Dual-targeting exosomes for improved drug delivery in breast cancer.

Aims: The authors investigated whether displaying more than one homing peptide enhanced the tumor-targeting efficiency of exosomes. Materials & methods: Exosomes from human embryonic kidney cells (HEK293F) were engineered to display either mono- or dual-tumor-penetrating peptides, iRGD and tLyp1. Exosomes were purified via tangential flow filtration followed by ultracentrifugation. Results: When loaded with doxorubicin (Dox), the dual iRGD-tLyp1 exosomes strongly enhanced Dox uptake in both MCF-7 and MDA-MB-231 breast cancer cell lines, superior to single iRGD or tLyp1 exosomes. The dual iRGD-tLyp1 exosomal Dox was also the most potent, with IC 50 /GI 50 values being 3.7-17.0-times lower than those of free Dox and other exosomal Dox. Conclusion: Selecting appropriate combinatorial homing peptides could be an approach for future precision nanomedicine.