Narges Mardi
1,2 
, Amir Zarebkohan
3, Cigir Biray-Avci
4, Reza Rahbarghazi
5, Mehdi Talebi
5,6, Hamid Lotfimehr
5, Sharareh Khavandkari
7, Zahra Abbasi-Malati
5, Nastaran Sedghi-Samarkhazan
8, Elham Shahriyari
4, Asghar Khalilnezhad
4, Morteza Milani
1* 
, Mohammad Nouri
1*
1 Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
2 Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
3 Department of Medical Nanotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
4 Department of Medical Biology, Faculty of Medicine, Ege University, Izmir, Turkey
5 Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
6 Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
7 Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
8 Department of Biology, Faculty of Science, University of Guilan, Rasht, Iran
Abstract
Introduction: Triple-negative breast cancer demonstrated high metastasis and mortality rates in female populations. Emerging data on effective targeting and specific internalization of chemotherapeutic agents, using modified exosomes, decreased the therapeutic dosage of anti-cancer drugs in cancer cells.
Methods: Herein, we developed modified exosomes by surface decoration using the Fusion protein of Respiratory Syncytial Virus (F-protein of RSV) through Click-chemistry techniques, and Dox-loaded via sonication strategy. Then, the viability and metastatic behaviors of MDA-MB-231 cells were monitored in the presence of different groups, including Dox, Exosomes (Exo), Exosomes loaded with Dox (Exo@Dox), and F-protein coupled Exosome groups (Exo-F) and (Exo-F@Dox).
Results: In vitro and in vivo results verified that the F-protein coupled exosome, as a modified natural nanoplatform, possessed a biocompatible nature in blood circulation and crossing of blood barriers. After exposure to tumoral temperature (40 °C) and lysosomal PH (5.5) demonstrate amplified Dox release (around 60% at 8 h). Also, in vitro uptake results confirmed a significant increase in Exo-F internalization compared to the Exo group in MDA-MB-231 cells (P<0.0001). Correspondingly, the IC50 value of Exo-F@Dox versus free Dox showed a significant reduction (24-fold more potent) (P<0.0001). Interestingly, Dox-free modified Exo (Exo-F) showed appreciable cytotoxicity (IC50 of about 0.1 µg /mL for exosomal protein concentration) (P˂0.0001). Also, migration assay results confirmed a considerable decrease in the migrated population of MDA-MB-231 cells (10%) compared to the control group, following exposure to modified exosomes. Interestingly, an in vivo study in tumor-bearing Balb/c mice demonstrated a significantly decreased tumor size in the Exo-F groups compared to other formulations.
Conclusion: In summary, F-protein modified exosomes exhibited superior anticancer efficacy by improving tumor-specific targeting, ensuring precise delivery of chemotherapeutic agents, facilitating efficient drug release, and allowing for lower therapeutic dosages.