Separating the central nervous system from the blood, the blood-brain barrier (BBB) maintains cerebral homeostasis. The barrier selectively modulates the movement of compounds, molecules, and ions between the blood and the brain. The tight BBB is made up of endothelial cells and fortified by pericytes and astrocytes, and inter- and intra-cellular components are crucial to retaining the barrier’s integrity. Weakened BBB integrity plays a role in a number of pathological conditions that affect the brain and can contribute to neurological diseases like Parkinson’s Disease and other neurodegenerative disorders.
Treating neurological conditions requires drugs to effectively reach molecular targets in the brain, which requires passage through the BBB. Current 2D and transwell models are highly controllable but do not provide physiologically relevant data on barrier integrity and activity comparable to in vivo functionality. Their static states also do not allow cells to grow in in vivo-like microenvironments, limiting cell morphology and function.
Microfluidic, 3-D modeling of the BBB promotes cells to assume in vivo physiology. These models can help study how dysfunction of the barrier can lead to pathological pathways. Additionally, these BBB models can help in drug screening and development as the ability of compounds to pass the barrier is assessed with biological fluid flow.