Bio‐Responsive Hydrogel for Targeted on‐Demand Release of a Phage Cocktail for Treatment of Pseudomonas aeruginosa Infection

Abstract Antimicrobial resistance (AMR) is a critical global health issue, driving the need for novel therapeutic strategies such as bacteriophage (phage) therapy, which offers a comparatively targeted approach to bacterial infections. However, phage therapy faces substantial hurdles, including phage resistance, delivery challenges, insufficient residence time, and reduced antibacterial efficacy with time. This study presents the development of a gelatin‐based hydrogel system designed to deliver a phage cocktail targeting antibiotic‐resistant Pseudomonas aeruginosa and its biofilms. The hydrogel is responsive to P. aeruginosa secreted enzymes, specifically gelatinases, which trigger its degradation and enable the “on‐demand” release of phages for targeted antibacterial action and a prolonged effect. The simultaneous administration of a phage cocktail, FJK.R9‐30 and MK.R3‐15, within this hydrogel effectively addresses the phage resistance challenge. The phage‐hydrogel not only completely inhibits biofilm formation but also disrupts established biofilms. Validation in an ex vivo human skin infection model confirms the hydrogel's specificity in responding to P. aeruginosa and its strong antibiofilm properties. Additionally, the system demonstrates cytocompatibility, showing no cytotoxic effects on human dermal fibroblasts. This multi‐phage hydrogel approach effectively tackles phage resistance and enhances phage localization at infection sites, offering a promising solution for advancing phage therapy in combating the AMR crisis.