Engineered phage-silver nanoparticle complexes as a new tool for targeted therapies.

The emergence of antibiotic-resistant bacteria underscores the need for innovative and precise therapeutic strategies. Here, we present a novel approach to combating bacterial infections by developing engineered phage-silver nanoparticle (AgNP) complexes as targeted therapeutic agents. We first synthesized and characterized AgNPs using advanced techniques, ensuring precise particle size and surface charge control. Subsequently, we combined the AgNPs with engineered M13 bacteriophages (Li5 phage) displaying a foreign peptide that provides selectivity for specific E. coli strains. We found that the AgNP@Li5 phage molecular complex exhibited highly selective antibacterial activity against E. coli F+, F- and pathogenic O157:H7 strains while having little impact on other bacterial species (p < 0.0001). AgNPs@Li5 demonstrated antibacterial activity with similar MIC values for E. coli TG1 and E. coli F-, inhibiting bacterial growth at a 1:16 dilution. In contrast, the antibacterial activity against E. coli O157:H7 was lower, with a dilution value of 1:8, compared to the other E. coli strains. The specificity of this approach minimizes collateral damage to surrounding bacteria, addressing a key challenge in conventional antimicrobial therapies. This system can be easily customized to target pathogens and tumors by simply modifying the peptides displayed on the phages. Our findings highlight the potential for innovative approaches in targeted therapy.