Atrial fibrillation (AF) is the most common form of cardiac arrhythmia, significantly impacting morbidity and mortality worldwide. Despite its clinical significance, current AF models often rely on animal systems that fail to fully recapitulate human-specific disease mechanisms, limiting their translational potential. This underscores the need for innovative human-based models to better understand AF pathophysiology and screen potential therapeutic agents effectively.We developed a novel atrial fibrillation disease model screening assay using commercially available human induced pluripotent stem cell-derived atrial cardiomyocytes (hiPSC-aCMs, Axol Biosciences Ltd.). The assay is designed to assess AF-related functional changes in a human-relevant context, with extracellular field potential duration (FPD) as readout parameter. By inducing an AF-like phenotype in vitro, this model enables real-time evaluation of electrophysiological dynamics in human atrial cardiomyocytes, providing a 96well high-throughput platform for drug screening.HiPSC-aCMs were pre-cultured in 96well plates for 9 days before electrical tachypacing was applied at 2.5 Hz with the CardioExcyte 96 system for 24 h. After induction of an AF phenotype showing EFP duration shortening, class III antiarrhythmic drugs dofetilide, sotalol and ibutilide were applied at concentrations ranging from 100 pM – 10 μM. Analysis of the cellular responses show a concentration-dependent prolongation of the FPD, reflecting known drug effects of prolonging the cardiac action potential, helping to restore a regular beat rate.Our hiPSC-aCM based AF model presents a significant advancement for atrial fibrillation research, offering a physiologically relevant tool for investigating AF mechanisms and evaluating drug efficacy. With its focus on electrophysiology as a functional readout, this assay holds promise for identifying novel therapies with improved translational potential, accelerating the development of effective treatments for AF.

Drug-induced arrhythmias remain a significant challenge in drug development, often leading to serious cardiovascular complications and the withdrawal of approved drugs from the market. The Comprehensive in vitro Proarrhythmia Assay (CiPA) initiative aims to enhance cardiac safety assessment by leveraging human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). In this study, we evaluated the effects of 28 drugs on a well-characterized hiPSC-CMs (YBLiCardio, Yashraj Biotechnology Ltd., Mumbai, India) using Electric Field Potential (EFP) measurements. The CardioExcyte 96 system recorded extracellular signals from 96 wells, functioning similarly to microelectrode arrays. Each drug was tested at four concentrations, and the effects were analyzed based on dynamic changes in beat patterns, with QT prolongation assessed by measuring the interval between the sodium spike and T-wave. Our results demonstrated that YBLiCardio cells responded to all drugs in line with the findings from the HESI CiPA study. Notably, droperidol (173 %) and domperidone (182 %), originally classified as intermediate-risk compounds, were identified as high-risk in our model, consistent with previous findings by Nguyen et al. (2017). Additionally, YBLiCardio showed enhanced predictive accuracy for chlorpromazine. These findings highlight the potential of hiPSC-CMs for proarrhythmia risk assessment within the CiPA framework, complementing ion channel data and in silico modeling approaches. Overall, YBLiCardio provides a robust and physiologically relevant platform for predicting cardiotoxicity, supporting safer and more efficient pre-clinical drug discovery & development.

Over the past decade, commercial human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have emerged as vital tools for preclinical cardiac risk assessment, thanks to their human origin and limitless reproducibility. Commonly, mixed cell populations comprising ventricular, atrial, and nodal cardiomyocytes are used. However, diseases such as atrial fibrillation, impacting over 33 million individuals globally, underscore the urgent need for cardiac subtype-specific commercial cell lines. Here, we characterize commercially available hiPSC-derived atrial cardiomyocytes (atrial hiPSC-CMs) and compare them to hiPSC-derived ventricular cardiomyocytes (ventricular hiPSC-CMS) (both Axol Biosciences) regarding their contractile properties using FLEXcyte 96 technology. The cells were seeded on flexible 96-well plates mimicking physiological human heart conditions in vitro. Pre-compound beat characteristics were analyzed regarding beat rate and amplitude. Compound-induced effects of GPCR agonists acetylcholine and carbachol were tested regarding contractile properties including beat rate, amplitude and beat duration using a concentration range of 1 μM – 100 μM. Furthermore, ion channel modulators including S-Bay K8644, ivabradine, vernakalant and 4-Aminopyridine were assessed at 4 different concentrations ranging from 100 nM – 1 μM. Pre-compound analysis reveals cell type-specific beat shapes analogous to the respective cardiac action potential, in which atrial cells show a higher beat rate and less pronounced contraction force compared to ventricular cells. Pharmacological analysis demonstrates a higher susceptibility of atrial hiPSC-CMs towards GPCR agonists acetylcholine and carbachol than ventricular cells. Ion channel modulator S-Bay K8644 induces reversed inotropic and chronotropic effects in atrial and ventricular cells, while ivabradine causes a pronounced negative chronotropic effect in atrial cells alone. 4-Aminopyridine reveals prolonged contraction duration and reduced chronotropy in atrial hiPSC-CMs, while vernakalant induces opposing reactions in chronotropy of chamber-specific cardiomyocytes. These results underscore the significant pharmacological responses of atrial hiPSC-CMs and their utility on a multiwell contractility platform for enhancing in vitro cardiac liability studies and disease modeling.

While human induced Pluripotent Stem Cell (iPSC)-derived cardiac cell models from healthy and diseased donors promise to facilitate the analysis of drug effects in virtual cohorts during preclinical drug development, to date most human iPSC-derived cardiomyocyte models used in safety applications are derived from a small number of healthy donors. We present a proof-of-concept study on the feasibility of virtual human cohorts with variable genetic background as part of an ongoing industry and academia collaboration. Cardiomyocyte contractility parameters are analyzed by dedicated artificial intelligence algorithms supposed to recognize functional differences between individual donors, including responses to standard tool compounds. Cardiomyocytes were differentiated from healthy donors (2 female/2 male), donors with congenital LQT syndrome (4/3) and Brugada syndrome (1/2). They were either cultured as monolayers (2D) or as cardiac organoids (3D) on FLEXcyte 96 plates and analyzed for their contractile parameters by application of a dedicated AI model, consisting of 3 sub-models comprising of a series of sequential Bottleneck-Convolution-Blocks followed by a feedforward layer. This model can process 20 s long measurements (20 k datapoints measured with a frequency of 1 kHz) and perform beat detection and classification. The model can identify, locate and capture the boundaries of each beat, enabling direct analysis of the beat duration. While the contractile base parameters from 2D and 3D cultures differ significantly in a variety of beat shape parameters (including total force of contraction, contraction/relaxation duration ratio), the effects of tool compounds (E-4031, Nifedipine, isoproterenol) are largely comparable in both models. The AI model achieved an accuracy score of 99.44 % and an F1-score of 95.22 % for all predictions, indicating outstanding pattern recognition. In a next step, the AI architecture is adapted to classify more detailed arrhythmic events, e.g. early after contraction, or even diseased contraction patterns, e.g. long QT syndrome. For the final evaluation of the effect of the genetic background on the contraction parameters, more data is continuously being generated to feed the AI model.

Within classical treatment types for cancer, advancing therapies such as immuno-therapy have emerged lately. Identifying T cells that kill cancer cells in vivo and monitoring CAR-T cell activity in vitro is critical to the development of successful cell therapies. We here developed an in vitro system allowing for killing assays within immune-therapeutic efforts, and to search for pharmaceutical drugs or for cytotoxic effects of substances. The assay technology, Electric Cell-substrate Impedance Sensing (ECIS), offers possibilities to study the response of living cells to a stimulus in a label-free, time-resolved, and non-invasive manner. The impedance of planar gold-film electrodes that are used as growth substrate for cells reveals changes in e.g. electrode coverage or cell behavior. Real-time data provide insights regarding kinetics of cell responses. Advanced information content is obtained by using multi- frequency impedance readouts (0.1 kHz–100 kHz), furthermore raw impedance values including capacitance, resistance and phase are accessible. For example, high frequency impedance is sensitive to differences in cell confluency, making it useful for measuring proliferation or cytotoxicity, whereas low frequency impedance data reveal barrier integrity and allow to quantify cell adhesion. We used the A549 epithelial lung adenocarcinoma cell line that was derived from a primary lung cancer. Effector cells co-cultured in the killing assay were purified human cytotoxic T- lymphocytes. We found that after 27 h the cytolysis of A549 cells gradually increases and reaches a maximum of 37 %, 48 %, 59 % and 57 % in the presence of the target to effector cell ratio 1:2, 1:1, 2:1 and 3:1, respectively. Respective Kill Time 50 values are shown. Furthermore, we investigated H9C2 cardiac-like cells. We found that e.g. Erlotinib is, as expected, cardio-safe, whereas compounds with a different mechanism of action show toxic effects on the cells. For example, Vincristine which is interacting with tubulin proteins showed a concentration- and time-dependent effect on H9C2 cells. Our aim with the newly developed 6 × 96-well platform, AtlaZ, is to elevate live cell analysis to a next level. Being able to monitor raw impedance values including capacitance, resistance and phase over the spectrum and at this throughput is so far unmet.

Over the past decade, commercial human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) became an important tool for preclinical cardiac risk assessment owing to their human origin and unlimited reproducibility. Mixed cell populations display a commonly used set up with cardiac subtype characteristics of ventricular, atrial and nodal nature. However, diseases such as atrial fibrillation, affecting more than 33 M people worldwide, demonstrate the need for cardiac subtype-specific commercial cell lines. Here, we compare commercially available ventricular and atrial cell types (Axol Biosciences) regarding their contractile properties using FLEXcyte technology. The cells were seeded on flexible 96-well plates mimicking physiological human heart conditions in vitro. General beat shape of both cell types was analyzed and compared after six days in culture. Compound-induced effects on contractile properties including beat rate, amplitude and duration was assessed on acute basis with S-Bay K8644 at 5 different concentrations ranging from 100 nM to 1 μM as well as 4-AP and Carbachol with 5 concentrations ranging from 1 μM to 100 μM. The results demonstrate cell type specific beat shapes analogue to the respective cardiac action potential, in which ventricular hiPSC-CMs show a calcium influx-related extended plateau phase compared to atrial cells. S-Bay K8644 treatment of atrial hiPSC-CMs induced a concentration-dependent transient increase on beat duration alongside a decrease in beat rate over time, whereas ventricular cells showed a physiological increase in beat rate over time. Carbachol treatment produced marked effects on atrial cells, such as increased beat duration and downstroke duration, but only minimal effects on ventricular cardiomyocytes. 4-AP showed a reduction in beat rate and an increase in beat duration on atrial cells, while ventricular cells showed no change in beat rate and a transient reduction in beat duration. HiPSC atrial and ventricular cardiomyocytes reproduced the different contractile phenotypes and pharmacological responses of primary cardiomyocyte sub-types suitably. Hence, these cell types provide the starting point to develop more reliable, physiological-relevant research on subtype-specific cardiac diseases.

The great promise of human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs) as in vitro models for the assessment of proarrhythmic risk, was extensively studied by the Comprehensive In Vitro Proarrhythmia Assay (CiPA) initiative. Since long-term exposure of cancer-related therapeutics have been linked to alterations of cardiac function in patients, the Stem Cell Working Group as part of the Health and Environmental Science Institute (HESI) endeavors to gain further insight into chronic cardiotoxicity. The objective of the study was to optimize non-clinical safety assessment strategies of chronic cardiotoxicity by testing prolonged exposure of reference compounds on cell-based assay systems using hiPSC-CMs. Here, we present an extract of the HESI chronic cardiotoxicity study with 8 different compounds known to act via diverse mechanisms of actions (MoAs) in cardiomyocytes, affecting cardiac energetics (doxorubicin, erlotinib, sunitinib), contractility (BMS-986094, Nilotinib), electrophysiology (pentamidine), and myofilament organization (endothelin-1, vincristine). Each compound was tested on iCell Cardiomyocytes2 (FUJIFILM Cellular Dynamics Inc.) at four different concentrations over a time frame of 144 h. Changes in contractile properties were assessed using FLEXcyte technology, a 96-well assay system with specialized plates that enable monitoring cardiac contractility in a label-free manner. The results show alterations in cardiac function related to the MoA of the respective compound, as well as time- and/or dose-dependent effects. For instance, Doxorubicin and BMS 986094 treatment both exhibit a concentration-dependent decrease in amplitude over time, by acting either through mitochondrial toxicity (Doxorubicin) or impaired calcium handling (BMS 986094). This excerpt of the HESI Stem Cell Working Group study underlines the potential of in vitro systems to address contractile function of hiPSC-CMs for chronic safety pharmacological studies of compounds with diverse MoAs.

The importance of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) continues to increase in the assessment of the safety and toxicological side effects of newly developed compounds. In pre-clinical drug development, one of the crucial steps is the analysis of cardiac contraction. Utilizing hiPSC-CMs in safety and drug development faces various obstacles, such as immature phenotype, lot-to-lot variability, or the difficulty to assess drug responses without the presence of serum. Here we show a method for overcoming these limitationss. HiPSC-CMs were plated on regular, stiff plastic 96-well plates and on the silicone membranes of the FLEXcyte plates. To analyze the pro-maturation effect of the FLEXcyte technology on hiPSC-CMs, expression levels of relevant cardiac genes and phenotypic characterization via actin cytoskeleton immunostainings were performed. Additionally, functional characterization with cardio-safe and cardio-toxic compounds was performed on acute and chronic levels. Lot-to-lot consistency of commercial hiPSC-CMs (iCell Cardiomyocytes2, FCDI), as well as the effects of a defined serum-free medium on these cells, were analyzed. HiPSC-CMs from 10 different cell lots were cultured for 6 days before compound treatment. The difference in contractility behavior was compared among the cell lots. To test the effect of serum depletion, hiPSC-CMs were cultured for 6 days in either serum-free or serum-containing medium. Contractile properties were tested upon the addition of nifedipine, sotalol, erlotinib, and doxorubicin. The results show increased expression levels of cardio-specific genes as well as pronounced filamentous actin when cells are cultured on FLEXcyte plates. Cardio-safe compounds showed negative inotropic effects only at high doses, while cardiotoxic compounds showed time and dose-dependent inotropic effects, as well as arrhythmic events. Lot-to-lot consistency of iCell Cardiomyocytes2 was confirmed. A pharmacological comparison of sotalol and nifedipine showed robust results with non-significant fluctuations. Similar robust results were obtained in the serum-free study with comparable reactions of hiPSC-CMs cultured in either serum-containing or serum-free medium. The flexible membranes mimic a native-like environment that promotes cellular maturation on genetical and functional levels. The lot-to-lot consistency and the physiological compound responses of hiPSC-CMs in serum-free conditions demonstrate that FLEXcyte is a robust platform for preclinical cardiac risk assessment.

Within cancer treatments, traditional approaches have been augmented by recent advancements in therapies, particularly immuno-therapy. We have developed real-time in vitro system tailored for assessing the efficacy of immune-based therapies and for investigating pharmaceutical drugs or the cytotoxic effects of various substances. The assay technology, electric cell-substrate impedance sensing (ECIS), offers possibilities to study the response of living cells to a stimulus in a label-free, time-resolved, and non-invasive manner.

Human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (CMs) have found utility for conducting in vitro drug screening and disease modelling to gain crucial insights into pharmacology or disease phenotype. However, diseases such as atrial fibrillation, affecting >33 M people worldwide, demonstrate the need for cardiac subtype-specific cells. Here, we sought to investigate the base characteristics and pharmacological differences between commercially available chamber-specific atrial or ventricular hiPSC-CMs seeded onto ultra-thin, flexible PDMS membranes to simultaneously measure contractility in a 96 multi-well format. We investigated the effects of GPCR agonists (acetylcholine and carbachol), a Ca2+ channel agonist (S-Bay K8644), an HCN channel antagonist (ivabradine) and K+ channel antagonists (4-AP and vernakalant). We observed differential effects between atrial and ventricular hiPSC-CMs on contractile properties including beat rate, beat duration, contractile force and evidence of arrhythmias at a range of concentrations. As an excerpt of the compound analysis, S-Bay K8644 treatment showed an induced concentration-dependent transient increase in beat duration of atrial hiPSC-CMs, whereas ventricular cells showed a physiological increase in beat rate over time. Carbachol treatment produced marked effects on atrial cells, such as increased beat duration alongside a decrease in beat rate over time, but only minimal effects on ventricular cardiomyocytes. In the context of this chamber-specific pharmacology, we not only add to contractile characterization of hiPSC-CMs but propose a multi-well platform for medium-throughput early compound screening. Overall, these insights illustrate the key pharmacological differences between chamber-specific cardiomyocytes and their application on a multi-well contractility platform to gain insights for in vitro cardiac liability studies and disease modelling.

The use of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) continues to increase in the assessment of safety and toxicological side effects of newly developed compounds, due to their reproducibility and low ethical concern. In pre-clinical drug development, cardiac contraction analysis of potential drug candidates is one of the crucial steps to ensure a successful and reliable transition to clinical stages. Using hiPSC-CMs, the obstacles of an immature phenotype as well as the need of serum-containing media for chronic assays raise concerns over non-physiological responses in preclinical drug development.

Cardiac contractility assessment is of immense importance for the development of new therapeutics and their safe transition into clinical stages. While human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) hold promise to serve as a human-relevant model in preclinical phases of drug discovery and safety pharmacology, their maturity is still controversial in the scientific community and under constant development. We present a hybrid contractility and impedance/extracellular field potential (EFP) technology, adding significant pro-maturation features to an industry-standard 96-well platform. The impedance/EFP system monitors cellular functionality in real-time. Besides the beat rate of contractile cells, the electrical impedance spectroscopy readouts detect compound-induced morphological changes like cell density and integrity of the cellular monolayer. In the other component of the hybrid cell analysis system, the cells are cultured on bio-compliant membranes that mimic the mechanical environment of real heart tissue. This physiological environment supports the maturation of hiPSC-CMs in vitro, leading to more adult-like contractile responses including positive inotropic effects after treatment with isoproterenol, S-Bay K8644, or omecamtiv mecarbil. Parameters such as the amplitude of contraction force (mN/mm2) and beat duration also reveal downstream effects of compounds with influence on electrophysiological properties and calcium handling. The hybrid system provides the ideal tool for holistic cell analysis, allowing preclinical cardiac risk assessment beyond the current perspectives of human-relevant cell-based assays.

The Autonomous Pinger Unit (APU) is an electro-thermal drill with acoustic instrumentation developed for the project EnEx-RANGE in view of a future space mission for the sub-surface exploration of Saturn's moon Enceladus. A main goal is the development of navigation technology for an acoustic guidance system allowing maneuvering a probe through glacial ice. In total 13 APUs were built and tested in terrestrial analog scenarios on alpine glaciers. The APUs form a spatially distributed network that defines a system of reference for the navigation of the maneuverable probe to a point of interest. The APUs have a novel melting head, slow control systems, and a modern system-on-chip (SoC) module that controls the probe and processes the recorded data. The APUs use acoustic emitters and receivers to measure the transit time of acoustic signals between them, allowing for the position reconstruction of all APUs by trilateration. Several auxiliary sensors monitor the internal state of the probe and assist the position estimation. With this instrumentation, the APUs have the ability of dynamically optimizing themselves within the network by changing their position. This paper gives an overview of the developed APU hardware and presents performance results from the field tests.

Abstract In this paper, we present an electric-thermal drill with a novel design of a melting head that was developed within the EnEx-RANGE project. The design combines a short melting head with a large surface area of parabolic shape. It was succesfully tested in the laboratory as well as on Alpine glaciers (Langenferner and Mittelbergferner) and at the Ross Ice Shelf in Antarctica. In all these different environments, a high melting speed per specific power of typically 8.8 cm3 w−1 h−1 is achieved that is close to the ideal maximum bound of ~10.5–11.8 cm3 w−1 h−1 when neglecting all heat losses. It has also been demonstrated that the melting probe can be operated with typical equipment of small-scale field camps including a small power generator.