How 3D printing can help repair brain injuries

The brain is the most complex and important organ in our body. It controls everything we do, think and feel. The brain is made up of billions of cells called neurons, which communicate with each other through electrical and chemical signals. The neurons are organized into different layers and regions, each with its own function and structure.

Sometimes, the brain can get injured by accidents, strokes, tumors or surgeries. These injuries can damage the outer layer of the brain, called the cerebral cortex, which is responsible for many cognitive, motor and sensory abilities. For example, if you hit your head hard, you might lose your memory, your speech or your movement. Or if you have a stroke, you might have trouble seeing, hearing or understanding.

Unfortunately, there is no effective treatment for severe brain injuries. The damaged neurons cannot be replaced or repaired by the body. The current therapies can only help to reduce the symptoms or prevent further damage. But they cannot restore the lost functions or structures of the brain.

What is the solution?

A possible solution for brain injuries is to use tissue engineering. This is a technique that uses living cells to create artificial tissues or organs that can replace or repair the damaged ones. For example, if you have a burn on your skin, you might get a skin graft from another part of your body or from a donor. This is a form of tissue engineering.

But how can we do tissue engineering for the brain? The brain is much more complicated than the skin. It has different types of cells, different layers and different shapes. It also has to connect and communicate with the rest of the brain and the body.

To do tissue engineering for the brain, we need to use stem cells. Stem cells are special cells that can turn into any type of cell in the body. For example, if you put stem cells in the heart, they can become heart cells. If you put them in the liver, they can become liver cells. And if you put them in the brain, they can become brain cells.

But how can we make sure that the stem cells become the right type of brain cells? And how can we arrange them in the right way to mimic the structure of the brain? This is where 3D printing comes in.

3D printing is a technique that uses a machine to create objects layer by layer from a material. For example, if you want to make a cup, you can use a 3D printer to print it from plastic or metal. You can also design the shape and size of the cup on a computer before printing it.

But 3D printing can also be used for biological materials. For example, if you want to make a piece of bone, you can use a 3D printer to print it from calcium and collagen. You can also design the shape and size of the bone on a computer before printing it.

And 3D printing can also be used for stem cells. For example, if you want to make a piece of brain tissue, you can use a 3D printer to print it from stem cells. You can also design the type and arrangement of the stem cells on a computer before printing them.

How does it work?

Researchers from Oxford University have developed a new method to 3D print stem cells into brain tissue. They used human stem cells that were taken from skin or blood samples and reprogrammed to become pluripotent. This means that they can turn into any type of cell in the body.

The researchers then used different chemicals and factors to make the stem cells become neural progenitor cells. These are immature cells that can turn into different types of neurons or glial cells in the brain.

The researchers then mixed the neural progenitor cells with a liquid that could be printed by a 3D printer. They called this liquid bioink. They made two types of bioink: one for the upper layer of the cerebral cortex (called layer II/III) and one for the lower layer (called layer V/VI). These two layers have different types and functions of neurons.

The researchers then used a 3D printer to print droplets of bioink onto a surface. They printed two layers of bioink: one on top of another. They printed them in a way that mimicked the shape and size of a column in the cerebral cortex. A column is a basic unit of organization in the cortex that contains thousands of neurons.

The researchers then let the printed tissue grow in a dish for several weeks. They found that the neural progenitor cells turned into mature neurons and glial cells in each layer. They also found that each layer expressed specific markers that showed their identity and function.

The researchers then tested whether the printed tissue could integrate with real brain tissue. They took slices of mouse brain and placed them next to the printed tissue. They found that the printed tissue connected with the mouse brain tissue. They also found that the printed and mouse neurons could send and receive signals to each other. This showed that the printed tissue was functional and compatible with the host tissue.

What are the benefits and challenges?

The new method of 3D printing stem cells into brain tissue has many potential benefits. It could provide a way to create personalized implants for patients with brain injuries. The implants could be made from the patient’s own stem cells, which would avoid immune rejection or ethical issues. The implants could also be designed to match the shape and structure of the damaged area of the brain. The implants could also help to restore the lost functions or structures of the brain by integrating with the host tissue and communicating with the rest of the brain.

The new method also has many scientific applications. It could be used to study how the human cerebral cortex develops and works. It could also be used to test new drugs or treatments for brain diseases or disorders. It could also be used to improve our understanding of how the brain processes information and generates cognition.

However, the new method also has many challenges and limitations. It is still very difficult to 3D print complex and realistic brain tissues that have multiple layers and regions. It is also still unclear how well the printed tissues can survive and function in a living brain. It is also still unknown how safe and effective the printed tissues are for human patients.

Therefore, more research and development are needed before 3D printing stem cells into brain tissue can become a reality for clinical or scientific use.