Stem cell research: Laboratory in a bag
Human stem cells are considered a major new hope in medicine. It is expected that they will make it possible to treat a wide range of ailments such as neurodegenerative diseases. With LabBag, Fraunhofer researchers have developed an all-in-one system in the form of a transparent bag.
LabBag provides a cheap, fast and sterile way for scientists to grow, differentiate and freeze stem cells. As part of the LabBag project, the Fraunhofer Institute for Biomedical Engineering IBMT, the Fraunhofer Institute for Surface Engineering and Thin Films IST, and the Fraunhofer Institute for Process Engineering and Packaging IVV have pooled their expertise to develop a miniature laboratory in the form of a plastic bag.
Inside this bag, human induced pluripotent stem cells – in other words, artificially produced stem cells – are able both to grow and to form 3D aggregates in a sterile environment. These cells can be used by the pharmaceutical industry as patient- or disease-specific test systems for drug development and research into active ingredients.
Until now, stem cell aggregates have been generated by using pipette feeder robots (which are expensive to purchase and maintain) or by means of manual pipetting (which is labor- and time-intensive). Manual pipetting in petri dishes requires a lot of practice, and there is also the risk of contamination.
The “laboratory in a bag” developed by Fraunhofer researchers aims to reduce the costs of labor and materials while also significantly increasing cell yield and process reliability. Simply by shaking the transparent bag, it takes just a few seconds to produce several hundred hanging droplets of nutrient solution, virtually automatically. The droplets function as mini-bioreactors in which cell aggregates are able to form.
First of all, the nutrient solution containing the stem cells is poured into the bag. The bag is rotated once and then returned to its initial position. During this process, the droplets remain suspended on round hydrophilic spots. The cells sink to the bottom of the droplets, where they bind together and fuse to form a defined 3D aggregate. “We have coated the polymer film of the bag with two different coatings,” explains Dr. Michael Thomas, project manager and scientist at Fraunhofer IST, whose team is responsible for the coating of the polymer film. “A hydrophobic, water-repellent base layer ensures that the nutrient solution containing proteins flows over the surface and doesn’t stick to it. However, the second layer consists of 150 hydrophilic round spots, each with a diameter of 5 millimeters.”
A prototype of this patent-pending disposable bag will be presented November 13-16 at the joint Fraunhofer booth at the MEDICA trade fair in Düsseldorf (Hall 10, Booth G05/H04). The mini GMP laboratory offers the pharmaceutical industry – and also smaller laboratories with no clean room technology – the opportunity to grow high-quality cell models for drug research without incurring high investment costs.