A team from the University of Wisconsin–Madison has achieved a groundbreaking feat by developing the first-ever functional brain tissue using 3D printing technology.
This tissue is capable of forming connections and developing like real human brain tissue, making it an invaluable tool for neuroscientists to study brain cell communication and other brain functions. This development could potentially lead to new and better treatments for diseases such as Parkinson’s and Alzheimer’s. Parkinson’s disease is a neurological disorder that causes progressive damage to a person’s motor functions. It can affect a person’s thinking, mood, and memory in advanced stages. Alzheimer’s is also a neurological disorders that begin with mild memory loss and possibly leads to loss of the ability to carry on a conversation and respond to the environment. The risk of severe infections and life-threatening complications is higher for people in progressed stages of Alzheimer’s.
“It could change the way we look at stem cell biology, neuroscience, and the pathogenesis of many neurological and psychiatric disorders,” says neuroscientist Su-Chun Zhang, senior author of a new paper describing the research.
Zhang and his research team have developed a new method that can be used by many laboratories as it does not require any special bio-printing equipment. The tissue created through this method is easy to maintain in a healthy state and can be observed with microscopes and other typical laboratory equipment.
3D bioprinting is a process that is guided by a computer to build living structures by creating layers of materials, cells, and other components. This technology has immense potential to create tissues that are capable of replicating, and in some cases, even replacing the real tissue.
“Because we can print the tissue by design, we can have a defined system to look at how our human brain network operates,” says Zhang. “We can look very specifically at how the nerve cells talk to each other under certain conditions.”
To study health and diseases related to the human brain networks, it is essential to have a dependable model of living human neural tissues. Animal models are not capable of replicating the brain’s complexity in full.
Although 3D-printed tissues have been attempted, it is challenging to produce functional human brain tissue with proper connections between cells. The tissue structure must be kept intact while neurons mature, and supporting cells like astrocytes are necessary for the tissue to function correctly.
Previous attempts used non-biodegradable scaffolds, which hindered neural cells from easily migrating. However, the team used horizontal layering of neurons derived from induced pluripotent stem cells instead of the typical vertical layering. Additionally, they placed the neurons in a softer ‘bio-ink’ gel compared to previous methods.
Within just a few weeks, their printed tissue cells can create brain-like networks within and between layers. These neurons can communicate, send signals, use neurotransmitters, and even form networks with added supporting cells.
“The tissue still has enough structure to hold together but it is soft enough to allow the neurons to grow into each other and start talking to each other,” explains Zhang.
“Even when we printed different cells belonging to different parts of the brain, they were still able to talk to each other in a very special and specific way.”
Focusing on a single topic can lead to overlooking key elements, as the brain operates in networks. This technique of 3D-printing brain tissue enables more precise observation of cellular interactions.
“We printed the cerebral cortex and the striatum and what we found was quite striking,” Zhang says.
The pattern of axons projecting in the printed brain tissue resembles that of the human brain, where cortical neurons project axons to the striatum.
Unlike brain organoids which are miniature lab-grown organs used for brain research, the 3D-printing method used in this study allows for control over cell types and arrangements with great precision.
Although the mature neurons’ direction in the printed tissue cannot be controlled and the natural structure seen in brain organoids is lacking, Zhang and colleagues argue that it complements organoids as a valuable tool for studying the brain under different conditions.
“It can be used to look at the molecular mechanisms underlying brain development, human development, developmental disabilities, neurodegenerative disorders, and more,” Zhang explains.
The team aims to enhance their methodology to produce brain tissues that are more precise, by utilizing cells that can be guided.
This news is a creative derivative product from articles published in famous peer-reviewed journals and Govt reports:
References:
1. What Is Parkinson’s Disease? https://www.sciencealert.com/parkinsons-disease
2. What Is Alzheimer’s Disease And Is There a Way to Treat It? https://www.sciencealert.com/alzheimer-s-disease
3. Yan, Yuanwei, et al. “3D bioprinting of human neural tissues with functional connectivity.” Cell Stem Cell 31.2 (2024): 260-274.
4. Sousa, André MM, et al. “Evolution of the human nervous system function, structure, and development.” Cell 170.2 (2017): 226-247.
5. Beaulieu-Laroche, Lou, et al. “Enhanced dendritic compartmentalization in human cortical neurons.” Cell 175.3 (2018): 643-651.
