Advances in Research on Blood-Brain Barrier and Its Model in Vitro

Blood-brain barrier (BBB) is a dynamic interface between the blood circulation system and the central nervous system. It mainly consists of brain microvascular endothelial cells, astrocytes, pericytes, a series of transporters and tight junction proteins. They form a dense barrier, which maintains the homeostasis of the brain's internal environment, yet also makes it difficult to develop drugs acting on the central nervous system. The in vitro model of BBB has the advantages of low cost, easy operation and controllable conditions, which can predict the results of in vivo experiments to a certain extent, reduce the cost of the experiment, be more ethical, and be used to study the pathophysiology of the brain and to screen drugs. This article reviews the composition of the blood-brain barrier, the cells commonly used in the in vitro BBB model and their characteristics, with an aim to provide some reference for the construction of the blood-brain barrier model in vitro.