Multifunctional Prussian-Blue-Based Nanocomposite Hydrogel for Infected Wound Regeneration

The wound healing (WH) process is often severely hindered by bacterial infections and prolonged inflammatory responses. To address this problem, we developed a novel injectable nanocomposite DPB-ODQ hydrogel, which comprises polydopamine-modified Prussian blue nanoparticles (PB@PDA, also called DPB) and an oxidized dextran/quaternized chitosan (QCS)-based Schiff-base network. This hydrogel possesses a highly interconnected porous structure, an excellent swelling rate (730%), rapid gelling speed (45 s), a high mass retention rate over a three-day period (73.20%), and exceptional self-healing properties. Based on the presence of PDA and the Schiff base, it also exhibited good adhesive strength (13.5 kPa). In addition, under near-infrared irradiation at 1.0 W/cm², temperatures increased by more than 35 °C within 5 min, indicating excellent photothermal (PT) performance. The PT performance of DPB, synergized with the inherent antibacterial properties of QCS, endowed it with a bactericidal rate exceeding 96% against both <i>Staphylococcus aureus</i> and <i>Escherichia coli</i>. In vitro cell experiments have shown that it significantly promoted fibroblast proliferation and migration. In experiments involving mice infected with <i>S. aureus</i>, DPB-ODQ demonstrated an impressive WH rate of 92.82%, greatly promoting collagen deposition.