Abstract 354: Optimization of Extracellular Vesicles Isolation From Cardiac Mesenchymal Cells

Background: Cell therapy and cell derived extracellular vesicles (EVs) are promising treatment options for ischemic cardiomyopathy. Despite this increasing interest, the isolation of EVs is not standardized. The purpose of this study was to compare two most common methods of EV isolation, ultracentrifugation (UC) and polyethylene glycol precipitation (PEG); and also to test the hypothesis that PEG precipitation followed by UC (PEG+UC) offers a more efficient method of EV isolation compared to PEG precipitation or UC alone. Methods: EVs were isolated from mouse cardiac mesenchymal cells by either PEG, UC (2 cycles at 100,000g, 1 hour each), or PEG+UC (100,000g for 1 hour). Size analysis, protein content measurements and western blots (WB) were performed. Results: PEG precipitation yielded three distinct population of particles (~20-60nm, ~90-500nm & >1000nm – Figure 1A). UC and PEG+UC provided one distinct population of EVs (90-500nm). With PEG precipitation, the highest concentration of particles obtained...