Scientists from the University of Wisconsin in Madison (USA) reported about the world’s first 3D printing of functional human brain tissue. The development will help in studying the functioning of the brain and its individual structures, as well as in the search for methods of treating neurological disorders and diseases. As the scientists pointed out in an article in the journal Cell Stem Cell, the tissue they printed was able to “grow and function like normal brain tissue“
“This could be an extremely powerful model that will help us understand how cells and parts of the brain interact in humans,” said Su-Chun Zhang, a professor of neuroscience at the Weissman Center at the University of California, Madison. “This could change our view of stem cell biology, neurology, and the pathogenesis of many neurological and psychiatric disorders.”
Scientists emphasize that, unlike the increasingly popular method of growing so-called organoids – a kind of miniature copies of real human organs from corresponding cells – the 3D printing method provides sufficient precision to control the types of cells and their location.
To confirm their words, the scientists printed cortical and striatal tissues. Neurons began to form connections in and between both types of tissue, and also showed signs of activity at the operating level neurotransmitters. Through the synaptic gap between one neuron and another, the signal is transmitted chemically using, among other things, neurotransmitters. All this came to life and worked in fabrics printed on a 3D printer.
The scientists said that the subtlety in their proposed printing process lies in the use of bioink – a gel that binds cells – of such a density that no longer allows the tissue to spread and, at the same time, provides neurons and their processes with free growth within the composition. Also, the proposed method emphasizes horizontal printing rather than vertical printing. In this case, thin layers of nervous tissue are better supplied with oxygen and nutrients.
“We printed the cerebral cortex and striatum, and what we found was quite amazing. Even when we printed different cells from different parts of the brain, they could still communicate with each other in a very special way.” Professor Zhang said in a press release.