Polysorbate-80 coating enhances uptake of polybutylcyanoacrylate (PBCA)-nanoparticles by human and bovine primary brain capillary endothelial cells

Certain drugs such as dalargin, loperamide or tubocurarine are not transpor ted across the blood-brain barrier (BBB) and therefore exhibit no effects o n the central nervous system. However, effects on the central nervous syste m can be observed when these drugs are loaded onto polybutylcyanoacrylate ( PBCA)-nanoparticles and coated with polysorbate 80. The mechanism by which these complexed nanoparticles cross the BBB and exhibit their effects has n ot been elucidated. Cultured microvessel brain endothelial cells of human a nd bovine origin were used as an in vitro model for the BBB to gain further insight into the mechanism of uptake of nanoparticles. With cells from the se species we were able to show that polysorbate 80-coated nanoparticles we re taken up by brain endothelial cells much more rapidly and in significant ly higher amounts (20-fold) than uncoated nanoparticles. The process of upt ake was followed by fluorescence and confocal laser scanning microscopy. Th e results demonstrate that the nanoparticles are taken up by cells and that this uptake occurs via an endocytotic mechanism.