A Semi-Interpenetrating Network Hydrogel with Excellent Photothermal Antibacterial and ROS Scavenging Activities for MRSA-Infected Wounds

The prolonged infection of bacteria at the wound site may lead to serious physical problems. Herein, a multifunctional macroporous hydrogel with superior photothermal antibacterial and ROS scavenging activity (denoted as M-XG gel) was designed for the treatment of MRSA-infected wounds. The M-XG gels are composed of embedding Prussian blue nanoparticles (PBNPs) as photothermal converters and chelating ferric ions with xanthan gum (XG) and dopamine (DA) to form a semipermeable network. The introduction of DA occupies the cross-link sites of ferric ions, further increasing the pore size (200-500 μm open macropores) and endowing the hydrogel with ideal adhesion. The increase of cross-link sites in PBNPs formed a promising equilibrium M-XG gel with identical macroporous structures and toughened mechanical performance. The metal ligands between ferric ions and catechols, as well as the unique photothermal response of PBNPs, endow the hydrogels with a fast and stable near-infrared (NIR) photothermal conversion efficiency (48%). In the MRSA-infected SD rat trauma model, wounds treated with the M-XG gel group had completely closed after 14 days, effectively controlling wound bacterial infection and accelerating angiogenesis and collagen deposition, synergistically promoting infected wound healing. Therefore, the photothermal hydrogel with a semi-interpenetrating network demonstrates its great potential for infected wound tissue engineering.