The first human brain tissue capable of growing and functioning just like the real thing has been 3D printed: it can be used to study neurological diseases such as Parkinson's and Alzheimer's, as well as speed up drug testing.
The result is published in Cell Stem Cell by researchers at the University of Wisconsin-Madison led by neuroscientist Su-Chun Zhang.
“This could be an extremely powerful model to help us understand how brain cells and parts of the brain communicate in humans,” says Su-Chun Zhang.
“It could change the way we look at stem cell biology, neuroscience, and the pathogenesis of many neurological and psychiatric disorders.”
To print functioning brain tissue, the researchers started with induced pluripotent stem cells that they caused to differentiate into neurons.
Once ready, the neural cells were used to produce a living ink with a softer consistency than usual, which was laid down not in vertically stacked layers, as happens with the traditional 3D printing technique, but horizontally.
The cells were then positioned like many pencils placed next to each other on a table.
In this way, a brain tissue was obtained that "still has enough structure to remain together, but is soft enough to allow the neurons to grow and start talking to each other", explains Zhang.
The cells are thus able to form new connections within each printed layer and also between different layers, generating circuits comparable to those of the human brain.
Neurons communicate, send signals, interact with each other through neurotransmitters and form real networks with support cells added to the tissue.
“We printed the cerebral cortex and striatum and what we found was quite surprising,” Zhang continues.
“Even when we printed 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 new printing technique also allows the types of cells and their arrangement to be controlled with extreme precision, which is not possible with brain organoids.
Reproduction reserved © Copyright ANSA