Dynamic Metal-Phenolic Coordinated Hydrogel for Synergistic Photothermal/Chemodynamic Therapy against Biofilm-Infected Wounds and Real-Time Monitoring

The development of multifunctional hydrogel dressings integrating injectability, self-healing capability, tissue adhesion, multimodal antibacterial mechanisms, and real-time wound status monitoring remains a critical challenge for combating bacterial biofilms and accelerating wound healing. Herein, we present a dynamically cross-linked nanocomposite hydrogel (QCS-TA/LDH-panis) via Fe³⁺/Mn²⁺-mediated coordination between tannic acid (TA)-modified quaternized chitosan (QCS-TA) and polysulfonatoaniline-intercalated FeMn-layered double hydroxide (LDH-panis). The LDH-panis nanohybrids, synthesized through in situ polymerization of 3-sulfonatoaniline within FeMn-LDH interlayers, exhibit a near-infrared (NIR)-responsive photothermal effect (η = 64.3%) and pH/H₂O₂-activated peroxidase-like activity for biofilm-disrupting hydroxyl radical (^•OH) generation. Concurrently, the QCS-TA matrix enables a "capture-and-kill" mechanism via electrostatic interactions (quaternary ammonium groups) and bacterial affinity adhesion (catechol/pyrogallol moieties). Under near-infrared (NIR) irradiation, synergistic mild photothermal/chemodynamic therapy (mPTT/CDT) combined with contact-killing achieved >95% eradication of Staphylococcus aureus and Escherichia coli biofilms. Notably, the hydrogel's conductivity enabled real-time monitoring of wound exudate and temperature fluctuation during the healing progression. In vivo evaluations confirmed accelerated infected wound regeneration (98.2% closure in 12 days) through biofilm elimination, inflammatory suppression, reepithelialization, and collagen deposition. This multifunctional hydrogel unifies dynamic adaptability, multimodal antibacterial therapy, and sensing intelligence, offering a promising strategy for the clinical management of biofilm-associated infection.