Fig. 5.

Biodistribution of NRK52E cellderived sEVs in Wistar rat. A The in vivo (dorsal view) optical images represent the systemic distribution of labelled sEVs, dye only, and V-control groups. B Bar diagram representing the total radiant efficiency ([p/s]/[µW/cm2]) in both groups in a time-dependent manner. C Ex vivo imaging representing the accumulation status of labelled sEVs 24 h after injection. D The total radiant efficiency of kidney and liver of labelled-sEVs, dye only, and V-control group. E Photomicrograph representing the fluorescence imaging of a kidney section. Blue colour represents the nucleus, red colour dots representing the accumulated sEVs (indicated using a white arrow), magnification 40x, scale bar 50 µm. The control group received tail vein injection of PKH26 dye dissolved in PBS. F TEM images of the kidney cortex show accumulation of sEVs in both the V-control and treatment groups. The scale bar for the low-magnification (15000X) image is 1 µm, while the scale bar for the higher-magnification (452000X) image is 500 nm. Red arrow represents exosomes. For all analyses, three biological (n = 3) replicates were used. V-control = unlabelled sEVs injected rats, dye only = PKH26-injected rats, labelled sEVs = PKH26-labelled sEVs injected rats, control = PBS injected rats, sEVs = rats injected with sEVs of OTA-exposed NRK52E cells, TEC = tubular epithelial cells, and ES = extracellular space