Yeast-derived vacuoles as a novel carrier with enhanced hCMEC/D3 cell monolayer penetration

The blood-brain barrier (BBB) is a brain protection structure that restricts drug delivery from the blood to the central nervous system. Thus, we developed a novel drug carrier using yeast vacuoles to overcome this problem. The purpose of this study was to assess the drug transportability of yeast vacuoles using the hCMEC/D3 cell monolayer. Here, we used daunorubicin (DNR) as a microtubule-targeting agent with the ability to disaggregate pre-formed fibrils and prevent Tau fibrillization. The in vitro model of the hCMEC/D3 cell monolayer was developed by culturing the human cerebral microvascular endothelial cell line (hCMEC/D3) on Transwell inserts in EBM-2 endothelial basal medium until the cells formed a monolayer. Next, the nano-sized yeast vacuole was loaded with DNR, and the signals inside and outside the hMEC/D3 cell monolayer were detected using the GloMax^® Explorer fluorometer. DNR penetrated the cell monolayer and was regulated by endocytosis via receptor-mediated macropinocytosis on the surface of the cell. Confocal imaging showed a significant increase in intracellular DNR fluorescence when the cells were treated with the vacuole-encapsulated drug. These results indicate that the drug penetrated the hCMEC/D3 cell monolayer via encapsulation into the vacuoles. Overall, yeast-derived vacuoles are promising candidates as drug carriers to the brain. Optimization of drug (daunorubicin) encapsulation into yeast vacuole The uptake of daunorubicin-loaded vacuole into hCMEC/D3 cells The assay identifies the activity of vacuole as drug delivery in hCMEC/D3 cells A mechanism of yeast vacuoles enhances the drug delivery across hMEC/D3 cell monolayer. This article is protected by copyright. All rights reserved.

blood-brain barrier penetration; daunorubicin; drug carrier; neurodegenerative disease; yeast vacuole.