Stem cell biologist Sue Chun Chang and his team at the Duke-National University of Singapore School of Medicine and the University of Wisconsin-Madison are developing techniques to study communication between brain cells and model disease pathology.
Duke-NUS Medical School
The human brain is bustling with intricate neural highways that send signals between neurons. Understanding these networks is essential to unraveling brain health and disease, but existing models have met with mixed success. Su ChunZhangcollaborators, stem cell biologists from the Duke-National University of Singapore School of Medicine and the University of Wisconsin-Madison, who will design a platform to reliably model functional neural tissue.
Zhang and his team developed a bioink composed of proteins and gel polymers to 3D print brain tissue. Investigation resultpublished in Cell Stem CellIt offers researchers a promising tool for designing and studying customized brains.1 “Just like we have all the ingredients needed to cook a dish, we have developed the technology to induce human stem cells into many types of neural cells — now we just need to put them all together,” Zhang explained.
3D bioprinting allows researchers to choose cell types and spatial distribution to replicate brain tissue, whereas traditional 3D bioprinting involves stacking cells layer by layer. VerticallyHowever, these structures often fail to support proper cellular connections.2 Zhang’s team created the Goldilocks bioink using fibrin hydrogel, which provides optimal stiffness for the structural integrity and survival of cells. They layered neurons and astrocytes horizontally in a pattern resembling the cerebral cortex and striatum, aiming to create functional neural circuits.
Although Zhang expected random neural connections from artificial printing, the tissue behaved exactly like in the brain: Electrophysiological recordings and calcium imaging showed consistent neural communication within and between brain regions.
Massimiliano Caiazzo“It would be interesting to create in vitro synaptic circuits that can be tuned to model diseases,” said a neurobiologist at Utrecht University who was not involved in the study.
“Because we have essentially control over the organization of the tissue, we can artificially design models that may or may not exist in the brain and observe how these cells talk to each other,” Zhang noted.
