Isolation and characterization of exosomes from placenta originating mesenchymal stem cells and investigation of its effectiveness as a drug delivery system

Aim: Mesenchymal stem cells (MSC) are tissue-derived cells with the self-renewing ability and can differentiate into various cell lineages. The placenta is a transient organ that maintains fetal tolerance and constitutes a rich reservoir of MSC. Since MSCs are readily isolated from the placenta without invasive procedures, their use does not elicit ethical concerns. The secretome of MSCs, including growth factors, cytokines, chemokines, microvesicles and exosomes has been shown to exhibit many of the therapeutic properties of MSCs. The purpose of this study is to look into the effect of exosomes released from placenta-derived mesenchymal stem cells in the treatment of cervical cancer by making them functional with docetaxel (DOC). Material and Method: Following the incubation with type I collagenase, MSCs were isolated from the placenta. CD44, CD90, CD105 and CD34 were used to identify isolated MSCs. Exosomes were isolated from the MSC starvation medium using and ultracentrifugation method every 48 hours. After centrifugation, exosome pellets were resuspended in PBS and purified by Exo-Quick exosome purification kit. Purified exosomes were characterized using particle size and structure, as well as CD9, CD63 and CD81 markers. MSC-derived exosomes were electroporated with docetaxel (EXO-DOC) and then incubated with HeLa cervical cancer cells for 24 and 48 hours. Cytotoxicity tests, western blotting and qPCR analysis were performed. Results: Scanning electron microscopy has revealed the particles size and structure of pure and docetaxel-loaded exosomes as 81 and 107 nm respectively. Docetaxel-loaded exosomes show efficacy in a shorter time and at lower concentrations. According to western blotting and qPCR results EXODOC increases apoptosis and decreases epithelial-mesenchymal transition (EMT) in HeLa cells. Conclusion: If the exosomes of placenta excreted after birth are isolated, they can be used as a drug delivery system and these exosomes facilitate drug entry into the cells, making drugs more effective at low doses. The findings of this study will help to increase the potential for using the placenta-derived exosomes in the development of new drug delivery systems for anticancer therapies. Keywords: Docetaxel, Exosome, Mesenchymal stem cell, Placenta, Cervical cancer.