Researchers Elevate Brain Research with 3D Printing Success

Scientists at the University of Wisconsin–Madison have created the first brain tissue that can be printed in three dimensions and can grow and function normally. This accomplishment has significant ramifications for researchers studying the brain and developing therapies for a variety of neurological and neurodevelopmental conditions, including Parkinson’s and Alzheimer’s disease. 

According to Su-Chun Zhang, a professor of neuroscience and neurology at the Waisman Center at the University of Wisconsin–Madison, “this could be a hugely powerful model to help us understand how brain cells and parts of the brain communicate in humans.” “It could change the way we look at stem cell biology, neuroscience, and the pathogenesis of many neurological and psychiatric disorders.” 

Zhang and Yuanwei Yan, a scientist in Zhang’s group, claim that the success of earlier attempts to print brain tissue has been limited by printing techniques. The team behind the novel 3D printing technique publishes a method description in the journal Cell Stem Cell. 

The researchers used a horizontal technique for 3D printing as opposed to the conventional method of stacking layers vertically. They placed neurons, which were derived from induced pluripotent stem cells, in a more pliable “bio-ink” gel than those used in earlier experiments. 

“The tissue still has enough structure to hold together but it is soft enough to allow the neurons to grow into each other and start talking to each other,” Zhang explains. 

The cells are arranged in a row like how pencils are on a tabletop. 

“Our tissue stays relatively thin, and this makes it easy for the neurons to get enough oxygen and enough nutrients from the growth media,” Yan explains. The cells can communicate with one another, as seen by the data, which speaks for themselves.

The printed cells establish networks akin to human brains by reaching through the medium to form connections both within and across printed layers. Neurotransmitters allow neurons to interact, communicate, send messages, and even create correct networks with support cells added to the printed tissue. 

“We printed the cerebral cortex and the striatum and what we found was quite striking,” Zhang explains. “Even when we printed different cells belonging to different parts of the brain, they were still able to talk to each other in a very special and specific way.” 

The printing method provides a level of precision—control over the kinds and configuration of cells—that is absent from brain organoids, which are microscopic organs utilized in brain research. Organoids develop with less control and organization. 

The ability to create almost any kind of neuron at any time makes our lab unique. After that, we can put them together whenever we want and in any way we like, according to Zhang. “We can have a defined system to look at how our human brain network functions since we can print the tissue by design. Because we can print exactly what we want, we can examine how nerve cells communicate with one another in extremely specific ways under particular circumstances.” 

Journal Reference  

Yuanwei Yan et al, 3D bioprinting of human neural tissues with functional connectivity, Cell Stem Cell (2024). DOI: 10.1016/j.stem.2023.12.009.