Blood–Brain Barrier Dynamic Device with Uniform Shear Stress Distribution for Microscopy and Permeability Measurements

Abstract

Neurology has always been one of the therapeutic areas with higher attrition rates. One of the main difficulties is the presence of the blood–brain barrier (BBB) that restricts access to the brain for major drugs. This low success rate has led to an increasing demand for in vitro tools. The shear stress, which positively affects endothelial cell differentiation by mimicking blood flow, is required for a more physiological in vitro BBB model. We created an innovative device specifically designed for cell culture under shear stress to investigate drug permeability. Our dynamic device encompasses two compartments communicating together via a semi-permeable membrane, on which human cerebral microvascular endothelial (hCMEC/D3) cells were seeded. The fluidic controlled environment ensures a laminar and homogenous flow to culture cells for at least seven days. Cell differentiation was characterized by immunodetection of inter-endothelial junctions directly in the device by confocal microscopy. Finally, we performed permeability assay with lucifer yellow in both static and dynamic conditions in parallel. Our dynamic device is suited to the evaluation of barrier function and the study of drug transport across the BBB, but it could also be used with other human cell types to reproduce intestinal or kidney barriers.

Exposure of human cerebral microvascular endothelial cells hCMEC/D3 to laminar shear stress induces vascular protective responses

“…In contrast, in our work, cells were cultivated at the bottom of a single channel. In the future, this experiment could be reproduced after cultivating hCMEC/D3 cells on a dual chamber microfluidic device composed of a semi-permeable membrane [ 91 ]. Effects of SS on BMEC of various origins was previously reported: de Stefano et al reported no clear differences between claudin-5, occludin, and ZO-1 expression/localization under static and flow conditions in derived human brain microvascular endothelial cells (dhBMECs) [ 50 ], whereas SS triggered the translocation of ZO-1 with an increased junctional intensity in primary porcine BMEC[ 92 ] and a stronger immunoreactivity of occludin and ZO-1 at cell borders in primary bovine BMEC[ 93 ].…”

A Microfluidic In Vitro Three-Dimensional Dynamic Model of the Blood–Brain Barrier to Study the Transmigration of Immune Cells

“…After successful seeding, the membrane was placed in the engineered microfluidic slide, clamped with the clamping system and was then attached to the fluidic unit of the pump. Cells were maintained under shear stress levels of 4–15 dyn/cm 2 , which are considered comparable to those reported in brain capillaries in vivo [ 37 , 38 , 39 , 40 , 41 ]. At the start of the experiment, the shear stress level was maintained at 4 dyn/cm 2 , as a greater shear stress led to the detachment of the cells from the membrane.…”

In Vitro Modeling of the Blood–Brain Barrier for the Study of Physiological Conditions and Alzheimer’s Disease

“…The principle is similar to the contact Transwell cultivation, with BMECs covering the inside of the lumen, while the other cellular components of the NVU are seeded extraluminally. The main advantage of DIV models over static co-cultures is the possibility to induce quasi-physiological shear stress, considered essential for BMECs phenotype modulation [ 92 ]. Other pros include the higher TEER, a relevant parameter when studying molecular/drug passage via the BBB [ 107 ], together with the ability to examine BBB alteration in hypoperfusion and reperfusion conditions [ 108 ].…”