Microsystems for in-vitro Cell Models

Animation of cell seeding and assembly of the organ-on-chip system.

In vitro cell models are used as disease models in drug screenings and toxicity tests and in basic research to develop and organize various tissue types. Based on our expertise in cell biology, material sciences and coatings, as well as microsensors and microfluidics (design, manufacturing and integration), we develop microreactors for short- and long-term studies on cell tissue. These reactors ensure a cell culture under controlled physiological conditions. By integrating microsensors into these systems, we can for the first time extend continuous real-time measurements of cell vitality or metabolites to up to one month. Compared to conventional endpoint measurements, this approach provides a much more in-depth and direct access to the understanding of drug mechanisms. In addition to the design and development of microbioreactors, we realize in vitro studies to evaluate the liver toxicity of chemical substances.

Animation of cell seeding and assembly of the organ-on-chip system.
© Fraunhofer IZI-BB
Animation of cell seeding and assembly of the organ-on-chip system.

Service offer

  • Design and manufacturing of microfluidic systems concerning cell-specific requirements
  • Automation
  • Sensor integration (oxygen, pH value, glucose)
  • Toxicity screening of substances (contract measurements)
Microsystems for in-vitro cell models
© Fraunhofer IZI-BB
(left) Cells are embedded together with the optical sensor particles in a 3D matrix and supplied via a channel above. (middle) Illustration of a continuous flow channel with embedded cavities, which are used to hold the cells and optical sensors. (right) The organ-on-chip system is integrated into an automated environment. Thus, 12 different conditions can be tested in parallel.

HepatoTox: Microfluidic bioreactors for in vitro toxicity measurements (Liver-on-a-Chip)

Microfluidic bioreactors for in-vitro toxicity measurements (Liver-on-a-Chip)
© Fraunhofer IZI-BB
Microfluidic bioreactors for in-vitro toxicity measurements (Liver-on-a-Chip)

We are developing in vitro test methods for the evaluation of long-term toxicity of active substances in order to replace animal experiments in the medium term. The maintenance of the vitality and functional properties of cell systems over sufficiently long periods of time requires continuous monitoring of cultivation conditions. The concentrations of glucose, oxygen and the pH-value of the cell culture medium in the bioreactor are the most important parameters. The continuous measurement of these parameters not only allows a rigorous quality control, but also provides the input signals for an automated operation of the microreactor. An essential part of the activities of the research group is dedicated to the development of sensor technology and its integration into the microreactors. The challenges arise from the miniaturization and the resulting small sample volumes as well as the requirements for long-term stability.

ParOptiSens: Development of particle-based optical sensors for real-time analysis of metabolic processes for in vitro test systems

© Fraunhofer IZI-BB

Here, the focus is on the development of microsensor particles for real-time monitoring of the viability of cells cultured in artificial environments (in vitro). This approach allows rapid and detailed assessment of the effect of drugs or toxic substances on cell samples in physiological environment. The integration of sensors into microphysiological systems is particularly relevant in two areas:

  1. Patient specific therapies: Advances in biomedicine already allow for the individual examination of patient-specific tissue samples in order to identify suitable drugs, minimize side effects and adjust the dosage for therapies.
  2. Toxicity measurements: In the future, alternative methods to animal experiments, i.e. in vitro test systems, will be used to evaluate pharmaceuticals, chemicals and cosmetics with regard to their toxicity and biocompatibility and to investigate new therapies in basic research. Besides the ethical motivation, the high time and cost factor of animal models is the driving force for the development and establishment of such cell tests.

The measurement system to be developed here will allow the optical analysis of the metabolic indicators oxygen, glucose and pH-value within the cell tissue in real time.

FormCell: actuators made of shape memory polymers as functional components of microbioreactors for cell cultures

Together with the Fraunhofer IAP we develop novel reservoirs for the release of active ingredients and signal molecules in microreactors for the control and manipulation of cell cultures with high temporal and spatial resolution. To achieve a targeted biochemical control of cell behavior, central functional units consisting of externally addressable control elements based on shape memory polymers (FGPs) are integrated into microfluidic environments and combined with real-time measurements of cell vitality.

Methods

  • Development and production of functional coatings for applications in the field of cell cultivation and tissue engineering: Coatings made of thermoresponsive polymers for monitoring cell adhesion on cell culture substrates, polyelectrolyte layers (layer-by-layer (LbL) application) and reservoirs for biomolecules for controlling adherent cells, layers (self-assembled monolayers (SAM)) made of polymers, and biomolecules for improving the biocompatibility of synthetic surfaces
  • Design and development of micro-bioreactors for the long-term cultivation of complex cell models
  • Integration of microsensors into microfluidic systems for real-time analysis of key variables of cell media (e.g. oxygen, pH, glucose, lactate)
  • Development of in-vitro test systems for the assessment of the toxicity of chemicals, pharmaceutical agents and ingredients used in cosmetics
  • Storage and cultivation of eukaryotic cells at S1 biosafety level (mammalian cells, insect cells, primary cells, cell lines)
     

Equipment

  • Transmitted and reflected light microscopy with bright field, phase contrast, fluorescence, polarization and total reflection modes (TIRFM), super-resolution structured illumination microscopy (SIM), each equipped with computer-controlled and temperature-controlled specimen stages and cell culture chambers
  • Confocal scanning laser microscope with 3D image processing
  • Fully automated fluorescence microscope for producing images of living cells under physiological conditions (time-lapse microscopy) (Olympus CellR)
  • TIRF microscopy (Olympus)
  • Laser tweezers with laser microdissection (Palm/Zeiss)
  • Variable microfluidics setup
  • Microcontact printer (GeSiM)
  • Contact angle measuring device
  • Flow cytometer (Becton D.)
  • Micromanipulation, microinjection, microdissection (Eppendorf)
  • Cell characterization: Cell staining techniques (e.g. immunofluorescence), transfection with fluorescent fusion proteins, live staining, proliferation tests

Publications

  • Gehre C, Flechner M, Kammerer S, Küpper J-H, Coleman C D, Püschel G P, Uhlig K, Duschl C. Real time monitoring of oxygen uptake of hepatocytes in a microreactor using optical microsensors. Sci Rep (2020) 10, 13700.
  • Bavli D, Prill P, Ezra E, Levy G, Cohen M, Vinken M, Vanfleteren J, Jaeger MS, Nahmias Y. Real-time monitoring of metabolic function in liver-on-chip microdevices tracks the dynamics of mitochondrial dysfunction. PNAS (2016) 113, S. E2231-E2240.
  • Prill S, Bavli D, Jaeger MS, Schmälzlin E, Levy G, Schwarz M, Duschl C, Ezra E, Nahmias Y. A Real-Time Monitoring of Oxygen Uptake in Hepatic Microwell Bioreactor Reveals CYP450-Independent Direct Mitochondrial Toxicity of Acetaminophen multilayers. Archives of Toxicology, 90 (2016) 1181-1191. DOI dx.doi.org/10.1007/s00204-015-1537-2
  • Prokopovic VZ, Vikulina AS, Sustr D, Duschl C, Volodkin D. Towards an artificial extracellular matrix: Biopolymer based multilayers coated with gold nanoparticles. Assessment of biodegradation, molecular transport, and protein mobility. ACS Applied Materials and Interfaces 8 (2016) S. 24345-24349.
  • Prill S, Jaeger, MS, Duschl C. Long-term microfluidic glucose and lactate monitoring in hepatic cell culture. Biomicrofluidics. (2014) 8, 034102.
  • Renner A, Jaeger MS, Lankenau A, Duschl C. Position-dependent chemotactic response of slowly migrating cells in sigmoidal concentration profiles. Appl Phys A. (2013), 112(3), 637-645.
  • Madaboosi N, Uhlig K, Schmidt S, Jaeger MS, Möhwald H, Duschl C, Volodkin D. Microfluidics meets soft layer-by-layer films: selective cell growth in 3D polymer architectures. Lab Chip. (2012), 12, S. 1434-1436.
  • Felten M, Staroske W, Jaeger MS, Schwille P, Duschl C. Accumulation and filtering of nanoparticles in microchannels using electrohydrodynamically induced vortical flows. Electrophoresis. (2008), 29, 2987-2996.
  • Jaeger MS, Uhlig K, Clausen-Schaumann H, Duschl C. The structure and functionality of contractile forisome protein aggregates. Biomaterials. (2008), 29, 247–256.
  • Uhlig K, Jaeger MS, Lisdat F, Duschl C. A biohybrid microfluidic valve based on forisome protein complexes. J MEMS. (2008), 17(6), 1322-1328
  • Felten M, Geggier P, Jaeger M, Duschl C. Controlling electrohydrodynamic pumping in microchannels through defined temperature fields. Phys Fluids. (2006), 18, 051707.
  • Gast FU, Dittrich PS, Schwille P, Weigel M, Mertig M, Opitz J, Queitsch U, Diez S, Lincoln B, Wottawah F, Schinkinger S, Guck J, Käs J, Smolinski J, Salchert K, Werner C, Duschl C, Jäger M, Uhlig K, Geggier P, Howitz S. The microscopy cell (MicCell), a versatile modular flowthrough system for cell biology, biomaterial research, and nanotechnology. Microfluid Nanofluid. (2006), 2, 21–36.

Patents

  • Jaeger M, Prill S, Nahmias Y, Bavli D. Method and system for continous monitoring of toxicity. EP15160661.3 / US 2015/0268224 A1

  • GeSiM mbH, Großerkmannsdorf
  • Mikrofluidik ChipShop, Jena
  • BST Bio Sensor Technology GmbH
  • University of Jerusalem, Israel
  • Ecole Polytechnique Federal Suisse, Lausanne, Schweiz
  • Centre Suisse dElectronique et Microtechnique Neuchâtel, Schweiz
  • Universität Bielefeld
  • Nottingham Trent University
  • Brandenburgische Technische Universität Cottbus-Senftenberg
  • Universität Potsdam
  • Surflay Nanotec GmbH