Hypoxia-inducible factor-1α(HIF-1α),a transcription factor,is naturally degraded by prolyl hydroxylase-2(PHD2).During ischemic and reperfusion injury,the up-regulation of HIF-1α activates downstream angiogenic genes.Although gene transfection for cardiovasculardisease therapy using naked plasmid DNA or an adenoviral vector has been successful,there are unresolved problems for human gene therapy,such as low transfection efficiency and safety.