On-chip real-time impedance monitoring of hiPSC-derived and artificial basement membrane-supported endothelium

by Selleckchem | Jul 05 2023

Recent advances have shown the high sensibility of electrochemical impedance spectroscopy in real-time monitoring of cell barriers on a chip. Here, we applied this method to the investigation of human induced pluripotent stem cell (hiPSC) derived and artificial basement membrane (ABM) supported endothelial barrier. The ABM was obtained by self-assembling type IV collagen and laminin with a monolayer of crosslinked gelatin nanofibers. The hiPSCs were differentiated into brain microvascular endothelial cells (BMECs) and then plated on the ABM. After incubation for two days, the ABM-BMEC assembly was placed as a tissue insert into a microfluidic device for culture and real-time impedance monitoring over days. We found a significantly enhanced stability of the BMEC barrier in a serum-free and bromodeoxyuridine (BrdU) containing culture medium compared to the conventional culture due to the restricted cell proliferation. We also found that the BMEC barrier was sensitive to stimuli such as thrombin and that the change of the barrier impedance was mainly due to the change of the cell layer resistance. We can thus advocate this method to investigate the integrity of the cell barrier and the barrier-based assays.

Comments:

The recent study applied electrochemical impedance spectroscopy (EIS) to monitor cell barriers on a chip, specifically focusing on human induced pluripotent stem cell (hiPSC)-derived endothelial barriers supported by an artificial basement membrane (ABM). The ABM was created using a combination of type IV collagen, laminin, and crosslinked gelatin nanofibers.

In the experiment, hiPSCs were differentiated into brain microvascular endothelial cells (BMECs) and seeded onto the ABM. After a two-day incubation period, the ABM-BMEC assembly was inserted into a microfluidic device for culture and real-time impedance monitoring over several days. This allowed the researchers to observe and analyze the stability and integrity of the BMEC barrier over time.

One notable finding was that the BMEC barrier exhibited significantly enhanced stability when cultured in a serum-free medium containing bromodeoxyuridine (BrdU), which restricted cell proliferation. This contrasts with conventional culture conditions that support more robust cell growth. The restricted cell proliferation contributed to the improved stability of the BMEC barrier.

Furthermore, the researchers discovered that the BMEC barrier responded sensitively to stimuli such as thrombin. This means that when exposed to thrombin, the impedance of the barrier changed, primarily due to alterations in the resistance of the cell layer. This suggests that EIS can serve as a valuable tool to investigate the integrity of the cell barrier and to perform barrier-based assays.

In summary, the study highlights the utility of electrochemical impedance spectroscopy for real-time monitoring of cell barriers on a chip. By employing this method, the researchers were able to study the stability of the hiPSC-derived endothelial barrier on the ABM, demonstrate the benefits of serum-free and BrdU-containing culture conditions, and observe the sensitivity of the barrier to external stimuli like thrombin. These findings support the application of EIS in investigating cell barriers and conducting barrier-based assays.