A HUMAN BBB MODEL IN AN ORGAN-ON-A-CHIP DEVICE AND THE EFFECT OF FLUID FLOW
Blood-brain barrier-on-a-chip models are cutting edge microengineered devices, but only a few combine the crucial parameters needed for in-depth analyses. Our laboratory developed an organ-on-a-chip device to study the blood brain barrier (BBB), which enables visual observation, transendothelial electrical resistance (TEER) and permeability measurements and the introduction of fluid flow. The objective of our study was to optimize a human BBB cell culture model in this organ-on-a-chip and determine the effect of the fluid flow on the barrier properties of the BBB model. The device was built up from a porous cell culture membrane sandwiched between two layers of PDMS and a top and bottom plastic slide coated with gold electrodes. A peristaltic pump was used to circulate the cell culture medium to mimic the blood flow. The stem cell derived CD34+ human endothelial cells in co-culture with bovine pericytes were cultured in the device, as a human BBB model. We optimized the co-culture of stem cell derived CD34+ human endothelial cells with bovine pericytes in the device. The resistance was measured in real time. Flow conditions elevated the TEER significantly, which was also confirmed by ZO-1 and β-catenin immunostainings. To investigate the differences after fluid flow condition a gene expression study was performed with extensive analyses of junctional protein, metabolic enzymes, efflux pump expression. This device is a cutting-edge invention in the barrier-chip field providing users with a standardized and reliable platform to perform BBB pathology and pharmacology related experiments. Grants: ETN-H2020-MSCA-ITN-2015, 675619, and NNE-129617-M-ERA.NET2 nanoPD.