Engineered macrophage-assisted atorvastatin nanotherapy for reversing foam cell formation in atherosclerosis

Atherosclerosis currently lacks effective therapeutic strategies specifically targeting and inhibiting foam cell formation. In this study, we engineered a macrophage nanoparticle composite drug delivery system that utilizes macrophages for competitive lipid uptake, coupled with ROS-responsive statin nanoparticles aimed at inhibiting cholesterol synthesis. This integrated system embodies a "smart immunomodulatory" approach, leveraging the inherent activity and targeted capabilities of immune cells. Experimental results demonstrated that this system significantly reduced lipid accumulation within foam cells by inhibiting cholesterol uptake, promoting cholesterol efflux and inhibition of apoptosis. These effects were mediated through microenvironmental optimization and upregulation of ABCA-1 and SR-BI expression. In an APOE knockout mouse model of atherosclerosis, the system effectively lowered lipid levels, modulated inflammatory responses, and significantly reduced foam cell formation and atherosclerotic plaque development. The system enhanced Treg cell proliferation and TGF-β secretion. Moreover, the system demonstrated high biocompatibility and therapeutic efficacy, training macrophages to revert to a low-lipid and M2 phenotype. This targeted drug delivery system integrates multiple therapeutic mechanisms, including inhibition of cholesterol uptake, enhancement of cholesterol efflux, and immunomodulation, providing a promising new strategy for the treatment of atherosclerosis.