The BBB model includes human cerebral endothelial cells as well as primary pericytes and astrocytes in a 3D arrangement within a pump-free, open microfluidic platform. The flow conditions mimicking the body will be set in motion with a kind of seesaw to avoid stressing the cells. A comparison with conventional models revealed that the new model exhibits a denser barrier layer. The permeability and morphological changes of the blood-brain barrier can be studied with high-resolution time-lapse microscopy. Electrical resistance is measured by transparent electrodes attached to cover glasses on either side of the barrier.

As a first test, the scientists exposed the barrier model to oxygen-sugar deprivation, as occurs during a stroke. They were able to show that the electrical resistance of the barrier breaks down even before it undergoes morphological changes and thus becomes more permeable. Live high-resolution imaging showed the formation of large actin stress fiber bundles in the endothelial layer, ultimately leading to cell shrinkage and barrier rupture.

Original publication:
Wei W, Cardes F, Hierlemann A, Modena MM: 3D In Vitro Blood-Brain Barrier Model for Investigating Barrier Insults. Advanced Science, February 13, 2023, doi: 10.1002/advs.202205752

Source:
https://ethz.ch/de/news-und-veranstaltungen/eth-news/news/2023/02/besser-verstehen-wie-die-blut-hirn-schranke-funktioniert.html