Engineering Bacteriophage Cocktail with Mutually Promoted Chemodynamic–Photodynamic Activity for Targeted and Synergistic Biofilm Eradication

Biofilms formed by bacterial symbiosis significantly strengthen bacterial resistance to external interference and cause chronic infections. Herein, a chemodynamic therapy (CDT) and photodynamic therapy (PDT) coarmed bacteriophage cocktail was developed to eradicate <i>Staphylococcus aureus</i> biofilms by conjugating aggregation-induced emission photosensitizer (AIE PSs), glucose oxidase (GO_<i>x</i>), and horseradish peroxidase (HRP) on the bacteriophage surface. Leveraging the particular specificity of the bacteriophage toward host bacteria, the three conjugates can penetrate the biofilm and colocalize on the inner bacterial surface. When thus enriched, AIE PSs exhibited intensified fluorescence, enabling labeling and killing pathogens via photoirradiation-generated singlet oxygen. After combining AIE PSs with GO_<i>x</i>/HRP, which can convert glucose nutrients into H₂O₂ and ultimately to hydroxyl radicals via cascade catalysis, the bactericidal efficiency was dramatically improved compared to individual phage-CDT (>468%) or phage-PDT (>290%) at the same PFU concentration of phage. The colocalized PSs and enzymes on the confined space of the bacterial surface are mutually promoted in the microenvironment of the biofilm, realizing synergistic enhancement. This strengthened bacteriophage cocktail offers an effective strategy for treating biofilm-related clinical superbug infections.