Inhibition of cardiomyocyte apoptosis post-acute myocardial infarction through the efficient delivery of microRNA-24 by silica nanoparticles

MicroRNA-24 (miR-24) is an apoptosis suppressor miRNA downregulated in cardiomyocytes after acute myocardial infarction (AMI). However, due to the lack of effective delivery strategies, the role of anti-apoptotic miR-24 in cardiomyocytes post-acute myocardial infarction remains unexplored. Here, we used a silica nanoparticle-based polyelectrolyte (polyethylenimine, PEI) delivery system to study the role of miR-24. These particles with good biocompatibility could be efficiently internalized into cells and release the loaded miR-24 into the cytoplasm. As a result, the overexpression of miR-24 resulted in the inhibition of the pro-apoptotic Bim, thereby inhibiting cardiomyocyte apoptosis in vitro . Furthermore, in vivo experiments revealed that over-expressed miR-24 additionally significantly improves ventricular remodeling and cardiac function in Sprague-Dawley (SD) rats after coronary artery ligation. In summary, our novel delivery system serves as a therapeutic miRNA formulation for cardiovascular disease treatment. Silica nanoparticles, being easily surface-functionalized and suitable for carrying miRNA-24 which downregulated in cardiomyocytes after acute myocardial infarction.