Microenvironment‐Activated Nanozyme‐Armed Bacteriophages Efficiently Combat Bacterial Infection

Abstract

AbstractBacterial infection is one of the greatest challenges to public health, requiring new therapeutic methods. Herein, an innovative nanozyme‐armed phage (phage@palladium (Pd)) system is fabricated for combating bacterial infection. The proposed phage@Pd preserves the function of the phages to achieve precise recognition and adhesion to the host Escherichia coli. In aid of the phages, the ultrasmall Pd nanozymes equipped with conspicuous pH‐dependent peroxidase‐like activity can generate toxic hydroxyl radical around the bacteria in acidic and hydrogen‐peroxide‐overexpressed infection microenvironment while remaining inert in physiological conditions, thus realizing the noteworthy elimination of bacteria at infected sites, and in the meantime ensuring the biological safety of phage@Pd in healthy tissues. In addition, the filamentous structure of phage@Pd can also enhance its bactericidal efficiency toward nonhost bacteria by randomly entangling on them, indicating possible broad‐spectrum germicidal efficacy. Notably, phage@Pd can not only eradicate planktonic bacteria, but also kill the bacteria inside the biofilm in vitro. For both in vivo models of acute bacterial pneumonia or subcutaneous abscess, phage@Pd shows significant activity in eliminating infection and promoting tissue recovery. These results demonstrate that the phage@Pd nanohybrid is a safe and effective antimicrobial agent, providing a new insight into development of advanced antibacterial materials.