Combining Physiological Relevance and Throughput
for In Vitro Cardiac Contractility Measurement
A. Brüggemann1, R. Knox2, M. Goßmann3, U. Thomas1, A. Horváth1, E. Dragicevic1, S. Stölzle-Feix1, N. Fertig1, A. Jung4, A.H. Raman4, M. Staat4 and P. Linder3
1 Nanion Technologies GmbH, Ganghoferstraße 70a, 80339 Munich, Germany; 2 Nanion Technologies Inc., Livingston, NJ, USA; 3 innoVitro GmbH, Artilleriestraße 2, 52428 Jülich, Germany; 4 Institute of Bioengineering, FH Aachen University of Applied Sciences,Heinrich-Mußmann-Str. 1, 52428 Jülich, Germany

FLEXcyte 96 Platform

Electromechanical model simulation

Contractility data derived from hiPSC-CMs in an environment that reflects the mechanical properties of real human cardiac tissue ina higher throughput format (FLEXcyte 96) is physiologically relevant.

The measurements were complemented with electromechanical models basedon electrophysiological recordings of the used cell types. Electrophysiologicalproperties were recorded by automated patch-clamp (Patchliner) and results
integrated into the electromechanical model (Jung & Staat, GAMM-Mitt., 2019; e201900002).

Introduction

FLEXcyte 96 technology allows : contractility and contraction force on flexible substrate physiological environment & label-free measurements
Principle Measurement

 Accurate detection and quantification of inotropic andchronotropic effects

FLEXcyte 96 Platform predictive recordings for early stage drug testing

4 to 8 channels
automated patch clamp system

Workflow of the Simulation Process

Mean Beat Analysis

Acute Effects ofPositive Inotropic Compounds

Contraction amplitude and velocityof hiPSC-CMs on the FLEXcyte 96(a)adapted from Sala, L., et al. 2018. Circ. Res. 122(3): e5–e16

The Patchliner

 validated for hiPSC cardiomyocytes

FLEXcyte 96 well plate(a) provides a reliable model for adult tissue-specific function

(a)

(a)

(b)

(b)

Chronic cardiotoxic effects

120%
100%
80%

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60%
40%
20%
0%

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Nilotinib 10 µM
Gefinitib 10 µM
A-674563 1 µM
control
y1
ad(b)

(b)

Acute Cardiotoxic Effects

Chronic Cardiotoxicity Detectionam plitude norm alized to control

Despite increasing acceptance of humaninduced pluripotent stem cell-derived
cardiomyocytes (hiPSC-CMs) in safety
pharmacology,
controversy
remains
about the physiological relevance ofexisting in vitro models for theirmechanical testing. We hypothesize thatexisting signs of immaturity of the cell
models, e.g. negative inotropy upon
adrenergic stimulation, result from animproper mechanical environment. We
cultured hiPSC-CMs in a 96-well format on
hyperelastic silicone membranes imitating
their native mechanical environment,
resulting in physiological responses tocompound stimuli.

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2yda

3yda

4yda5Arrhythmia

Acute effects of digoxin on hiPSC cardiomyocytes (Nexel - Cardiosight-S®). (a)Overlay of mean beats at 60 min after application of several digoxin concentrations(1 nM – 10 µM). (b) Bar graphs indicate development of beating amplitude over 60
min for the same digoxin concentrations as in (a). Bar graphs represent mean±SEM.

Conclusion
In summary, the FLEXcyte 96 system is a reliable high throughput
tool for in vitro cardiac contractility research, providing the userwith data obtained under physiological conditions which
resemble the native environment of the human heart. We showthat the results obtained for both acute and chronic compound
administration
show
consistencywiththerespective
physiological responses in humans.

(c)
Recorded on
FLEXcyte 96

Contraction and velocity profile of hiPSC-CMs (Nexel,Cardiosight-S®) grown on the flexible substrate of the FLEXcyte 96(b) are highly comparable to adult cardiomyocytes (a)indicating a more mature phenotype of these cells (adapted fromSala, L., et al. 2018. Circ. Res. 122(3): e5–e16).

ß-adrenergic agonist isoproterenol, L-type calcium channel
agonist S-Bay K8644, and cardiac myosin activator omecamtiv
mecarbil induced significant positive inotropic responses without
additional external stimulation (a). These positive inotropic
compounds induce an increase in beating amplitude (b) but
show distinct effects on beating shape, upstroke and downstroke
duration (c). Data recorderd from hiPSC-CMs (FCDI - iCell®
Cardiomyocytes2 and Nexel - Cardiosight-S®). Bar graphs
represent mean±SEM.

Chronic treatment with kinase inhibitors induced cardiotoxicity
during 5 day incubation (top) as well as various arrythmia types(bottom). Kinase inhibitors displayed cardiotoxic effects on afunctional level as chronic application induced significant
reduction in beat amplitude of hiPSC cardiomyocytes. The
system-integrated analysis detected quantifiable alterations inbeating shape as well as frequency and arrhythmic events.
Traces represent beating patters after distinct kinase inhibitors
were applied. Arhythmias are marked in pink. Data recorderd
from hiPSC-CMs (FCDI - iCell® Cardiomyocytes2 ).

FLEXcyte 96 Whitepaper

This research project was supported by: