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

2021 ◽  
Vol 11 (12) ◽  
pp. 5584
Author(s):  
Nina Choublier ◽  
Yoann Müller ◽  
Loris Gomez Baisac ◽  
Jeremy Laedermann ◽  
Casimir de Rham ◽  
...  
Keyword(s):  
Shear Stress ◽  
Cell Differentiation ◽  
Blood Brain Barrier ◽  
Drug Transport ◽  
Lucifer Yellow ◽  
Cell Types ◽  
Brain Barrier ◽  
Permeable Membrane ◽  
Blood Brain

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.

scholarly journals Drug transport across the blood–Brain barrier: In Vitro and In Vivo techniques

Drug Delivery ◽  
1998 ◽  
Vol 5 (2) ◽  
pp. 153-153 ◽  
Author(s):  
de Boer A. G ◽  
W. Sutanto ◽  
William M. Pardridge
Keyword(s):  
Blood Brain Barrier ◽  
Drug Transport ◽  
Brain Barrier ◽  
Blood Brain

scholarly journals A three-dimensional model of the human blood-brain barrier to analyse the transport of nanoparticles and astrocyte/endothelial interactions

F1000Research ◽  
2016 ◽  
Vol 4 ◽  
pp. 1279 ◽  
Author(s):  
Peddagangannagari Sreekanthreddy ◽  
Radka Gromnicova ◽  
Heather Davies ◽  
James Phillips ◽  
Ignacio A. Romero ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Human Blood ◽  
Three Dimensional ◽  
Collagen Gel ◽  
Cell Types ◽  
Brain Barrier ◽  
Two Dimensional ◽  
Three Dimensional Model ◽  
Blood Brain

The aim of this study was to develop a three-dimensional (3D) model of the human blood-brain barrier in vitro, which mimics the cellular architecture of the CNS and could be used to analyse the delivery of nanoparticles to cells of the CNS. The model includes human astrocytes set in a collagen gel, which is overlaid by a monolayer of human brain endothelium (hCMEC/D3 cell line). The model was characterised by transmission electron microscopy (TEM), immunofluorescence microscopy and flow cytometry. A collagenase digestion method could recover the two cell types separately at 92-96% purity.  Astrocytes grown in the gel matrix do not divide and they have reduced expression of aquaporin-4 and the endothelin receptor, type B compared to two-dimensional cultures, but maintain their expression of glial fibrillary acidic protein. The effects of conditioned media from these astrocytes on the barrier phenotype of the endothelium was compared with media from astrocytes grown conventionally on a two-dimensional (2D) substratum. Both induce the expression of tight junction proteins zonula occludens-1 and claudin-5 in hCMEC/D3 cells, but there was no difference between the induced expression levels by the two media. The model has been used to assess the transport of glucose-coated 4nm gold nanoparticles and for leukocyte migration. TEM was used to trace and quantitate the movement of the nanoparticles across the endothelium and into the astrocytes. This blood-brain barrier model is very suitable for assessing delivery of nanoparticles and larger biomolecules to cells of the CNS, following transport across the endothelium.

New approaches to in vitro models of blood–brain barrier drug transport

2003 ◽  
Vol 8 (20) ◽  
pp. 944-954 ◽  
Author(s):  
Tetsuya Terasaki ◽  
Sumio Ohtsuki ◽  
Satoko Hori ◽  
Hitomi Takanaga ◽  
Emi Nakashima ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Drug Transport ◽  
In Vitro Models ◽  
Brain Barrier ◽  
New Approaches ◽  
Blood Brain

scholarly journals CD44 regulates blood-brain barrier integrity in response to fluid shear stress

2020 ◽  
Author(s):  
Brandon J. DeOre ◽  
Paul P. Partyka ◽  
Fan Fan ◽  
Peter A. Galie
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Blood Brain Barrier ◽  
Fluid Shear Stress ◽  
Small Gtpase ◽  
Brain Barrier ◽  
Fluid Shear ◽  
Blood Brain

AbstractFluid shear stress is an important mediator of vascular permeability, yet the molecular mechanisms underlying the response of the blood-brain barrier to shear have yet to be studied in cerebral vasculature despite its importance for brain homeostasis. The goal of this study is to probe components of shear mechanotransduction within the blood-brain barrier to gain a better understanding of pathologies associated with changes in cerebral blood flow including ischemic stroke. Interrogating the effects of shear stress in vivo is complicated by the complexity of factors in the brain parenchyma and the difficulty associated with modulating blood flow regimes. Recent advances in the ability to mimic the in vivo microenvironment using three-dimensional in vitro models provide a controlled setting to study the response of the blood-brain barrier to shear stress. The in vitro model used in this study is compatible with real-time measurement of barrier function using transendothelial electrical resistance as well as immunocytochemistry and dextran permeability assays. These experiments reveal that there is a threshold level of shear stress required for barrier formation and that the composition of the extracellular matrix, specifically the presence of hyaluronan, dictates the flow response. Gene editing to modulate the expression of CD44, a receptor for hyaluronan that previous studies have identified to be mechanosensitive, demonstrates that the receptor is required for the endothelial response to shear stress. Manipulation of small GTPase activity reveals CD44 activates Rac1 while inhibiting RhoA activation. Additionally, adducin-γ localizes to tight junctions in response to shear stress and RhoA inhibition and is required to maintain the barrier. This study identifies specific components of the mechanosensing complex associated with the blood-brain barrier response to fluid shear stress, and therefore illuminates potential targets for barrier manipulation in vivo.

Effects of Chlorpyrifos Exposure on Acetylcholine Metabolism across a Model Blood-Brain Barrier

2019 ◽  
Vol MA2019-02 (55) ◽  
pp. 2426-2426
Author(s):  
Ethan S. McClain ◽  
Dusty R. Miller ◽  
Jacquelyn A Brown ◽  
John P Wikswo ◽  
David E. Cliffel
Keyword(s):  
Blood Brain Barrier ◽  
Neurovascular Unit ◽  
Acetylcholinesterase Activity ◽  
Cell Types ◽  
Electrochemical Analysis ◽  
Brain Barrier ◽  
Agricultural Industry ◽  
Tight Junction Formation ◽  
Blood Brain

Organophosphate (OP) compounds, used throughout the agricultural industry as insecticides, are known to directly and irreparably alter brain function in humans. Exposure to OPs decreases acetylcholinesterase activity and leads to a buildup of acetylcholine, with chronic exposure to sub-lethal levels inducing neuropathy. This buildup of acetylcholine can be monitored through electrochemical methods to study the effects of OP toxicity. The microclinical analyzer (µCA), an in vitro microfluidic device allowing for electrochemical analysis using a screen-printed electrode, can be modified with enzymes to detect acetylcholine. Using the µCA in combination with the neurovascular unit (NVU), an organotypic model of the blood-brain barrier (BBB), can provide a better understanding of the BBB forms, functions, and responds to insults. The NVU supports all the cell types necessary for proper BBB formation (endothelial cells, astrocytes, pericytes, and neurons) and provides the flow-created shear forces for mature tight junction formation. The µCA and NVU were used study the effects of chlorpyrifos on acetylcholine concentrations present across the BBB. Understanding the effects of OP like chlorpyrifos on neurotoxicity can contributes to the assessment and treatment of chronic and acute exposure and inform policy decisions around the uses of OP pesticides in the agricultural industry.

Abstract TP86: The Ischemic Blood-brain Barrier In A Dish: Use Of Patient-derived Stem Cells To Model The Response Of The Neurovascular Unit To Oxygen-glucose Deprivation Stress

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Shyanne Page ◽  
Ronak Patel ◽  
Abraham Alahmad
Keyword(s):  
Cell Death ◽  
Ischemic Stroke ◽  
Blood Brain Barrier ◽  
Barrier Function ◽  
Neurovascular Unit ◽  
Barrier Properties ◽  
Cell Types ◽  
Brain Barrier ◽  
Blood Brain

The blood-brain barrier (BBB) constitutes a component of the neurovascular unit formed by specialized brain microvascular endothelial cells (BMECs) surrounded by astrocytes, pericytes and neurons. During ischemic stroke injury, the BBB constitutes the first responding element resulting in the opening of the BBB and eventually neural cell death by excitotoxicity. A better understanding of the cellular mechanisms underlying the opening of the BBB during ischemic stroke is essential to identify targets to restore such barrier function after injury. Current in vitro models of the human BBB, based on primary or immortalized BMECs monocultures, display poor barrier properties but also lack one or two cellular components of the neurovascular unit.In this study, we designed an integrative in vitro model of the BBB by generating BMECs, astrocytes and neurons using patient-derived BMECs from two iPSC lines (IMR90-c4 and CTR66M). We were able to obtain all three cell types from these two cell lines. iPSC-derived BMECs showed barrier properties similar or better barrier function than hCMEC/D3 monolayer (an immortalized adult somatic BMEC). Furthermore, iPSC—derived astrocytes were capable to induce barrier properties in BMECs upon co-cultures. whereas iPSC-derived neurons were capable to form extensive and branched neurites. Upon OGD stress, iPSC-derived BMECs showed a disruption of their barrier function as early as 6 hours of OGD stress and showed a complete disruption by 24 hours. Such disruption was reversed by reoxygenation. Interestingly such barrier disruption occurs through a VEGF-independent mechanism. In the other hand, iPSC-derived neurons showed a significant decrease in cell metabolic activity preceding neurites pruning. Finally, astrocytes showed the most robust phenotype, as we noted no cell death by 24 hours OGD.In this study, we demonstrated the ability to differentiate three cell types from the same patient in two iPSC lines. We also demonstrated the ability of these cells to respond to OGD/reoxygenation stress in agreement with the current literature. We are currently investigating the molecular mechanisms by which OGD/reoxygenation drive the cellular response in these cell types.

scholarly journals Hollow Fiber Membranes of PCL and PCL/Graphene as Scaffolds with Potential to Develop In Vitro Blood—Brain Barrier Models

Membranes ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 161
Author(s):  
Marián Mantecón-Oria ◽  
Nazely Diban ◽  
Maria T. Berciano ◽  
Maria J. Rivero ◽  
Oana David ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Cell Line ◽  
Blood Brain Barrier ◽  
Hollow Fiber ◽  
Water Flux ◽  
Pharmaceutical Research ◽  
Cell Types ◽  
Brain Barrier ◽  
Blood Brain

There is a huge interest in developing novel hollow fiber (HF) membranes able to modulate neural differentiation to produce in vitro blood–brain barrier (BBB) models for biomedical and pharmaceutical research, due to the low cell-inductive properties of the polymer HFs used in current BBB models. In this work, poly(ε-caprolactone) (PCL) and composite PCL/graphene (PCL/G) HF membranes were prepared by phase inversion and were characterized in terms of mechanical, electrical, morphological, chemical, and mass transport properties. The presence of graphene in PCL/G membranes enlarged the pore size and the water flux and presented significantly higher electrical conductivity than PCL HFs. A biocompatibility assay showed that PCL/G HFs significantly increased C6 cells adhesion and differentiation towards astrocytes, which may be attributed to their higher electrical conductivity in comparison to PCL HFs. On the other hand, PCL/G membranes produced a cytotoxic effect on the endothelial cell line HUVEC presumably related with a higher production of intracellular reactive oxygen species induced by the nanomaterial in this particular cell line. These results prove the potential of PCL HF membranes to grow endothelial cells and PCL/G HF membranes to differentiate astrocytes, the two characteristic cell types that could develop in vitro BBB models in future 3D co-culture systems.

scholarly journals Studying the Neurovascular Unit: An Improved Blood–Brain Barrier Model

2009 ◽  
Vol 29 (12) ◽  
pp. 1879-1884 ◽  
Author(s):  
Christoph M Zehendner ◽  
Heiko J Luhmann ◽  
Christoph RW Kuhlmann
Keyword(s):  
Blood Brain Barrier ◽  
Laser Scanning ◽  
Neurovascular Unit ◽  
Cell Types ◽  
Laser Scanning Confocal Microscopy ◽  
Brain Barrier ◽  
Scanning Confocal Microscopy ◽  
Blood Brain

The blood–brain barrier (BBB) closely interacts with the neuronal parenchyma in vivo. To replicate this interdependence in vitro, we established a murine coculture model composed of brain endothelial cell (BEC) monolayers with cortical organotypic slice cultures. The morphology of cell types, expression of tight junctions, formation of reactive oxygen species, caspase-3 activity in BECs, and alterations of electrical resistance under physiologic and pathophysiological conditions were investigated. This new BBB model allows the application of techniques such as laser scanning confocal microscopy, immunohistochemistry, fluorescent live cell imaging, and electrical cell substrate impedance sensing in real time for studying the dynamics of BBB function under defined conditions.

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