Enzyme-Responsive Polymeric Vesicles for Bacterial-Strain-Selective Delivery of Antimicrobial Agents

Abstract

Antimicrobial resistance poses serious public health concerns and antibiotic misuse/abuse further complicates the situation; thus, it remains a considerable challenge to optimize/improve the usage of currently available drugs. We report a general strategy to construct a bacterial strain-selective delivery system for antibiotics based on responsive polymeric vesicles. In response to enzymes including penicillin G amidase (PGA) and β-lactamase (Bla), which are closely associated with drug-resistant bacterial strains, antibiotic-loaded polymeric vesicles undergo self-immolative structural rearrangement and morphological transitions, leading to sustained release of antibiotics. Enhanced stability, reduced side effects, and bacterial strain-selective drug release were achieved. Considering that Bla is the main cause of bacterial resistance to β-lactam antibiotic drugs, as a further validation, we demonstrate methicillin-resistant S. aureus (MRSA)-triggered release of antibiotics from Bla-degradable polymeric vesicles, in vitro inhibition of MRSA growth, and enhanced wound healing in an in vivo murine model.

Keywords: antibiotic resistance; block copolymers; enzyme-responsive; polymeric vesicles; β-lactamase.