Cell targeting strategy affects the intracellular trafficking of liposomes altering loaded doxorubicin release kinetics and efficacy in endothelial cells.

Targeting nanocarrier drug delivery systems, that deliver drug payloads to the site of disease action, are frequently viewed as the future of nanocarrier based therapies but have struggled to breakthrough to the clinic in comparison to non-targeting counterparts. Using unilamellar liposomes as model nanocarriers, we show that cell targeting strategy (electrostatic, ligand and antigen) influences both the intracellular fate of the liposomes and the corresponding efficacy of the loaded drug, doxorubicin, in endothelial cells. We show that increased liposome uptake by cells does not translate to improved efficacy in this scenario but that liposome intracellular trafficking, particularly distribution between recycling endosomes and lysosomes, influences in vitro efficacy. Choosing targeting strategies that promote desired nanocarrier intracellular trafficking may be a viable strategy to enhance the in vivo efficacy of drug delivery systems.