Table 2.

Various types of microfluidic BBB models, their advantages, disadvantages and applications.

Model	Advantages	Disadvantages	Application	Reference
BMEC-Derived Model	•Strong barrier integrity. •High TEER values.	•High fluid to cell ratio limits BBB mimicry.	•Drug permeability screening.	[21]
Dual-Chamber Membrane Model	•Easily replicable. •Allows for segregated manipulation of either side of the chamber membrane.	•Hydrophobic molecule adsorption. •Underwhelming TEER measurements.	•Studying drug toxicity and permeability.	[53]
SynVivo chip based Brain Model	•Readymade. •Flexibility to modify for different applications. •Can capture the true variability in permeability across cellular monolayer. •Used human cerebral microvascular endothelial cells and primary human astrocytes.	•Limited possibility to use for drug permeability studies.	•Useful for studying BBB-brain interactions at cellular and molecular level.	[124]
PDMS-Based Microfluidic Devices	•Increased BBB integrity when co-cultured with astrocytes. •Astrocyte- endothelial cells interaction was noticed.	•Susceptible to shrinkage-related problems, ex: air bubbles in channels.	•Drug permeability. •Drug screening.	[126,127,128]
Multichannel with integrated impedance sensors	•Possibility of label-free real time impedance measurement. •ZO-1 and GFAP expression. •Fibronectin/Matrigel coated.	-	•Drug screening. •Drug permeability studies. •Drug toxicity studies.	[102]
Three microchannel integrated system	•Polycarbonate membrane and Polyethylene terephthalate membrane based platform. •Mouse embryonic stem cells based cortical spheroids were used.	•No option for the direct TEER measurements. •Absence of astrocytes and pericytes.	•Suitable to study the neuroinflammation.	[129]
Hydrogel based vasculogenesis BBB model	•HUVEC and astrocytes were used. •CD31, ZO-1, and GFAP expression tested.	•Used umbilical cord endothelial cells instead of brain microvascular endothelial cells.	•Screening of brain targeted pharmaceuticals.	[130]