Printing Human Brains - Fact or Fiction?

Thanks to 3D printing, it is easy to print everyday objects, from simple mugs to sophisticated prosthetic medical devices. But what about printing something as complicated as living human tissue? This challenge has kept many scientists awake at night, especially neurologists. This is because neurologists study the human brain, which, compared to the brains of other animals, displays different biological properties. In particular, the human brain has different subtypes of neurons, the cell type predominantly found in the brain. 3D bioprinting could sidestep this problem by creating brain tissues with the desired neuron properties and subtypes. Hence, it would be a more reliable model than animals for studying neurological disorders and for drug testing.

Despite the technology’s great promise, most 3D-bioprinted neural tissues do not function properly because the thick 3D environment, created by printing different neuron subtypes on top of each other, blocks nutrient and oxygen flow. In a recent study, researchers at the University of Wisconsin-Madison may have solved this issue by printing different neuron subtypes horizontally next to each other rather than vertically on top of each other, creating much thinner 3D tissues. Due to better oxygen and nutrient flow, the neurons successfully carried out their basic function: firing electrical signals, which were transmitted from one neuron to the other, enabling communication between neurons of the same and different subtypes.

Furthermore, the researchers used their system to successfully model Alexander’s disease, a neurodegenerative condition. This newly developed platform therefore provides a promising tool to study neurodegenerative disease in a more human-relevant context compared to mice models. The next goal is to streamline the bioprinting process to facilitate the use of 3D-bioprinted brain tissue for basic human disease research and drug screens.

This study was performed at the University of Wisconsin-Madison by scientist Yuanwei Yan (PhD) in the lab of Su-Chun Zhang (MD, PhD), professor of Neuroscience and member of the Waisman Center.

Managing Correspondent: Allegra Carlotta Scarpa

Press Article: 3D printer creates brain tissue that acts like the real thing (News from Science)

Original Journal Article: 3D bioprinting of human neural tissues with functional connectivity (Cell Stem Cell)

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