Delivery of microRNA-1 inhibitor by dendrimer-based nanovector: An early targeting therapy for myocardial infarction in mice.

Myocardial infarction (MI), known to be rapidly progressed and fatal, necessitates a timely and effective intervention particularly within golden 24 h. The crux is to develop a therapeutic agent that can early target the infarct site with integrated therapeutic capacity. Finding the AT1 receptor being most over-expressed at 24 h after MI, we developed a nanovector (AT1-PEG-DGL) anchored with AT1 targeting peptide, and simultaneously armed it with specific microRNA-1 inhibitor (AMO-1) to attenuate cardiomyocyte apoptosis. In vivo imaging after IV administration demonstrated that AT1-PEG-DGL quickly accumulated in the MI heart during the desired early period, significantly outperforming the control group without AT1 targeting. Most importantly, a pronounced in-vivo anti-apoptosis effect was observed upon a single IV injection. Apoptotic cell death in the infarct border zone was significantly decreased and the myocardial infarct size was reduced by 64.1% as compared with that in MI control group, promising for early MI treatment.