Programmable antibiotic delivery to combat methicillin-resistant Staphylococcus aureus through precision therapy.

The rapid dissemination of life-threatening multidrug-resistant bacterial pathogens calls for the development of new antibacterial agents and alternative strategies. The virulence factor secreted by bacteria plays a crucial role in the sophisticated processes during infections. Inspired by the unique capacity of many bacteria inducing clotting of plasma to initiate colonization, we propose a programmable antibiotic delivery system for precision therapy using methicillin-resistant S. aureus (MRSA) as a model. Coagulase utilized by MRSA to directly cleave fibrinogen into fibrin, is an ideal target not only for tracking bacterial status but for triggering the collapse of fibrinogen functionalized porous microspheres. Subsequently, staphylokinase, another virulence factor of MRSA, catalyzed hydrolysis of fibrin to further release the encapsulated antibiotics from microspheres. Our sequential triggered-release system exhibits high selectivity to distinguish live or dead MRSA from other pathogenic bacteria. Furthermore, such programmable microspheres clear 99% MRSA in 4 h, and show increased efficiency in a wound healing model in rats. Our study provides a programmable drug delivery system to precisely target bacterial pathogens using their intrinsic enzymatic cascades. This programmable platform with reduced selective stress of antibiotics on microbiota sheds light on the potential therapy for future clinical applications.