Chemically Grafted Nanozyme Composite Cryogels to Enhance Antibacterial and Biocompatible Performance for Bioliquid Regulation and Adaptive Bacteria Trapping

Excessive biofluid and infection around wounds hinder wound healing. However, conventionally antibacterial wound dressings cannot simultaneously achieve effective biofluid control and intelligent infection treatment, tending to overhydrate wounds and develop drug-resistant bacteria due to the limitations of antibacterial components and material structures. The design of a nanozyme composite cryogel with interconnected macroporous structures, excellent designability, and lower chance of drug-resistance is greatly needed. Herein, Fe-MIL-88NH2 nanozyme is grafted to glycidyl methacrylate functionalized dialdehyde chitosan via Schiff base reaction, and acryloyl Pluronic 127 (PF127-DA) is used as a cross-linking agent to fabricate nanozyme composite cryogels (CSG-MX) as a wound dressing to enhance antibacterial and biocompatible performance for biofluid management and wound infection therapy. CSG-MX has great hydrophilicity, acid-enhanced positive charge, pH-responsive release, rebinding of nanozymes, and excellent peroxidase and oxidase mimicry activity (generation of •OH and O2•- radicals). Notably, due to the negative potential of bacteria, the impact of infection on pH value, and the enzyme-like activity as well as the reversible release of nanozymes influenced by pH, CSG-MX can achieve intelligently adaptive trapping and killing of bacteria. CSG-MX has enormous potential to be a next-generation wound dressing for biofluid management and bacterial infection treatment in the clinic.