Gas Supply through Agarose Walls in Cell Culturing Microchips

Abstract:

We present a novel structure to supply gases to microchambers in microfluidic chips. An exemplary application is the continuous feeding of oxygen and CO₂ for on-chip cell cultivation of mammalian cells. In our device, the surrounding air diffuses into the culture medium inside the chip through a porous wall of agarose hydrogel resulting in an easy and robust design. One common method is the usage of gas permeable PDMS chips. However, liquid medium in which the cells grow is absorbed by PDMS causing unknown concentrations and memory effects. Another possibility is a complex setup where medium with already dissolved gas is pumped constantly through the chip. We designed and realized a silicon and borosilicate glass chip containing a gas permeable wall of agarose preventing leakage of medium. In order to precisely position the walls in the chip, we made use of surficial phaseguides (50nm high). The blue-bottle-experiment makes the effective dissipation of oxygen visible when the colorless leucomethylen-blue reacts to methylene-blue. Successful results were achieved when applying 0.5 g/l methylene blue, 10 g/l glucose and a pH of 12.6 set by a buffer solution. As a result a continuous color gradient through the chip was obtained, which reflects the oxygen gradient and confirms the oxygen diffusion.

• Periodical: Advances in Science and Technology (Volume 100)
• Pages: 115-119
• DOI: https://doi.org/10.4028/www.scientific.net/AST.100.115
• Online since: October 2016
• Authors: Frank Bunge*, Sander van den Driesche, Michael J. Vellekoop
• Keywords: Diffusion, Gas, Hydrogel, Microfluidic, Oxygen

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