Cell Technology

Core Competencies

  • Software for image-based cell analyses of individual images and time series
  • Reproduction of adherent growing cells in the bioreactor
  • Production of therapeutic cell formulations in the bioreactor
  • Development of tools associated with cell culture
  • Optimization of cell culturing
  • Analysis of new materials for cell culture and cell transplantation

Development of tools and software for image-based cytometry and innovative reactor principles for adherent growing cells 

The Cell Technology workgroup is concerned with three subjects: The development of devices and software for image-based cytometry; the development of bioreactors and new reactor principles for adherent growing cells; and finally with the optimization and development of devices for fast cell culturing from biopsies and investigating the transition of tissue to cell culture. In general terms, the workgroup develops innovative tools and devices for cell culture, cell handling and cell logistics. The workgroup thus operates in the highly exciting border area shared by cell biology, process engineering, computer science, materials science and laboratory tool building. The special competence of the Cell Technology workgroup lies in bringing together these individual disciplines.

,The workgroup has made decisive progress in image-based cytometry in recent years. Image-based cytometry is the quantitative analysis of cell cultures by means of a software-based evaluation of microscopic cell images and image sequences. As early as 2011, the Cell Technology workgroup managed to develop a process able to detect possible errors in tracking individual cells systematically, thus increasing cell tracking reliability to the point that it is equivalent to manual cell tracking by specialists. This breakthrough could have enormous importance for future cell cultures. It is now possible to track what is going on in the cell culture dish fully automatically and to perform a quantitative analysis of cells in real time. Both static parameters (cell shape, size and number) and dynamic parameters (movement analysis, cell divisions) are determined automatically and with high statistical relevance.

Among the cytometric analytical processes that the workgroup has developed is the recent mitosis detection (which works independently from cell detection, see project example). Mitoses or cell divisions are the actual starting and final stages in a cell’s life cycle. Each cell comes to life as a daughter and disappears by forming daughter cells itself. For this reason, mitoses are the most important events in a cell culture and their detection is of eminent importance in cytometry. To perform this work, the EMB developed various algorithms that allow very precise detection of mitotic events. They are used to determine the distribution of cell cycle times in a cell culture. These parameters, although indispensable for describing and understanding complex cell cultures, are almost impossible to ascertain with conventional methods.

Last year, improvements were made in isolating adult stem cells from glandular tissue too. The yield from the isolation was multiplied by optimizing the procedures, process parameters and enzymes used. It is also possible to fully dissociate tissue in vital individual cells, which is a prerequisite for cell population cleaning or fractioning.

Finally, last year the workgroup drove new developments in the area of bioreactors for adherent growing cells. In particular, a novel method for growing cells in bioreactors on microcarriers or hollow fibers is now being implemented. Since most adherent cells generally proliferate only within a restricted density range of approx. 500-50,000 cells/cm2, the achievable proliferation rates – irrespective of method and absolute growth surface – are restricted to about 102 to a maximum of 103. Compared with this, our new methodology allows a cyclically controlled process, in which each cycle yields about ten times the cell quantity. This makes it possible to have expansion factors beyond 104. The principle here is based on the encapsulation of cells in a hydrogel so they can grow in it. Once the capsule is filled with cells, the capsule material can be dissolved and the cell suspension is available for the next encapsulation cycle.

This process offers many advantages: On the one hand, the inoculation/cell harvesting steps are fully dispensed with and are replaced by the encapsulation and capsule-dissolving processes. Thereafter, the reactor can already be operated at its final size, even with small starting cell numbers, and the number of intermediate steps can be drastically reduced. Furthermore, the cells are mechanically protected inside the capsule. Apart from higher survival rates owing to the protection from shear and impact forces, higher flow speeds and volumetric flow rates are also achieved. Finally, the cells grow in a threedimensional environment that allows them to proliferate while maintaining their biological function and identity. This is especially indispensable for stem cell proliferation.            

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RESEARCH PROJECTS

Analysis of complex cell cultures with time-lapse microscopy / cell-based therapies

Software developed at the EMB allows automated tracking of individual cells and the description of cell populations with unheard-of precision. Thus, cell cultures can be characterized non-invasively “just by looking at them” and significant biological parameters can be derived from image series. These biological parameters can say something about the distribution of cell shapes, internal cell movements and migration behavior, as well as about division behavior, the death rate and links between these and other traits. Cell tracking and time lapse experiments, together with the subsequent complex evaluations, can be commissioned from the EMB.

Characterization of novel scaffolds for 3-D cell culture

To control three-dimensional cell growth, various geometric arrangements of materials compatible with cell cultures are tested by systematically varying both the shape and size of carriers. The chemical composition and elasticity of substrates can be selectively changed as parameters of a suitable substrate, along with surface roughness and pore size distribution. Newer activities deal with the encapsulation of cells in gel mixtures containing polypeptides. The Cell Technology workgroup has established precise methods for the quantitative analysis of cell events (precise cell numbers in 3D aggregates; metabolic activity).

Development of cell culture disposables

Disposables are developed from the specific requirements imposed by practice and in collaboration with other EMB workgroups. For example, self-adhering chambers for layered slides are being developed with the Plastic Competence Center of the Lübeck University of Applied Sciences. With their help, it has been possible to quickly and economically research the suitability of novel cell culture surfaces. Furthermore, new substrates for the free-standing freezing of thin tissue sections were developed. Other new developments deal with disposables for the flow culture and optical disposables.

Cryopreservation of cell-based/biologized materials

We establish and optimize processes for tissue and cell cryopreservation. By order, we draw up protocols for preserving biological samples that consider the specific customer’s needs and ensure the highest possible quality of the samples. In particular, the Cell Technology workgroup specializes in the cryopreservation of biologized/cellularized materials – among them cell gels, cell-covered foils and matrices/scaffolds (up to a thickness of about 0.5 mm) and foams containing cells.

Surface analysis for cell culture and cell transplantation

The Cell Technology workgroup has a standardized repertoire of methods to assess the suitability of new materials for cell culture. Among the cell parameters that can be collected routinely and in high throughput are vitality, proliferation, metabolic activity (glucose consumption, lactate production, acidulation power, oxygen consumption), adhesion speed, adhesion force and differentiation potential (FACS, immuno-cytochemistry, RT-PCR). Most of these parameters are collected with the help of automatic or semi- automatic analytical systems. Various combinations of cells or materials can be screened at the same time and optimized for certain applications (cell mass production, clinical use, etc.). The Cell Technology workgroup will gladly perform contract work.

Time-lapse service with fluorescent reporter systems

Our time-lapse microscopes are also available to industrial partners and academic cooperation partners, who can benefit both from our long experience and the possibilities offered by subsequent computer-aided analysis.

Publications