The latest breakthrough in 3D printing technology has brought scientists closer to replicating human brain tissue in the laboratory. The tissue created through this method behaves remarkably like real human brain tissue, marking a significant milestone in neuroscience research.
This printed tissue, less than 0.01 inch (0.02 centimeter) thick, contains both nerve cells and supporting glial cells, forming intricate networks similar to those found in a natural human brain. The process involved a biological printer that deposited stem-cell-laden gel in horizontal layers, which were then induced to differentiate into brain cells using specific chemical cues.
Published in the journal Cell Stem Cell on Feb. 1, the study’s authors highlight the potential of this technology to complement existing models of the human brain, such as brain-on-a-chip devices and cerebral organoids. Unlike organoids, the 3D printing technique allows for precise control over cell placement and significantly accelerates the formation of neural connections.
Dr. Su-Chun Zhang, co-senior study author and professor of neuroscience and neurology at the University of Wisconsin-Madison, notes that this rapid development makes the printed brain tissue an attractive tool for drug testing, particularly for diseases affecting brain function like neurodegenerative and psychiatric disorders.
A key innovation of the printing approach lies in the gel’s softness, which enables cells to establish proper connections while maintaining structural integrity. Unlike traditional vertical stacking methods, horizontal layering ensures optimal exposure to oxygen and nutrients, fostering the development of functional neurons and glia.
Despite these advancements, the technique still faces challenges. The gel’s softness impedes the printing of multiple layers in succession, slowing down the process. Additionally, nutrient demands limit individual layer thickness, constraining overall tissue size.
Acknowledging these limitations, Zhang emphasizes the iterative nature of scientific progress and expresses optimism about refining the technology in the future. While the printed model may not fully replicate the complexities of the human brain, it represents a significant step forward in our quest to understand and emulate its remarkable capabilities.