Dextran based dual-dynamic-network hydrogel for chronic wound healing with mechanically adaptive, antibacterial, and...

Chronic non-healing wounds requires dressings that combine flexibility, infection control, and responsive environments, a need unmet by current options. In this study, we developed a dual-dynamic-network hydrogel using covalent Schiff base bonds and non-covalent Al³⁺-carboxyl coordination with oxidized dextran (ODex), polyethyleneimine-modified gelatin (PEI-Gel), polyacrylic acid (PAA), and aluminum ions (Al³⁺), achieving three synergistic functions critical for clinical application. The DPA (ODex/PEI-Gel/PAA) hydrogel exhibits tissue-like deformability, with an elongation capacity of 920.9 ± 1.2 % and a tensile strength of 0.54 ± 0.3 MPa, while preserving structural integrity under cyclic stress conditions. In vitro tests demonstrated the hydrogel's antibacterial efficacy, with MIC₉₀ values of 25, 20, and 6 mg/mL against Escherichia coli, Staphylococcus epidermidis, and S. saprophyticus, respectively. The hydrogel's pH-responsive drug release mechanism facilitates intelligent therapeutic delivery, achieving over 90 % cumulative release of emodin at pH 3.0 within 168 h. Overall, this work highlights the promising potential of the antibacterial hydrogel drug delivery platform with superior mechanical characteristics for the treatment of chronic cutaneous wounds.