Liver_Lab SlideReactor

Most bioartificial liver support systems are based on hollow fiber capillaries within modified dialysis cartridges or more sophisticated bioreactor constructions. Due to their design microscopic follow-up of re-organization and growth of tissue between the hollow fibers is not possible.


The SlideReactor is a simple hollow fiber based bioreactor construction suitable for light microscopy and time-lapse video observation. The SlideReactor offers a cell compartment separated from a medium inflow and outflow compartment. Cell compartment access ports enable easy filling of the cell compartment with cell suspension, as well as fixation of the tissue. For more complex procedures or full access to all the cells, the bioreactor can be opened easily by cutting the silicone seal with a scalpel. Due to its simple design and the utilization of standard materials, it could serve as a suitable, cost-efficient tool to evaluate the behavior of cells cultured between hollow fiber capillaries. The paper describes the production process: similar to open source projects in software engineering, we would like to propose the concept as an open platform to anyone interested in hollow fiber based cell culture.

For more detailed information please refer to the following publications (Artificial Organs 2005, 29: 264-267, Tissue Engineering 2007, 13: 187-196).

The SlideReactor is based on commercially available hollow fiber capillaries (e.g. Micro-PES, Membrana GmbH, Wuppertal, Germany), microscopy slides, silicone tubes and silicone for assembling the parts. In order to enable optimal cell adhesion, one slide consists of adhesive cell culture plastic ware. Plain glass microscope slides that disable cell adhesion are used for the top, in order to provide clear vision (Menzel Slides, Menzel, Braunschweig, Germany). Two short and two longer silicone tubes are embedded into the silicone seal, enabling later access to the framed areas. LuerLock-to-tube connectors are attached to the endings of the tubes and the system is sterilized using gamma sterilisation.

Figure 2: SlideReactor operation and observation system

Figure 1: First the lower slide (1) is framed with silicone (2) and silicone tubes are embedded. To form a cell compartment additional silicone beads (3) are applied to the lateral portions of the slide (A).
The hollow fibers (4) are fixed to these silicone beads and sealed in (B). The second slide (5) is attached (C). The medium inflow chamber (7), the hollow fiber capillaries and the medium outflow chamber (8) are perfused via the longer tubes (9, 10). The cell compartment (6) is accessible via the short tubes (11).
Clip: SlideReactor
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The perfusion system is situated in a heating unit and comprises the SlideReactor, a medium reservoir with probe heads for the continuous determination of pH-, O2 and temperature levels, a circulation pump and a silicone tube oxygenator (figure 2). During cell culture, oxygenated medium is provided to the cells via the medium inlet tube, through the hollow fiber capillaries, and is then removed from the system via the medium outlet port.

For evaluation the SlideReactor was charged with primary human liver cells obtained after partial liver resection and different cell lines (HuH7, C3A and WiDr). During cell culture the cells are analyzed by time-lapse video microscopy. After termination of the culture and a first evaluation by phase contrast microscopy the cells are fixed with PFA, stained with fluorescence dyes (phalloidin, CK18 and DAPI, figure 3) and analyzed via immunofluorescence microscopy. As control, cells were cultured in standard monolayer techniques.

Figure 3: Primary human liver cells at culture day 5: native in the SlideReactor (a), and monolayer control culture (b). Stained with DAPI, phalloidin and CK18 after culture in a SlideReactor

The first experiments showed the feasibility of this concept:The SlideReactor’s cell compartment is completely visible and – due to the use of optical quality glass – ideal for video time-lapse microscopic observation of the behaviour of different cell types cultured between hollow fiber capillaries. Cell divisions as well as movement and growth of the cells can be recorded. The morphology of the cells as well as the growth of the tissue was comparable to the controls. The cells were viable, actin filaments and nuclei showed no abnormalities compared to the control cultures.

The SlideReactor may serve as a simple tool to evaluate the cell-to-cell and cell-to-hollow fiber interaction. The device enables the characterization of cell behavior under controlled conditions and the analysis of the influence of medium supplements on the cell viability and tissue integrity. It may be useful for the comparison of different types of hollow fibers, e.g. for future use in bioreactor-based extracorporeal liver assist devices.

- More on the proof of concept -