Direct quantification of transendothelial electrical resistance in organs-on-chips.
Measuring transendothelial or transepithelial electrical resistance (TEER) is a widely used method to monitor cellular barrier tightness in organs-on-chips. Unfortunately, integrated electrodes close to the cellular barrier hamper visual inspection of the cells or require specialized cleanroom processes to fabricate see-through electrodes. Out-of-view electrodes inserted into the chip's outlets are influenced by the fluid-filled microchannels with relatively high resistance. In this case, small changes in temperature or medium composition strongly affect the apparent TEER. To solve this, we propose a simple and universally applicable method to directly determine the TEER in microfluidic organs-on-chips without the need for integrated electrodes close to the cellular barrier. Using four electrodes inserted into two channels - two on each side of the porous membrane - and six different measurement configurations we can directly derive the isolated TEER independent of channel properties. We show that this method removes large variation of non-biological origin in chips filled with culture medium. Furthermore, we demonstrate the use of our method by quantifying the TEER of a monolayer of human hCMEC/D3 cerebral endothelial cells, mimicking the blood-brain barrier inside our microfluidic organ-on-chip device. We found stable TEER values of 22 Ω cm(2)±1.3 Ω cm(2) (average ± standard error of the mean of 4 chips), comparable to other TEER values reported for hCMEC/D3 cells in well-established Transwell systems. In conclusion, we demonstrate a simple and robust way to directly determine TEER that is applicable to any organ-on-chip device with two channels separated by a membrane. This enables stable and easily applicable TEER measurements without the need for specialized cleanroom processes and with visibility on the measured cell layer.
BIOS Lab on a Chip group, MIRA Institute for Biomedical Technology and Technical Medicine & MESA, Institute for Nanotechnology, University of Twente, P.O. box 217, 7500 AE Enschede, The Netherlands. Electronic address: m.w.vanderhelm@utwente.nl.
Marinke W
MW
van der Helm
BIOS Lab on a Chip group, MIRA Institute for Biomedical Technology and Technical Medicine & MESA, Institute for Nanotechnology, University of Twente, P.O. box 217, 7500 AE Enschede, The Netherlands.
Mathieu
M
Odijk
Microsystems, Eindhoven University of Technology, P.O. box 513, 5600 MB Eindhoven, The Netherlands.
Jean-Philippe
JP
Frimat
Applied Stem Cell Technologies, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. box 217, 7500 AE Enschede, The Netherlands.
Andries D
AD
van der Meer
BIOS Lab on a Chip group, MIRA Institute for Biomedical Technology and Technical Medicine & MESA, Institute for Nanotechnology, University of Twente, P.O. box 217, 7500 AE Enschede, The Netherlands.
Jan C T
JCT
Eijkel
BIOS Lab on a Chip group, MIRA Institute for Biomedical Technology and Technical Medicine & MESA, Institute for Nanotechnology, University of Twente, P.O. box 217, 7500 AE Enschede, The Netherlands.
Albert
A
van den Berg
BIOS Lab on a Chip group, MIRA Institute for Biomedical Technology and Technical Medicine & MESA, Institute for Nanotechnology, University of Twente, P.O. box 217, 7500 AE Enschede, The Netherlands.
Loes I
LI
Segerink
D015374:Biosensing Techniques / Q000295:instrumentation*; D001812:Blood-Brain Barrier / Q000166:cytology*; D018929:Cell Culture Techniques / Q000295:instrumentation*; D002460:Cell Line; D017097:Electric Impedance; D042783:Endothelial Cells / Q000166:cytology*; D004867:Equipment Design; D006801:Humans; D056656:Lab-On-A-Chip Devices
Blood-brain barrier on chip; Microfluidics; Organs-on-chips; Transendothelial electrical resistance; Transepithelial electrical resistance