Pathogen infection-responsive nanoplatform targeting macrophage endoplasmic reticulum for treating life-threatening systemic infection

Systemic infections caused by life-threatening pathogens represent one of the main factors leading to clinical death. In this study, we developed a pathogen infection-responsive and macrophage endoplasmic reticulum-targeting nanoplatform to alleviate systemic infections. The nanoplatform is composed of large-pore mesoporous silica nanoparticles (MSNs) grafted by an endoplasmic reticulum-targeting peptide, and a pathogen infection-responsive cap containing the reactive oxygen species-cleavable boronobenzyl acid linker and bovine serum albumin. The capped MSNs exhibited the capacity to high-efficiently load the antimicrobial peptide melittin, and to rapidly release the cargo triggered by H₂O₂ or the pathogen-macrophage interaction system, but had no obvious toxicity to macrophages. During the interaction with pathogenic Candida albicans cells and macrophages, the melittin-loading nanoplatform MSNE+MEL+TPB strongly inhibited pathogen growth, survived macrophages, and suppressed endoplasmic reticulum stress together with pro-inflammatory cytokine secretion. In a systemic infection model, the nanoplatform efficiently prevented kidney dysfunction, alleviated inflammatory symptoms, and protected the mice from death. This study developed a macrophage organelle-targeting nanoplatform for treatment of life-threatening systemic infections.