- Climate, Environment & Health
WITH 3D AGAINST ANIMAL TESTING
It is well known that liver cells have to be able to withstand a lot - in the human body; they ensure a functioning metabolism and break down toxins, among other things. Liver diseases usually require intensive treatment and are often fatal if no suitable donor organ is available. Despite their enormous capacity, however, liver cells are sensitive when it comes to testing new drugs or treatments on them. If they are cultivated in vitro for analysis purposes, as is customary in pharmaceutical research, they lose almost all their function after around five days. This is a particular problem for long-term toxicological stress tests. The KIT spin-off 300MICRONS has found a new way to breathe artificial life into cells for longer. The technology makes it possible to cultivate cells three-dimensionally in such a way that their organotypic properties can be preserved over significantly longer periods.
"We are developing film-based 3D cell culture systems that allow us to provide cells with an external support scaffold so that cells can arrange themselves in a more natural way in the so-called microwells, or microcavities, of the film. Liver cells, for example, still maintain at least 50 percent of their function over two months," says Professor Eric Gottwald, one of the three founders of 300MICRONS. The system works for many cells studied so far, including adult or induced pluripotent stem cells, which require the highest physiological environment possible outside of the body. This offers a highly interesting prospect for pharmaceutical companies, which have come under increasing pressure in recent years due to controversial animal testing and the growing number of substances to be tested. After all, when cells cannot be tested in standard two-dimensional procedures, new drugs are tested on mice and rats. A 3D assay can eliminate the need for these animal tests in the preclinical phase because the cell culture system effectively replaces the cell's organ of origin. "We provide cells with an organotypic environment and can still meet pharmaceutical and biotechnology requirements. Our products are developed for standard academic and industrial formats and are particularly suitable for high-throughput or high-content screening," says Eric Gottwald.
The fact that two-dimensional analyses are problematic is know since decades. Nevertheless, it is only since the early 2000s that the industry has been focusing on alternative 3D tests. The first scientific experiments were conducted in the 1960s. Eric Gottwald started to work on 3D cell cultures at today's Campus North of KIT in 1996. One goal of his work was to develop a biohybrid liver based on the microcavity arrays developed at KIT. When initial systems were developed to the point where they could be tested in animal experiments, EU prohibited the use of porcine hepatocytes for human therapeutic purposes, the gold standard of cell material for bioreactors for human therapeutic projects at the time.
The bioreactor system was then developed into a stem cell platform capable of preserving blood stem cells in their stem cell properties. These are used, among other things, in the treatment of leukemia. Leukemia patients often suffer from a severely weakened immune system after chemotherapy and need stem cells to rebuild it. However, suitable stem cell donors are not always available. "Our alternative solution was to remove stem cells from the patient before therapy, cultivate them in our cell culture system, and then transplant them again to accelerate recovery. In contrast to the transplantation of foreign stem cells, there is no risk of "rejection". The results of this development look very promising so far and a patent has already been filed.”
Since 2015, Gottwald, Giselbrecht and Truckenmueller have been joint founders of the company 300MICRONS, in which KIT and a private investor hold shares. The young company was completely funded by the Helmholtz Association of German Research Centers with the "Helmholtz Enterprise" program. The foil chips can be integrated into standard industrial microtiter plates. The design and geometry of the cavities in the foils can be freely selected and are thus suitable for many different applications. To further adapt the in-vitro conditions of the cells to the natural environment, pumps can be connected to simulate e.g. the blood flow in the human body during the tests.
In order to be able to cultivate the stem cells, Gottwald, a biologist, used the experience he had gained with his team to develop the biohybrid liver, because stem cells also tolerate an artificial environment. In the course of their research at the time, his colleagues Stefan Giselbrecht and Roman Truckenmueller developed a microthermoformed cell culture carrier in the form of a chip with precisely defined microcavities that can be made from films of a wide variety of polymers. Cells can be filled into these wells - for example, a mixture of bone marrow and stem cells - as if into a small pot, instead of on a flat surface of a Petri dish as was previously the case. It seemed obvious to be able to offer this advantage for many other pharmaceutical and biological applications as well, recalls Eric Gottwald: "That's how we came up with the idea for the KIT spin-off. However, we took a few more years, during which market interest in such solutions continued to grow and we were able to develop our system to near product maturity."
The machines and molding tools, needed to produce the arrays, were all developed by the KIT scientists themselves. In the almost 20 years since the start of research, KIT has registered more than 40 industrial property rights on them, which today secure the know-how of 300MICRONS. An important aspect, as the founders emphasize: "3D cell culture systems will gain importance in industry and we are sure that we offer a technologically very attractive product portfolio".
The scientists and founders have not quite reached their goal yet. In the coming years, the complete manufacturing process for the systems is to be fully automated, production volumes are to increase significantly and fields of application beyond pharmaceuticals are to be developed. For example, the 300MICRONS microfoils could also serve as packaging for the company's own product, explains Eric Gottwald: "We dream of soon being able to ship ready-made analysis kits. Finished microtiter plates, equipped with the cells we offer, securely packaged in our own film - a complete package".