Improved uptake of exosomal doxorubicin.

(a) HEK293 cells were incubated with different concentrations of free doxorubicin (Dox) or exosomal doxorubicin (Exo-Dox) in duplicate at 37 °C for 4 h. Uptake was analysed by flow cytometry, average mean fluorescence intensity (MFI) values were calculated and normalised to the MFI value obtained by incubating cells with an equivalent volume of PBS as control (b) HEK293 cells were incubated with free doxorubicin (Dox) or exosomal doxorubicin (Exo-Dox) for 4 h either at 37 °C or on ice in duplicate. Uptake was analysed by flow cytometry as described in a) n = 3; data is presented as mean +/-SD *p<0.05 and ****p<0.0001, ns non significant.