Replacing Fetal Bovine Serum

The Academy for Animal Welfare and cellasys host a Symposium about Replacing Fetal Bovine Serum. It will take place on November 3rd, 2020 at the TranslaTUM in Munich and will be extended by a workshop on November the 4th.

Please find more information by clicking here.

Tissue-on-a-Chip: Microphysiometry With Human 3D Models on Transwell Inserts

Christian Schmidt1, Jan Markus2, Helena Kandarova 3,4 and Joachim Wiest 1,5*

Front. Bioeng. Biotechnol., 04 August 2020 | https://doi.org/10.3389/fbioe.2020.00760

1cellasys GmbH, Kronburg, Germany
2MatTek In Vitro Life Science Laboratories, Bratislava, Slovakia
3Centre of Experimental Medicine SAS, Slovak Academy of Sciences, Bratislava, Slovakia
4Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovakia
5Heinz Nixdorf Chair of Biomedical Electronics, Department of Electrical and Computer Engineering, Technical University of Munich, Munich, Germany

Corresponding author: wiest@cellasys.com

Microphysiometry has proved to be a useful tool for monitoring the energy metabolism of living cells and their interactions with other cells. The technique has mainly been used for monitoring two-dimensional (2D) monolayers of cells. Recently, our group showed that it is also possible to monitor the extracellular acidification rate and transepithelial electrical resistance (TEER) of 3D skin constructs in an automated assay maintaining an air–liquid interface (ALI) with a BioChip extended by 3D-printed encapsulation. In this work, we present an optimized multichannel intestine-on-a-chip for monitoring the TEER of the commercially available 3D small intestinal tissue model (EpiIntestinalTM from MatTek). Experiments are performed for 1 day, during which a 60 min cycle is repeated periodically. Each cycle consists of three parts: (1) maintain ALI; (2) application of the measurement medium or test substance; and (3) the rinse cycle. A cytotoxic and barrier-disrupting benchmark chemical (0.2% sodium dodecyl sulfate) was applied after 8 h of initial equilibration. This caused time-dependent reduction of the TEER, which could not be observed with typical cytotoxicity measurement methods. This work represents a proof-of-principle of multichannel time-resolved TEER monitoring of a 3D intestine model using an automated ALI. Reconstructed human tissue combined with the Intelligent Mobile Lab for In vitro Diagnostic technology represents a promising research tool for use in toxicology, cellular metabolism studies, and drug absorption research.

cellasys #8: A microphysiometric assay to asses enhanced cell culture media

Christian Klenk1,2 and Joachim Wiest1,2*

11th World Congress on Alternatives and Animal Use in the Life Science, Abstract overview, 2020, 33

1 cellasys GmbH, Kronburg / Germany
2 Technical University of Munich, Heinz-Nixdorf-Chair of Biomedical Electronics, Department of Electrical and Computer Engineering, TranslaTUM, Munich / Germany

Corresponding author: wiest@cellasys.com

A new protocol based on a microphyiometric system (McConnell et al., 1992, Hartung et al., 2010, Wiest et al., 2016, Alexander et al., 2018, Brischwein and Wiest, 2019) to analyze cell culture medium (CCM) is described. With the presented cellasys #8 protocol, significant data can be gained in 24 h compared to conventional weaning experiments which need several weeks to perform. First, L929 cells are supplied for 6 hours with DMEM + FBS reference medium to gain initial data. In a second step, 6 hours of the investigated test medium is supplied to see if there are any changes in cellular vitality or morphology. Then again 4 hours DMEM + FBS and 4 hours of test medium to monitor if the effect of the CCM to the cells is reversible. The experiment ends with 4 hours of test medium + 0.2% SDS to induce cell death. In the presented work, two chemically defined CCM and a common serum-containing medium DMEM + FBS were tested on the L929 cell line. Compared to the reference medium, cells in the DMEM/Ham’s F12 + ITS medium pursue a loss in adherence, but no decrease in extracellular acidification rate. This was substantiated by the observation that the acidification rate remained constant and the impedance recovered after changing back to the reference medium. Cells in NCTC 135 retained their impedance values but lost vitality. It seems reasonable to suppose that cells in NCTC 135 medium are slowly suffering as indicated by a slow decrease in impedance and highly fluctuating acidification rates. Further experiments for the presented method could be the improvement of the DMEM/Ham’s F12 + ITS medium. With the new method electrical cell-substrate impedance and extracellular acidification responds of the cells can be measured immediately and consequently the quality of new CCM can be quantified.

Alexander, F., Eggert, S. and Wiest, J. (2018) ‘A novel lab-on-a-chip platform for spheroid metabolism monitoring’, Cytotechnology. Springer Netherlands, 70(1), pp. 375–386. doi: 10.1007/s10616-017-0152-x.

Brischwein, M. and Wiest, J. (2019) ‘Microphysiometry’, in Wegener, J. (ed.) Label-Free Monitoring of Cells in vitro. Cham: Springer International Publishing, pp. 163–188. doi: 10.1007/11663_2018_2.

Hartung, T. et al. (2010) ‘First alternative method validated by a retrospective weight-of-evidence approach to replace the Draize eye test for the identification of non-irritant substances for a defined applicability domain.’, Altex, 27(1), pp. 43–51. doi: 10.14573/altex.2010.1.43.

McConnell, H. M. et al. (1992) ‘The cytosensor microphysiometer: Biological applications of silicon technology’, Science, 257(5078), pp. 1906–1912. doi: 10.1126/science.1329199.

Wiest, J. et al. (2016) ‘Data Processing in Cellular Microphysiometry’, IEEE Transactions on Biomedical Engineering, 63(11), pp. 2368–2375. doi: 10.1109/TBME.2016.2533868

Chemically defined cell culture media – a contribution to address the reproducibility crisis in biomedical sciences

Tilo Weber1, Kristina Wagner1, Joachim Wiest2*

11th World Congress on Alternatives and Animal Use in the Life Science, Abstract overview, 2020, 114

1 German Animal Welfare Federation
2 cellasys GmbH

Corresponding author: wiest@cellasys.com


The use of fetal bovine serum (FBS) in cell culture media has different drawbacks. The
harvesting of FBS from bovine fetuses after slaughter of the pregnant parent (dam)
raises ethical and legal concerns. From a pure scientific point of view the use of FBS is
inacceptable since regional differences in type and concentration of ingredients exist
(Baker, 2016, van der Valk et al., 2010). Hence, a non-definable quality of FBS
undermines data reliability and decrease or even prevent experimental reproducibility.
However, the use of chemically defined cell culture media is still scarce.
The introduction of chemically defined cell culture media is a contribution to fight the
reproducibility crisis in the biomedical sciences and an approach to address animal
welfare concerns. Usage of chemically defined medium will eliminate some unknowns in
cell culture experiments. A procedure to develop serum free media was introduced by
van der Valk and colleagues (van der Valk et al., 2010). In the presented work, a detailed
recipe to prepare a defined DMEM / Ham’s F12 + ITS cell culture medium is given. This
medium has proven to work in our laboratory for L929 and Caco-2 cell lines in
combination with a certain plastic ware (Greiner Bio-One, Advanced-TC). To prepare the
chemically defined cell culture medium (DME /F12+ITS) mix 50% DMEM (e.g. Sigma
Aldrich, D5648) and 50% Ham’s F12 (e.g. Sigma Aldrich, N6760), add 14.7 mmol/l NaCl,
20.9 mmol/l NaCHO3 and 5 ml/l ITS (Sigma Aldrich, I3146) (cellasys, 2019). The medium
was developed for cell culture in a 5% CO2 incubator. The presented method was
employed to develop a chemically defined cell-based assay for cytotoxicity
determination according to ISO10993-5 (Wiest, 2017), furnishing a first proof of its
applicability as an alternative to cell culture media containing FBS.

Baker, M. (2016). Reproducibility: Respect your cells!. Nature 537, 433–435.
doi:10.1038/537433a;

cellasys (2019). https://www.cellasys.com/wpcontent/
uploads/2019/10/wwwSOP-G200-005_DME-F12-ITS_medium_preparation_V1_3-
1.pdf
;

van der Valk, J., Brunner, D., De Smet, K. et al. (2010). Optimization of chemically
defined cell culture media – Replacing fetal bovine serum in mammalian in vitro
methods. Toxicology in Vitro 24(4), 1053–1063. doi:10.1016/j.tiv.2010.03.016;

van der Valk, J., Bieback, K., Buta, C. et al. (2018). Fetal Bovine Serum (FBS): Past – Present –
Future. ALTEX 35(1), 99–118. doi:10.14573/altex.1705101;

Wiest, J. (2017). Chemisch definiert – ein zellbasierter Zytotoxizitätsassay ohne fötales Kälberserum. BIOspektrum
23, 61. doi:10.1007/s12268-017-0768-6

Chemically defined formation of spheroids loaded with superparamagnetic iron oxide nanoparticles

J. Wiest1*, E. Stetter2, M. Koch3

11th World Congress on Alternatives and Animal Use in the Life Science, Abstract overview, 2020, 60

1 cellasys GmbH, Kronburg / Germany,
2 Stetter Elektronik, Seeheim-Jugenheim / Germany,
3 Feldkraft Ltd., Copenhagen / Denmark

Corresponding author: J. Wiest, wiest@cellasys.com

To increase physiological relevance and to develop new therapies 3D spheroids are of increasing interest. The addition of superparamagnetic iron oxide nanoparticles (SPIONs) into the spheroid allows for investigation of new therapeutic strategies (Zhang et al., 2014) without the use of animals (Lei and Schaffer, 2013; Whatley et al., 2014; Marx et al., 2016). L929 fibroblasts were maintained in 25 mL Greiner Bio-One AdvancedTC© cell culture flasks in chemically defined DME/F12+ITS cell culture medium. Cells received fresh medium twice a week and were passaged at about 80% confluency once a week. Spheroids were created similar to a previously developed method (Alexander, Eggert and Wiest, 2018). The 20 nm SPIONs beads were obtained from micromod Partikeltechnologie GmbH (Rostock / Germany) and a stock solution with 100 µg/mL was prepared. Spheroids were prepared in a 96 well-plate with cell-repellent surface (Greiner Bio-One GmbH, #650970). Each well was filled with 190 µL DME/F12+ITS containing 10.000 L929. For the SPION loaded spheroids (SPION-LS), 10 µL of magnetic beads stock solution was added, whereas for the non-magnetic control spheroids (NM-CS) 10 µL of cell culture medium was added. Then the 96well plate was centrifuged at 1000 g for 5 min and finally incubated at 37°C with 5% CO2. 100 µL of medium in each well was replace by fresh DME/F12+ITS (preheated to 37°C) daily. Spheroids were used for the experiments on day 5. For manipulation of the spheroids a neodym magnet (length 25 mm, diameter 25 mm) was used in a distance of approximately 30mm. The calculated field force acting on the spheroids was approximately 30mT. To investigate if the SPIONs are incorporated into the spheroids one SPION-LC was transferred to a well with one NM-CS. The movement of the SPION-LC due to the applied magnetic field can be seen at https://youtu.be/ev9bZnKyvGA .

Alexander, F., Eggert, S. and Wiest, J. (2018) ‘A novel lab-on-a-chip platform for spheroid metabolism monitoring’, Cytotechnology. Springer Netherlands, 70(1), pp. 375–386. doi: 10.1007/s10616-017-0152-x.

Lei, Y. and Schaffer, D. V. (2013) ‘A fully defined and scalable 3D culture system for human pluripotent stem cell expansion and differentiation’, Proceedings of the National Academy of Sciences of the United States of America, 110(52). doi: 10.1073/pnas.1309408110.

Marx, U. et al. (2016) ‘Biology-inspired microphysiological system approaches to solve the prediction dilemma of substance testing’, Altex, 33(3), pp. 272–321. doi: 10.145/3/aitex.1603161.

Whatley, B. R. et al. (2014) ‘Magnetic-directed patterning of cell spheroids’, Journal of Biomedical Materials Research – Part A, 102(5), pp. 1537–1547. doi: 10.1002/jbm.a.34797.

Zhang, E. et al. (2014) ‘Dynamic Magnetic Fields Remote-Control Apoptosis via Nanoparticle Rotation’, ACS Nano. American Chemical Society, 8(4), pp. 3192–3201. doi: 10.1021/nn406302j.

5th German Pharm-Tox Summit

Cell line authentication

For biocompatibility assays and the cellasys #8 protocol we use the L929 cell line. As a prerequisition for reliability of data, our cell line was recently analysed by the Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH.

Please find the species identification in our quality management section.

EUSAAT 2019

cellasys, Technische Universität München and MatTek In Vitro Life Science Laboratories present recent updates about our “Tissue-on-a-Chip” at the 22nd European Congress on Alternatives to Animal Testing:

Tissue-on-a-Chip



In this study we demonstrate a microphysiometric system based on IMOLA‑IVD device that will allow real-time measurement of multiple parameters in human small intestine tissue model (EpiIntestinalTM). The parameters are measured non-invasively, while the system provides fresh nutrients and allows programmable repeated dosing of test articles. In the presented set of experiments we have concentrated on trans-epithelial electric resistance (TEER) as this parameter was previously established to reflect an integrity of EpiIntestinal tissue model. The performance of the system was verified and baselines were established by long term incubation of EpiIntestinal tissue in IMOLA-IVD, followed by single application of 2% SDS.

Animal Experimentation: Working Towards a Paradigm Change


Workshop und deutsche Buchpremiere am 14. und 15. Juni in München

Tierversuche zählen zu den umstrittensten Praktiken, in denen wir Tiere nutzen, insbesondere weil den Tieren hier absichtlich Schmerzen, Leiden und Schäden zugefügt werden – mit der Begründung eines möglichen Erkenntnisgewinns für den Menschen. An dieser Rechtfertigung für die Unerlässlichkeit von Tierversuchen hat sich wenig geändert, und das, obwohl nicht nur die ethischen Probleme, sondern auch die wissenschaftlichen Mängel von Tierversuchen mittlerweile offensichtlich und gut dokumentiert sind. Dieses Wissen über die Probleme im Zusammenhang mit Tierversuchen ist allerdings noch nicht weit verbreitet, und es besteht die Gefahr, dass es schlicht ignoriert wird.


Der Flyer findet sich hier.

Cells and tissue as prediction model at EMBC 2019

The combination of classical engineering disciplines and knowledge from cell biology allows the construction of physiologically relevant models to predict processes in the human body in-vitro. In the symposium different aspects of tissue-on-a-chip systems are presented. These include a biopsy-based approach to develop personalized therapies for cancer patients. A bone-on-a-chip that allows the investigation of 3D bone organoids under mechanical load and it’s optimization using in-silico technologies. Further, the necessity of including immune cells into models of osteochondral tissues will be discussed. Examples about applications of dynamic magnetic fields to improve transfection and apply mechanical force inside living cells, a case study about a tissue-on-a-chip system for skin and intestine for applications in toxicology and aspects to employ living cells as biosensors in microphysiometrical systems are on the agenda.

At IEEE EMBC 2019 in Berlin / Germany cellasys co-organizes a symposia on:

Cells and tissue as prediction model for toxicology, drug development and personalized medicine ( organized by J. Wiest and F. Schulze )


M. Brischwein: Development of personalized therapies for cancer with 3D tumor spheroids

Multicellular tumor spheroids are 3D models generated from various cell types, including heterogeneous tissues of solid human tumors. They have proven utility for predictive testing of patient samples to identify the most promising pharmaceutical anti-cancer treatment.


F. Schulze: Mechanical loading of human osteoblasts in a bone-on-a-chip

Organ-on-chip systems are used to recreate the physiology of a certain tissue or organ of interest, thereby enabling more detailed investigations than conventional cell culture allows for. In this project a bone-on-a-chip system is presented that allows for control of oxygen levels and mechanical loading


A. Lang: Modelling the crosstalk between immune cells and bone

Interaction between immune cells and bone metabolism plays a crucial role in the pathogenesis of several disorders affecting the musculoskeletal system. However, current engineering approaches exclude the immune system due to its complexity. Here, we aim to present the importance of modelling the crosstalk between immune cells and bone as exemplified by mimicking the initial phase of fracture healing in vitro.


M. Koch: New magnetic field device for application with laser microscopes

A new digitally controlled field generator is integrated into a laser microscope. Magnetic particles powered non-invasively by the field generator treat cell populations inside a dish above the microscope lens, which can be observed in real time.


J. Wiest: Tissue-on-a-chip

Microphysiometry is a powerful tool to monitor the energy metabolism and changes in morphology of living cells. Until now, the technique was mainly used for monitoring of cells in 2D monolayers. Now, the cellasys group showed that it is possible to monitor the extracellular acidification rate (EAR) and transepithelial electrical resistance (TEER) of 3D skin constructs in an automated assay maintaining an air liquid interface (ALI) with the IMOLA-IVD technology.