Post on 23-Feb-2016
description
Impedance Spectroscopy for Toxicity Testing
Martin DominguezCronus Technologies Ltd.
Barrier Forming TissueEpithelial and endothelial cell layers form selectively permeable barriers
The ConceptGrowing cell layers on permeable membranes
The ConceptMeasuring the electrical impedance of epithelial and endothelial cell layers under physiological conditions
Understanding Impedance SpectraContributions stemming from CPE and RMED
Understanding Impedance SpectraThe formation of a plateau at mid-range frequencies is attributable to the cell layer’s resistance TER and capacitance CCL
Understanding Impedance SpectraAn increase in the resistance TER shifts the plateau upwards
Understanding Impedance SpectraAn increase in the capacitance CCL narrows the plateau
Time-Lapse Impedance Spectroscopy
The Setup
The Setup
cellZscopeAutomated cell monitoring device
Monitoring of MDCK-II CellsFormation of a differentiated cell monolayer with established cell-cell junctions
cellZscope vs. „Chopstick“ ElectrodesComparing TER values measured on MDCK-II cell layers
Long Term Monitoring of Caco-2 CellsComparing growth dynamics of different cell lines
0
20
40
60
80
100
120
140
0.0 0.5 1.0 1.5 2.0 2.5
TER
(%)
Ti me (h)
Control1mM EGTA2mM EGTA4mM EGTA
EGTA
re
move
d
EGTA
adde
d
EDTA Treatment of MDCK-II CellsEffects on the tight junction network
MBCD Treatment of MDCK-II CellsDose dependent response in TER and Ccl to cholesterol depletion
Testing the Toxicity of NanoparticlesExposure of MDCK cells to different types of particles
+ Triton X100
ControlControl
Carbon Black*
Carbon Black*
ZrO2*
ZrO2*
ZnO - NP*
ZnO - NP*
+ Particles
* 10 µg/cm²
0
20
40
60
80
100
120
140
160
180
0 5 10 15 20 25
Time (h)
TER
(%)
Data courtesy of A. Kroll, J. Schnekenburger, University of Münster, Germany
Testing the Toxicity of NanoparticlesExposure of NRK52E cells to ZnO
ControlControl
ZnO*
ZnO*
ZnO*
ZnO NP*
ZnO NP*
ZnO NP*
* 10 µg/cm²
0
20
40
60
80
100
120
0 5 10 15 20 25
TER
(%)
+ ZnO + Triton X100
Time (h)
Data courtesy of A. Kroll, J. Schnekenburger, University of Münster, Germany
cellZscopeAutomated cell monitoring device