Atherosclerotic cardiovascular disease (CVD) represents a serious affliction affecting millions globally. Despite recent advances in pharmacological and percutaneous interventions, CVD remains the leading cause of death and disability in the world. One of the main therapeutic challenges facing atherosclerotic CVD is the delivery of therapies to the atherosclerotic plaque that target the specific cells which contribute to its formation, while protecting the endothelium. Vascular endothelial cells provide crucial protection against lipid uptake, inflammation and thrombosis. We hypothesize that cell-selective therapy that inhibits infiltration of inflammatory cells and proliferation of vascular smooth muscle cells, while protecting endothelia cell function will be effective in combating CVD and thrombosis. To achieve this goal, we will develop a novel miRNA switch that combines synthetically modified mRNA with miRNA target site. As a delivery platform we will utilize the cationic amphipathic cell-penetrating peptide that forms a self-assembled, compacted, nanoparticle when mixed with synthetic mRNA. Moreover, to increase the targeting of inflammation in the atherosclerotic plaque, we will combine the miRNA switch together with siRNA targeting IL1-β to generate nanoparticles using the same cationic amphipathic cell- penetrating peptide. In two specific aims, we will test 1) the efficacy of this cell-selective nanotherapy to inhibit atherosclerosis and restenosis after percutaneous intervention, while protecting EC to reduce thrombosis; and 2) the translational potential of the miRNA switch nanotherapy in viable, isolated human coronary arteries. Completion of the aims will provide the foundation for the development of a novel category of biological drugs that can accommodate the advent of personalized medicine and will advance the treatment of cardiovascular disease.