Modeling the blood–brain barrier under neuroinflammation using a BBB-on-a-Chip

Neuroinflammation plays a crucial role in the development and progression of variousneurodegenerative diseases. Therapeutic strategies aimed at protecting physiological
functions of brain endothelial cells are being explored as potential treatments for these
conditions. It is necessary to have experimental models that accurately represent the effects
of neuroinflammation, as existing models are often not sufficiently representative of human
physiology and the specific challenges of central nervous system diseases with a vascular
pathology. Considering the need for a more accurate simulation strategy of the selective
properties and limitations of the blood–brain barrier (BBB), we established a BBB-on-a-chip
model, which consists of a co-culture of human stem cell-based brain endothelial cells and
brain pericytes, to study how BBB permeability is altered under pathological conditions and
to discover protective compounds to counteract BBB injury. Our preliminary results showed
that the thrombin–fibrinogen interaction-based hydrogel self-assembled model holds great
potential for use in preclinical studies, as it was possible to mimic BBB properties in vitro.
Brain endothelial cells formed an established vascular network visualized by PECAM
staining along with a positive signal for ɑ-smooth muscle actin for pericytes. Modeling BBB
injury with pro-inflammatory cytokines to promote neuroinflammation was successful with a
lower calcein AM signal and higher positivity for propidium iodide. This setup will be used to
test novel ways to improve BBB functions under neuroinflammation. In the future we aim to
identify and optimize new therapeutic compounds before testing them on animal or human
models.