Microfluidic flow chamber for cell separation and cultivation

Immunotherapy using dendritic cells is an experimental procedure that is currently investigated in treatment of cancer. In the procedure, monocytes are taken from the blood and cultivated in the presence of biochemical substances to proliferate into dendritic cells. Dendritic cells have the ability to activate the bodies immunoresponsive system, so by delivering dendritic cells encoded towards cancer into the body, the dendritic cells can start an immunoreactive response towards the cancer cells.

The procedure as it is currently performed is labor intensive and not easy to standardize. In an innovation consortium called CEMIK we are working with the different parts of the procedure and trying to perform them in ways that are easy to standardize and automate. We have been working in microfluidic systems with separation of adherent cells (monocytes) from non-adherent cells (lymphocytes), culture of the adherent cells, and the release of them after about a week of incubation.

In our lab we can fabricate fast prototypes. So within a short time period many different chamber designs and surfaces have been tested. The chamber heights can easily be varied from 50 µm to several mm’s, and the chamber design can be chosen as desired. We also have many different types of easy-to-use interconnectors.

Figure 1 shows a system with 140 µm high chamber and connectors for 1/16 inch Teflon tubing.

Figure 2 and 3 show phase contrast and fluorescence micrographs from experiments with different surfaces.

Figure 4 shows a custom made mini incubator which enables us to observe the systems while controlling the temperature.

Figure 5 shows another custom made mini incubator with room for more or larger systems, and with control of the atmosphere and temperature via a Peltier element.

Figure 1: Cell chamber system with arc treated polystyrene surface filled with a blue colored liquid. The chamber is 10 mm wide and 140 µm high.

Figure 2. Micrographs from experiment in a system with an arc treated polystyrene surface. (a) After incubation for 1 hour. (b), (c) Micgraphs after separation using vaverage=24 mm/s, and fluorescent staining. (b) Phase contrast and (c) fluorescence micrograph of the same area.

Figure 3. Phase contrast micrographs from an experiment in a system with thermal responsive polymer surface. (a) At the start of the incubation. (b) After 45 min. incubation. (c) after separation with v_average=24 mm/s. (e) After lowering of temperature to ≈ 28ºC and flushing back and forth with v_average=24 mm/s.

Figure 4. Miniaturized incubation chamber placed on top of a microscope

Figure 5. Parallel miniaturized incubation chambers placed on top of a microscope.