Researchers have, for the first time, used stem cells to build structures that resemble three-dimensional brain-like tissue, and the result could be of great interest to the pharmaceutical industry.
The team, reporting in Nature, grew the mini brains, which they termed cerebral organoids, by culturing established embryonic stem cell lines and induced pluripotent stem (iPS) cells under exquisite control in the lab. After developing the cells on a synthetic gel and then placing them in a spinning bioreactor, the cells formed discrete brain regions that could interact with one another, eventually resembling the brain of a 9 week foetus.
“We modified an established approach to generate so-called neuroectoderm, a cell layer from which the nervous system derives," explained Juergen Knoblich, a developmental biologist at the Institute of Molecular Biotechnology (IMBA) in Vienna. "Fragments of this tissue were then maintained in a 3D-culture and embedded in droplets of a specific gel that provided a scaffold for complex tissue growth. In order to enhance nutrient absorption, we later transferred the gel droplets to a spinning bioreactor. Within three to four weeks defined brain regions were formed.”
The growth of the brain tissue was limited, probably by a lack of circulation system. However, the team were still able to use the mini brains as a model for microcephaly, a condition that causes stunted brain growth. iPS cells derived from a human with microcephaly formed smaller clumps of brain tissue than stem cells derived from a healthy human, and the researchers used the model to demonstrate that premature neuronal differentiation was responsible for the effect.
The tiny stem cell-derived brains could therefore have the potential to serve as biological tools, helping researchers uncover the causes of genetic brain disorders and test the effects of new drugs.
To learn more about research and development in the stem cell industry, attend the Stem Cells USA & Regenerative Medicine Congress.