Assessing barrier properties using impedance spectroscopy in a semi-circular, blood-brain barrier on-chip

The blood-brain barrier (BBB) is a fundamental biological structure that isolates the central nervous system from the rest of the body. We have developed a microfluidic BBB model that integrates electrodes, allowing for label-free assessment of the barrier's integrity. Unlike previous efforts, our model reflects the actual size (radius < 30 µm) and circular shape of a human brain microvessel, and achieves membrane-free separation of the basolateral and apical compartments. Using our device, we demonstrated that vitamin C contributes towards a tighter endothelium, and we transiently modulated the tightness of the cell layer by locally depleting calcium ions.