Green Antibacterial-Antioxidant Hydrogel for Infected Wound Healing: Tea Polyphenol and Biosynthesized Silver Nanoparticles in a Deacetylated Sphingan WL Matrix

Effective management of infected wounds requires biomaterials that simultaneously combat infection, oxidative stress, and impaired healing. This study developed a green-synthesized multifunctional hydrogel (TP-Ag@BDH) by incorporating tea polyphenol (TP) and TP-capped silver nanoparticles (TP-AgNPs) into a BDDE-cross-linked matrix of deacetylated sphingan WL gum (DWL). This design integrates a pH-responsive DWL scaffold, multifunctional TP (contributing hemostatic and antioxidant activities), and antibacterial TP-AgNPs. The resulting composite exhibited essential wound-management properties, including suitable mechanical strength ( G ′ ≈ 2000 Pa), inherent self-healing capability, reliable tissue adhesion, and pH-responsive swelling behavior governed by the DWL matrix(i) a pH-responsive and biocompatible. Release studies revealed pH-dependent release for both TP and silver, albeit with contrasting patterns: TP release was faster under both acidic and alkaline conditions (with the highest release at pH 5.5), whereas silver release was highest at pH 9.5. Both components displayed biphasic profiles (initial burst followed by sustained release). The hydrogel demonstrated excellent biocompatibility (cell viability >80%), potent radical scavenging (94.0% DPPH clearance), and broad-spectrum antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa . In a rat tail amputation model, it reduced blood loss to 35.0 ± 2.0 mg. In an S. aureus -infected wound model, it accelerated wound closure (78.2% at day 7; 95.3% at day 14) and promoted high-quality tissue repair with enhanced collagen deposition and minimal scarring. This study successfully developed a green-synthesized, multifunctional polysaccharide-based hydrogel. Its pH-responsive properties, controlled release characteristics, and integrated therapeutic strategy offer a promising platform for the effective management of infected wounds.