In a world first, scientists at the University of Wisconsin-Madison have achieved the remarkable feat of 3D-printing human brain tissue that can grow and function like real, organic tissue.
“This could prove to be a profoundly impactful model to enhance our understanding of brain cell interaction and intricate neural networks in humans,” commented professor of neuroscience and neurology at the University of Wisconsin-Madison Su-Chun Zhang, the research’s senior author, in a statement. “It has the potential to revolutionize our perspective of stem cell biology, neuroscience, and the pathogenesis of numerous neurological and psychiatric disorders.”
This groundbreaking development could equip researchers with a flexible and efficient tool for addressing major challenges in contemporary neuroscience, such as developing treatments for debilitating diseases like Alzheimer’s and Parkinson’s.
The rapid advancements in 3D printing technology in recent years have led to a multitude of remarkable applications. Whether your pet tortoise requires a set of wheels, you’re interested in cooking a delicious two-course meal, or you’re intrigued by a robot snake growing towards the light, 3D printing can aid in those pursuits.
Despite the numerous applications of 3D printing, the creation of 3D-printed brain tissue has only seen moderate success. The breakthrough came when the UW-Madison team chose to tackle the issue from a completely different angle.
Rather than building layers upward as is customary in conventional 3D printing, they opted to proceed sideways. They cultured brain cells from induced pluripotent stem cells, aligning them within a malleable gel they’ve dubbed “bio-ink”.
“The tissue maintains a certain structure to stay intact but it’s soft enough to enable the neurons to intertwine and initiate communication,” elucidated Zhang, which is crucial if you want your tissue to grow and evolve as it would in a human body.
“Our tissue remains fairly thin, which facilitates in the neurons receiving ample oxygen and nutrients from the growth media,” contributed the main author, Yuanwei Yan.
Neurons can permeate through each layer of the 3D printed gel, creating interconnected pathways that mimic the intricate network within the brain. These neurons can transmit signals, establish networks, and interact via the release of neurotransmitters. Another type of cell, the astrocytes, were also included in the tissue for interaction with the neurons.
“Our lab possesses the unique ability to generate any type of neurons whenever required. Subsequently, we can assemble them anytime and in any manner we prefer,” commented Zhang.
According to the authors, this level of accuracy and control surpasses what is possible with so-called “mini brains“. These are human brain organoids developed from stem cells. To further validate their 3D printing system, they produced tissues from two distinct areas of the brain.
“We 3D printed the cerebral cortex and the striatum. The results were quite astounding. Despite being from different parts of the brain, the different cells managed to communicate in a very specific and unique manner,” Zhang further explained.
The team anticipates that their methodology will be widely implemented due to its simplicity and minimal need for sophisticated apparatus. Even so, they are intensely focusing on enhancements for specific use-cases.
“Historically, our attention has been concentrated on a single aspect, which often leads to overlooking some key elements,” commented Zhang. “Our cognition functions in networks. The ultimate goal is to imitate this network functionality in the brain tissues we print because cells are not solitary operators. They constantly interact with each other. That’s the fundamental mechanism on which our brain operates and understanding it in its entirety is the only way to truly comprehend its workings.”
The findings of this research are available in the scientific journal Cell Stem Cell.