Paclitaxel incorporated exosomes derived from glioblastoma cells: comparative study of two loading techniques

Background Exosomes are natural nanoparticles that are involved in intercellular communication via transferring molecular information between cells. Recently, exosomes have been considered for exploitation as novel drug delivery systems due to their specific properties for carrying specific molecules and surface proteins. Methods In this study, U-87 cell derived exosomes have been investigated for delivery of a potent chemotherapeutic agent, paclitaxel (PTX). Two methods of loading were utilized to incorporate PTX in exosomes and the exosomes pharmaceutical and cytotoxic characterizations were determined. Results The drug loaded and empty exosomes were found to have particle size of 50-100 nm and zeta potential of approximate to - 20 mV. Loading capacity of 7.4 ng and 9.2 ng PTX into 1 mu g of exosome total protein were also measured for incubation and sonication methods, respectively. Incorporation of PTX into exosomes significantly increased its cytotoxicity against U-87 cell line (59.92% cell viability) while it was found that the empty exosomes exhibited cell viability of 91.98%. Conclusions Loading method could affect the loading capacity of exosomes and their encapsulated chemotherapeutic molecule showed higher cytotoxicity into exosomes. These results promise exosomes as appropriate drug delivery systemfor glioblastoma multiform (GBM) treatment.