Fig. 6

Intramyocardial SFN-F-EXOs limits decay of left ventricular contractility of infarcted heart and reduces infarct scar size in rats. F-EXOs (1*1012 particles in 100 μl PBS) (n = 5) or SFN-F-EXOs (1*1012 particles in 100 μl PBS) (n = 5) or PBS (vehicle, 100 μl) (n = 5) was injected into the myocardium of the left ventricular (LV) region bordering the infarct zone of infarcted rat heart. A–E Transthoracic echocardiography was performed on anesthetized rats 48 h and 28 days after MI. A,C: Changes of LV ejection fraction (EF, %) and heart rate at 48 h after myocardial infarction (MI). B,D: Changes of LV ejection fraction (EF, %) and heart rate at 28 days after MI. E: Longitudinal fold change (%) of LV Ejection fraction (LVEF) from 48 h to 28 days after MI. Graphs represents the mean ± SEM of five independent animals per group. *p < 0.05 vs PBS, #p < 0.05 vs F.EXOs. F–G At 28 days after myocardial infarction (MI), heart was explanted, fixed (10% formalin) and paraffin embedded. Serial sections of 7 μm thickness were stained with Masson’s Trichrome staining. Representative images of Masson’s trichrome staining 1 mm apart at three different levels of the left ventricle are shown for each experimental group. Collagen-rich areas (scar tissue) appear in blue and myocardium appears in red (G). Percentage of scar size was calculated by normalizing the scar area (blue) for the total area of the left ventricular section. Bar chart represents the mean % infarct scar size ± SEM. Each value results from analysis on three LV sections (F). *p < 0.05