Research / 2022 / Article / Fig 5

Research Article

Glymphatic System and Subsidiary Pathways Drive Nanoparticles Away from the Brain

Figure 5

(a) Illustration of the BBB model construction in transwell chamber, the medium and cells were subjected to permeability or uptake analysis after incubation with the AuNCs. The permeability of AuNC@BSA (b) and AuNC@GSH (c) from bEnd.3 to U251 cells, and that of the two AuNCs from U251 to bEnd.3 cells (d, e, respectively). The results of uptake inhibition evaluated the uptake mechanisms of AuNC@BSA (f) and AuNC@GSH (g). According to literatures, amiloride inhibits the Na-K-ATPase to block macropinocytosis, chlorpromazine blocks clathrin-mediated endocytosis, genistein blocks caveolin-mediated endocytosis, and methyl-β-cyclodextrin (M-beta-CD) inhibits both lipid raft and caveolin-mediated endocytosis, colchicine works on macropinocytosis, clathrin-mediated endocytosis and others. The competitive inhibition by free BSA or GSH on the uptake of AuNC@BSA (h) and AuNC@GSH (i). (j) The illustration of approach that obtained exosomes and exosomes-secretion endothelia cells by using transwell chamber. (k-l) The TEM images of endothelia cells with secreted exosomes containing AuNC@BSA and AuNC@GSH, respectively. The black arrows indicate the exosomes. The images of post-phagocytosis multivesicular bodies and exosomes were amplified. (m) The signals of AuNCs in exosomes were analyzed by the nano-flow cytometry. The fluorescent intensity of FITC revealed the amounts of AuNCs. (n-q) The FITC fluorescent intensity of exosomes increased after the transport of the AuNCs.