Bacterial Microenvironment-Responsive Polymeric Carriers for Antibacterial Agent Delivery

Bacterial infections challenge global health due to rising resistance and antibacterial agent inactivation. Encapsulating antibacterial agents into polymeric delivery systems enhances their stability, prolongs circulation, and reduces cytotoxicity. However, conventional polymeric carriers lack targeting and controlled release. In recent years, bacterial microenvironment-responsive polymers that react to pH, enzymes, or redox signals have enabled precise targeting and on-demand drug release. This review comprehensively summarizes recent advances in the application of bacterial microenvironment-responsive polymeric carriers for the delivery of antibacterial bioactive agents. Emphasis is placed on elucidating response mechanisms guided by bacterial microenvironmental characteristics, types of polymeric carriers, their applicable scenarios, and the delivery modalities. The review also highlights the advantages, challenges, and opportunities presented by various responsive platforms, offers insights into the material design principles and responsive schemes, and provides a theoretical foundation for the development of next-generation smart antibacterial agent delivery systems.