Fig. 3

IFN-γ-Exo effectively preserved cardiac function in rats with MI in vivo. A The flowchart of experimental design in vivo. B DiI-labeled Exos were injected into the infarcted heart of rats for 6 h (50 μg Exos per rat). Representative images of post-MI heart sections stained with DiI-labeled Exos (red), cTNT(green), and DAPI (blue), Scale bar = 20 μm. C Representative echocardiographic images showed heart function among the different groups on the 14th and 28th day following MI and quantitative analysis of left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) among the different groups (n = 6 for the sham group, n = 5 for MI+PBS group, n = 6 for MI+Ctrl-Exo group, n = 6 for MI+IFN-γ-Exo group). D Masson’s trichrome stained myocardial sections on the 28th day following MI in rats treated with PBS, Ctrl-Exo, and IFN-γ-Exo. Scar tissue and viable myocardium were identified in blue and red, respectively (n = 4). Data were presented as mean ± SEM. Statistical analysis was performed with one-way ANOVA followed by Bonferroni’s correction. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001