Transmission Electron Microscopy (TEM)

The size and morphology of sEVs were resolved by TEM. Briefly, 20–50 μL drop of the suspension was loaded onto a 200-mesh copper-coated grid for 15–30 min in a dry environment, fixed with 2% glutaraldehyde for 15 min, and the grids were rinsed four times in 100 μL MilliQ water. sEVs were stained for 10 min via a 30 μL drop of 2.5% uranyl acetate and excess liquid was removed using filter paper. Imaging was performed at 120 kV with JEOL-JEM 1200EX II Transmission Electron Microscope (Tokyo, Japan) (available at Cairo University Research Park, Faculty of Agriculture). Images were captured using a 4k*4k image resolution Eagle CCD camera.