IGF1 and myocardial infarction: Most importantly, it was noted that a single intra-myocardial injection of the PLGA-IGF-1 NPs was sufficient to prevent cardiomyocyte apoptosis (p < 0.001), reduce infarct sizes (p < 0.05), and improve LV ejection fraction (p < 0.01) 21 days post-MI.