Fig. 4

Co-localization of Dox and CBMVs in Dox-CBMVs and on cells. a Confocal microscopy detected the co-localization of Dox and CBMVs in Dox-CBMVs deposited on glass coverslips. The CBMVs were pre-stained with Dio (a cell membrane fluorescent dye; in blue, a pseudo color). The loaded Dox was self-fluorescent (in green). b Confocal microscopic images of free Dox in the nuclei of endothelial cells (HUVECs). c Confocal microscopic images of the Dio-stained CBMVs without Dox binding on the surfaces of HUVECs. d Confocal microscopic images of the Dio-stained Dox-CBMVs binding on the surfaces of HUVECs. The cells were incubated with free Dox, the Dio-stained CBMVs, and the Dio-stained Dox-CBMVs, respectively at 37 °C for 1 h