Bimetallic nanozymes with robust antibacterial effects for infected wound healing through diverse metal-precise regulation strategies

Abstract

The misuse of antibiotics exacerbates the problems of bacterial resistance, rendering antibiotic treatment ineffective and, in severe cases, posing life-threatening risks. Therefore, the development of novel antimicrobial materials and their clinical applications have garnered significant attention from healthcare professionals. Bimetallic nanozymes hold significant potential for treating clinical bacterial infections, owing to their superior antimicrobial activity and excellent biocompatibility. In this study, PdZn and PdCu bimetallic nanozymes with folded structures were synthesized using a one-step hydrothermal method. Their photothermal and peroxidase-like catalytic activities were compared, and the underlying causes of the variations in their catalytic performance were analyzed through computational studies. Additionally, the antimicrobial efficacy and wound-healing potential of these two nanozymes were evaluated. Experimental results demonstrated that PdCu exhibited superior catalytic performance compared to PdZn, which aligned with density functional theory calculations confirming its enhanced catalytic ability. In vitro antimicrobial experiments have successfully demonstrated that PdZn and PdCu can effectively inhibit the survival of Escherichia coli and Staphylococcus aureus down to less than 2 % by utilising the synergistic effect of photo-thermal catalysis at 980 nm near-infrared laser. Antibacterial experiments in vivo demonstrated that PdZn and PdCu nanozymes could promote wound healing and slow down the inflammatory response. PdCu exhibited a superior ability to promote wound healing compared with PdZn. PdCu + H₂O₂ + NIR and PdZn + H₂O₂ + NIR decreased the trauma area to 9.37 % and 6.04 % respectively, whereas the control group decreased it to only 41.21 %. Overall, this study further explores the potential of Pd-based nanozymes for biological applications and provides guidance for the synthesis of highly efficient Pd-based 2D nanobiomaterials.