Fig. 4.

RBCEVs are taken up by breast cancer cells in vivo. a Schema of an in vivo EV uptake assay. b Total radiance efficiency of PKH26 fluorescence in the tumors 24 to 72 h after an intratumoral injection of 16.5 × 10¹¹ PKH26-labeled RBCEVs, determined using an in vivo imaging system (IVIS), presented as mean ± SEM (n = 3 mice). c Images of the mice bearing untreated tumors on the right flank and tumors injected with PKH26 -labeled EVs on the left flank, 72 h post-treatment, captured using IVIS. PKH26 is shown in pseudocolored radiance. d Images of the tumors excised from the mice in c. e Representative confocal microscopy images of tumor sections with DAPI stained nuclei and PKH26 signals from the cells with EV uptake. Scale bar, 20 µm