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Friday 19 January 2018, 14:30, Prof.dr. G. Berkhoff - Zaal

PhD Defence Marinke van der Helm

Electrical and microfluidic technologies for organs-on-chips - mimicking blood-brain barrier and gut tissues 

Marinke is PhD Student in the BIOS Lab-on-a-chip group, her supervisors are professor Albert van den Berg and professor Jan Eijkel from the Faculty of Electrical Engineering, Mathematics and Computer Science (EEMCS).

In this thesis the development and characterization of a microfluidic model of the blood-brain barrier (BBB-on-chip) is described. In this model, human brain-derived endothelial cells are cultured inside a polydimethylsiloxane (PDMS) chip with fluid-filled channels on the micrometer scale. The barrier function of this BBB-on-chip is measured with integrated electrodes, resulting in the transendothelial electrical resistance (TEER). The technology and theory of TEER measurements is further explored by electrical simulations using the gut-on-a-chip model of the Wyss Institute at Harvard University. These simulations provided insight into TEER measurements in organs-on-chips using both direct current signals and impedance spectroscopy. Furthermore, the effect of the formation of three-dimensional villi-structured tissue on the impedance spectra was studied, resulting in the identification of cell layer capacitance as a promising predictor of the state of villi differentiation. Lastly, the development of a multiplexed BBB-on-chip is described, in which up to eight functional BBBs can be cultured and tested simultaneously in different conditions.