Scientists at the University of Wisconsin–Madison claim a significant breakthrough with the creation of the first 3D-printed brain organoids that exhibit functions akin to natural brain tissue. Senior author Su-Chun Zhang explains that these organoids, developed from stem cells, showcase communication between neurons, signal transmission, interactions through neurotransmitters, and the formation of networks with support cells within the printed tissue.

The challenge in creating brain organoids lies in the limited control over their final structure when stem cells self-assemble into three-dimensional tissues. This lack of control hinders researchers in designing the best brain organoids for their studies. While some have attempted 3D bioprinting, challenges include keeping soft, cell-filled “inks” in place and preventing the use of stiffer substances or scaffolding that hinder natural cell connections.

In this study, the UWM team adopted a different approach. They coaxed stem cells into developing different brain cell types, creating a printable “bioink” by mixing these cells with a hydrogel. Unlike traditional vertical layer stacking, the team opted for a horizontal approach, placing bioink strips next to each other. Although the 3D-printed brain organoids were only 50 micrometers tall, this thinness allowed for optimal oxygen exposure to neurons. The horizontal arrangement facilitated the formation of natural connections between different cell types in different layers, mimicking the networks found in natural brain tissue.

Senior author Su-Chun Zhang expresses optimism about the model’s potential to enhance understanding in stem cell biology, neuroscience, and neurological and psychiatric disorders. The team plans to refine their technique, seeking greater control over cell orientation in 3D-printed brain organoids, potentially through adjustments to their bioink. Given its compatibility with commercial bioprinters and standard imaging technology, the technique holds promise for adoption by other labs in various research endeavors.

By Impact Lab