Aim: To mechanistically prove the concept of monocyte-mediated nano drug delivery in glioblastoma (GBM).
Results: nano-doxorubicin-loaded monocytes (Nano-DOX-MC) were viable, able to cross an artificial endothelial barrier and capable of infiltrating GBM spheroids and releasing drug therein. GBM cells stimulated unloading of Nano-DOX-MC and took up the unloaded drug and released damage-associated molecular patterns. In mice with orthotopic GBM xenografts, Nano-DOX-MC resulted in much improved tumor drug delivery efficacy and damage-associated molecular patterns emission. Mechanistically, Nano-DOX was found sequestered in the lysosomal compartment and to induce autophagy, which may underlie MC's tolerance to Nano-DOX. Lysosomal exocytosis was found involved in the discharging mechanism of intracellular Nano-DOX.
Conclusion: Nano-DOX can be effectively delivered by MC in GBM and induce cancer cell damage.
Keywords: autophagy; chemotherapy; damage-associated molecular patterns; drug delivery; glioblastoma; lysosomal exocytosis; monocytes; nano-based drug.