Clinically relevant dosing of miR-145 micelles curbs atherosclerosis in vivo.

Cardiovascular disease (CVD) is the leading cause of death worldwide. Atherosclerosis or plaque buildup in the arterial walls is the most common cause of CVD. For atherosclerosis, statins and PCSK9 inhibitors are prescribed to patients to lower circulating low-density lipoprotein (LDL) cholesterol. However, lowering LDL does not reduce the risk of cardiovascular events, such as myocardial infarction (MI) and stroke, for all patients. Targeting phenotypic switching of plaque-resident cells offers an alternative therapeutic strategy. To that end, we previously showed microRNA-145 (miR-145) incorporated into monocyte chemoattractant protein 1 (MCP-1) peptide amphiphile micelles bind CC chemokine receptor 2 (CCR2) that is upregulated in synthetic vascular smooth muscle cells (VSMC) and activated endothelial cells (ECs) during atherosclerosis. Previously, miR-145 micelles delivered in murine ApoE-/- models of early and mid-stage atherosclerosis showed therapeutic promise when administered at frequent intervals (one injection every three days for 15 days), common to preclinical studies. However, to evaluate the therapeutic feasibility using a dosing schedule that is practical in the clinic, herein, we evaluated the therapeutic efficacy of miR-145 micelles dosed every three weeks (four injections over 12 weeks), matching a schedule similar to FDA-approved RNA therapies. We found that miR-145 micelles reduced plaque growth in the descending aorta, reduced weight gain, lowered circulating LDL, and stabilized plaque by reducing pathogenic cell populations of VSMCs, ECs, and macrophages. Moreover, when compared to statins, miR-145 micelles inhibited pro-inflammatory VSMCs, ECs, and macrophages to a greater degree and reduced serum LDL to a similar effect. Importantly, miR-145 micelles showed no signs of toxicity or immunogenicity upon histological, immunoglobulin, and liver function analyses. Lastly, miR-145 micelles stored up to one year in 4 °C showed long-term stability and sustained therapeutic function in vitro without the need for ultra-low temperatures common in RNA therapeutic storage. These findings demonstrate miR-145 micelles are practical as an RNA-based therapy and provide feasibility of their development as a treatment for cardiovascular disease.