Mycobacterial Lipid-Coated Mesoporous Silica Nanoparticles Enable "Trojan Horse" Delivery of Isoniazid for Enhanced Intracellular Mycobactericidal Activity

Tuberculosis (TB), caused by Mycobacterium tuberculosis ( Mtb ), a paradigmatic intracellular pathogen that is adept at evading host defenses and establishing persistence within macrophages, poses a significant public health threat. Herein, we developed a novel nanoplatform (INH@LMSN) using lipids from Mycobacterium smegmatis ( M. smegmatis ), a nonpathogenic substitute for Mtb , to coat mesoporous silica nanoparticles (MSNs) for isoniazid (INH) delivery. This platform targets macrophages, releases INH in a pH-dependent manner, and enhances antibacterial activity in vitro by damaging bacterial membranes and generating reactive oxygen species (ROS). INH@LMSN also polarizes macrophages to the M1 phenotype, aiding in the intracellular mycobacteria clearance. In a mouse model of M. smegmatis infection, INH@LMSN reduced bacterial burden and alleviated pulmonary inflammation, demonstrating a dual-action strategy combining immune modulation with targeted antituberculosis drug delivery. This study provides a novel dual-action "Trojan Horse" strategy that combines pathogen lipid-mediated immune response modulation with targeted antituberculosis drug delivery, offering a promising approach to enhance intracellular mycobacterial killing and advance TB therapeutics.