Figure 1.

Schematic of the blood-brain barrier (BBB). (A) the central endovascular cavity is surrounded by layers outward; in order, they are endothelial cell, extracellular matrix, and astrocyte synapse layers. This structure enables the BBB to filter substances thoroughly. (B) schematic of the mechanism by which substances penetrate the BBB. (C) schematic of the channel. The purple arrow represents the flow direction. The upper surface of the channel is composed of endothelial cells, whereas the lower surface comprises cultured astrocytes (not included in this experiment). The closer the fluid is to the wall surface, the slower the flow is and the greater the shear stress is.