An easy-repeat method to build a blood-brain barrier model on a chip with independent TEER detection module

Abstract

Blood–brain barrier on a chip (BBBoC) has emerged as a promising tool for high-throughput screening of central nervous system drugs. During the drug screening, it is essential to ensure high repeatability and consistency of assays in different culture units or chips with the same structures. For the assembled chip, cells are introduced into the inoculating chamber by perfusion. However, this method leads to differences between BBBoC because of the uncontrollable flow and sedimentation of the cell suspension in initial stages of cell inoculating. In this work, an inoculating-first and assembling-later method was presented to overcome the shortcoming. First, a porous membrane fixed between the PDMS brackets was made to support the cells. Then human brain microvascular endothelial cells and human astrocytes were respectively inoculated in turn onto the two sides of the porous membrane. When cells grew and occupied the porous membrane, the cell support was sandwiched between two glass substrates with microelectrodes for TEER detection. The method ensured high consistency of cell inoculating number on the porous membrane. Subsequently, a blood-brain barrier model in vitro with high trans-endothelial electrical resistance (TEER) value and expression of ZO-1 was achieved.