3D-Printing Functional Human Brain Tissue

A team of University of Wisconsin-Madison scientists has developed the first 3D-printed brain tissue that can grow and function like typical brain tissue.

It’s an achievement with important implications for scientists studying the brain and working on treatments for a broad range of neurological and neurodevelopmental disorders, such as Alzheimer’s and Parkinson’s disease.

Printing methods have limited the success of previous attempts to print brain tissue, according to Zhang and Yuanwei Yan, a scientist in Zhang’s lab.

Instead of using the traditional 3D-printing approach, stacking layers vertically, the researchers went horizontally. They situated brain cells, neurons grown from induced pluripotent stem cells, in a softer “bio-ink” gel than previous attempts had employed.

The results speak for themselves — which is to say, the cells can speak to each other. The printed cells reach through the medium to form connections inside each printed layer as well as across layers, forming networks comparable to human brains. The neurons communicate, send signals, interact with each other through neurotransmitters, and even form proper networks with support cells that were added to the printed tissue.

The printing technique offers precision — control over the types and arrangement of cells — not found in brain organoids, miniature organs used to study brains. The organoids grow with less organization and control.

“Our lab is very special in that we are able to produce pretty much any type of neuron at any time. Then we can piece them together at almost any time and in whatever way we like,” Zhang says. “Because we can print the tissue by design, we can have a defined system to look at how our human brain network operates. We can look very specifically at how the nerve cells talk to each other under certain conditions because we can print exactly what we want.”

The new printing technique should also be accessible to many labs. It does not require special bio-printing equipment or culturing methods to keep the tissue healthy, and can be studied in depth with microscopes, standard imaging techniques and electrodes already common in the field.

The researchers would like to explore the potential of specialization, though, further improving their bio-ink and refining their equipment to allow for specific orientations of cells within their printed tissue..

Sources:

Yuanwei Yan, Xueyan Li, Yu Gao, Sakthikumar Mathivanan, Linghai Kong, Yunlong Tao, Yi Dong, Xiang Li, Anita Bhattacharyya, Xinyu Zhao, Su-Chun Zhang. 3D bioprinting of human neural tissues with functional connectivity. Cell Stem Cell, 2024; 31 (2): 260 DOI: 10.1016/j.stem.2023.12.009

Materials provided by University of Wisconsin-Madison. Original written by Emily Leclerc. Note: Content may be edited for style and length.

University of Wisconsin-Madison. “Researchers 3D-print functional human brain tissue.” ScienceDaily. ScienceDaily, 1 February 2024. <www.sciencedaily.com/releases/2024/02/240201212823.htm>.

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