Aims: Brain tumors especially glioblastoma multiforme (GBM) treatment is still challenging due to the lack of efficient drug delivery systems. Using exosomes as nano-sized, immunologically silent, blood-brain-barrier permeable, and natural delivery tool is a game changer in delivering apoptosis-inducing agents to GBM.
Methods: The modified exosomes harboring two gene therapy agents i.e cytosine deaminase (CDA) and miR-34a, were isolated by total exosomes isolation kit (precipitation-based) from umbilical cord mesenchymal stem cells (UCMSC) and delivered to patient-derived primary GBM cells. WK1 early passage patient primary GBM cells, represented a cell model for GBM tumors as these primary GBM cells have the heterogenous behavior of tumor environment.
Results: Exosomes were characterized for their size, morphology, protein content, and markers using dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) (around 110 nm), cryoTEM (spherical shape vesicles with a membrane thickness of 6.5 nm), western blotting (CD81, Alix, TSG101), respectively. Apoptosis flow cytometry results showed cell death rate of about 53%, 64%, and 72% in WK1 cells exposed to CDA, miR-34a, and CDA-miR34a containing exosomes, respectively.
Conclusion: The experimental findings clearly show the effectiveness of drug delivery using engineered apoptosis-inducing exosomes and also reveal the improved apoptosis in the combination therapy approach compared to single therapy.