CCDesign and research of synergistic antibacterial composite materials based on MOF-stabilized enzymes and in situ grown AgNPs

Overusing antibiotics has accelerated the rapid emergence and spread of resistant strains, posing a serious threat to global public health. To address this challenge, this study developed a synergistic antibacterial composite material, CAT@ZIF-8/AgNPs, based on the metal-organic framework material ZIF-8, catalase (CAT), and silver nanoparticles (AgNPs). First, CAT was encapsulated in ZIF-8, effectively enhancing the enzyme's stability and catalytic activity in complex environments. AgNPs were then grown in situ on the surface of CAT@ZIF-8, which endowed the composite material with broad-spectrum antibacterial properties and synergistically enhanced the antibacterial effect through silver ion release and enzymatic catalysis. Enzyme activity tests demonstrated that CAT@ZIF-8 exhibited excellent stability, retaining over 50 % activity at pH 11, above 80 % at 50 °C, and over 70 % in organic solvents, significantly outperforming free CAT under all tested conditions. Antibacterial tests indicated that the composite material exhibited significant synergistic antibacterial effects against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Furthermore, cytotoxicity tests revealed that the composite material demonstrated good biocompatibility with human keratinocytes (HaCaT) at concentrations up to 500 μg/mL. The CAT@ZIF-8/AgNPs composite material showcases efficient antibacterial performance and good biosafety through the synergistic action of enzymes and silver nanoparticles, indicating broad application prospects.