Experimental Studies On Local Injection With PLGA-PEG Scaffold Incorporating Angiopoietin1 Loaded Nanoparticles On Heart Of Infarcted Rats

Objective To investigate the effect of PLGA-PEG scaffold incorporating Angiopoietin 1 loaded nanoparticle injected into the infarcted area of rat heart to protect the heart from infarction so that to approach the mechanism of this effect on the restoration of cardiac mechanism after myocardial infarction.Methods Rat models of myocardial infarction was replicated by ligating the left anterior descending coronary artery,and one week later SD rats with similar LVEF were randomly divided into 3 groups,Ang1-PLGA-PEG injection group(injected with 100mL Nanoparticle suspension(about 1.61±0.05 mg Ang1))(n=9),Ang1 injection group(injected with PBS solution of angiopoietin1(100mL,25 ng/mL))(n=8),the model control group(injected with 100mL PBS solution)(n=8).4weeks after injection,cardiac function was identified simultaneously by echocardiography,scar tissue hyperplasia was also can be detected by Masson staining,and cardiomyocyte apoptosis and angiogenesis were detected by immunofluorescence.Results In comparison with other two groups,Ang1-PLGA-PEG injection group was increase blood vessel density in the infarcted area and maturity(P(27)0.05),and inhibits cardiomyocyte apoptosis(P(27)0.05),reduced the size and area of myocardial infarction(P(27)0.05)and infarct expansion index(P(27)0.05),increased the relative scar thickness(P(27)0.05),and sufficient to improve cardiac function(P<0.05)in a statistically significant way.Conclusion Injection of Ang1-PLGA-PEG nanoparticles into the infarcted area of the left ventricle may promote vascular proliferation and facilitate the survival of cardiomyocytes,It provides experimental basis for clinical application.