Neuropeptide Y3-36 incorporated into PVAX nanoparticle improves angiogenesis in a murine model of myocardial ischemia.

Neuropeptide-Y (NPY) leads to angiogenesis and remodeling of the ischemic myocardium. The objective of this study is to assess the therapeutic potential of NPY in a model of acute myocardial ischemia using a nanoparticles delivery system targeted to tissue with oxidative stress. NPY3-36 was loaded onto copolyoxalate containing vanillyl alcohol (PVAX) using a double emulsification strategy. Adult C57BL/J6 mice (n = 49) were randomly divided into PVAX-NPY3-36 (n = 22), Vehicle (Saline) (n = 16), and Sham (n = 11) groups. The ischemia to left anterior descending artery was induced in PVAX-NPY3-36 or vehicle groups. The tissue was collected at the end of two weeks after assessing the functional and echocardiographic data. There was a significant decrease in infarction size and mortality in PVAX-NPY3-36 group compared to the Vehicle group (P = 0.01 and P = 0.05). On echocardiography, there was significant improvement in contractility and diastolic parameters (P = 0.01). On pressure-volume loop there was significant increase in stroke volume (P = 0.01), cardiac output (P = 0.01) and ventricular stroke work (P = 0.01) in the PVAX-NPY3-36 group. On Western blot analysis, there was a significant increase in pro-angiogenic factors Ang-1, TGF-β, PDGF- β and its receptors and VEGF in the ischemic tissue treated with PVAX-NPY3-36 as compared to Vehicle ischemic tissue (P = 0.01, P = 0.0003, and P < 0.05 respectively). It may be possible to have targeted delivery of labile neurotransmitters NPY3-36 to the ischemic myocardium using nanoparticle PVAX and achieving angiogenesis and significant functional improvement.