Researchers could help to repair brain injuries by 3D printing human stem cells.

A new technique has been developed that could help people who suffer from brain injuries.

Researchers from the University of Oxford were able to 3D print neural cells to mimic the cerebral cortex or the outermost layer of the brain.

It is the part responsible for important functions such as language, memory, reasoning or decision-making.

When these 3D-printed cells were implanted into mice brain slices, they integrated with the host tissue, the university said. The findings were published in the journal Nature Communications.

“This advance marks a significant step towards the fabrication of materials with the full structure and function of natural brain tissues,” said lead author Dr Yongcheng Jin from the Department of Chemistry at the University of Oxford.

“The work will provide a unique opportunity to explore the workings of the human cortex and, in the long term, it will offer hope to individuals who sustain brain injuries,” he added.

No treatment for brain injuries

The findings come as Europeans tune in to watch the Rugby World Cup, despite impending lawsuits against the sport’s governing bodies related to brain injuries.

Traumatic brain injuries can be caused by contact sports, trauma, or stroke and typically result in damage to the cerebral cortex.

Even though millions of people globally suffer from these injuries, there are no effective treatments.

Tissue regenerative therapies, which use a person’s own stem cells to repair damaged tissue, are one of the options being explored to treat these types of brain injuries.

But there hasn’t been a way to make them properly interact with the natural tissue of the brain.

How did the researchers do this?

They used a technique called “droplet printing” to create two “bioinks” from stem cells to produce a two-layered structure.

The stem cells have the potential to turn into the cell types found in most human tissues and can be easily derived from cells harvested from patients themselves, and not trigger an immune response.

Researchers then proceeded to test the tissues ex vivo, by implanting them into mouse brain slices – a dissected section of their brain.

They found that the brain cells integrated well with the existing mouse brain cells, with the human and mouse cells “communicating with each other”.

Researchers now want to improve their 3D printing method to make brain tissues that better mimic a human brain.

“Human brain development is a delicate and elaborate process with a complex choreography. It would be naïve to think that we can recreate the entire cellular progression in the laboratory,” said senior author Professor Zoltán Molnár from Oxford’s Department of Physiology, Anatomy and Genetics.

Nonetheless, these results show substantial progress “to form the basic functional units of the cerebral cortex,” he added.

In the future, these brain tissues could help to treat brain injuries, test new drugs, and study how the brain develops and works.