Abstract 17087: Mesenchymal Stem Cell-Derived Extracellular Vesicle Therapy Delivered in a Hydrogel Preserves Hemodynamic Function Following Myocardial Infarction

Abstract

Introduction: Mesenchymal Stem Cell (MSC)-derived Extracellular Vesicles (EVs) are an emerging regenerative therapy for treatment of ischemic cardiomyopathy. In this study, we determine the efficacy of MSC-EV therapy in a shear-thinning hydrogel (STG) delivered via intramyocardial injection to the border zone of rat hearts following myocardial infarction (MI). Hypothesis: MSC EV-loaded STGs will preserve hemodynamic function and minimize ventricular scar formation in a rat model of acute MI. Methods: EVs were isolated from MSCs by PEG precipitation, and the EV proteome was characterized by MaxQuant 1.5.1.2 and Metacore analysis software. Varying concentrations of EVs were administered to rats following induction of acute MI by ligation of the left anterior descending artery. EVs were delivered in either sterile phosphate buffered saline (PBS) or STG for sustained EV release. Chronic injury was assessed at 4 weeks post-MI through transthoracic echocardiography, intraventricular pressure-volume loop displacement, and histology. Results: MSC EV proteomic analysis highlighted upregulation of VEGF angiogenic cascades and ILK-mediated proliferative pathways. The mean left ventricle ejection fraction (LVEF) for each treatment group at four weeks is displayed in Table 1. A 20 ug dose of MSC EVs in STG improved LVEF by 19.12% (p<0.05) compared to PBS, with a 90 ug dose of MSC EVs in STG increasing LVEF by 23.56% (p<0.01) (Fig. 1). Conclusions: Intramyocardial injection of MSC EVs in STG post-MI showed concentration dependent improvements in hemodynamics. These findings show that high doses of MSC EV in STG may have potential as a therapy for ischemic cardiomyopathy. Proteomic analysis revealed that angiogenesis, recruitment of cardiac progenitor cells, and immune modulation may be mechanistic drivers of MSC-EV therapy.