. In addition, SSA-QR hydrogels exhibited strong adhesive performance on the surface of different materials, including skin, metal, wood, plastic, and glass. The typical antibacterial testing using Gram-positive <i>Staphylococcus aureus</i> (<i>S. aureus</i>) and Gram-negative <i>Escherichia coli</i> (<i>E. coli</i>) confirmed the excellent antibacterial activities of SSA-QR hydrogels. Moreover, SSA-QR hydrogels displayed good antioxidant ability and intracellular ROS scavenging ability. However, the increased content of Ag@rGO nanosheets could cause a great increase in the hemolysis ratio for SSA-QR hydrogels. Fluorescent images, cell counting kit-8 (CCK-8) assay, and cell scratch testing confirmed their excellent cytocompatibility and cell pro-migration ability. The available results demonstrated a facile strategy to prepare the quercetin-loaded hydrogel for applications of wound hydrogel dressing and bio-adhesives.