Researchers at Tel Aviv University have succeeded in designing spinal cord tissue that restored the ability to walk in mice in 80% of cases. A world first which could make it possible to treat paraplegia and tetraplegia in humans.
- Paraplegia and tetraplegia refer to paralysis of two or four limbs, caused by damage to the spinal cord or spinal cord.
- A spinal cord injury can cause paraplegia (paralysis of the lower limbs) or tetraplegia (paralysis of the lower and upper limbs) resulting in sensory and motor losses but also genito-sphincter disorders.
It is a revolutionary technology, which could, if transposed to humans, change the lives of thousands of people whose spinal cord lesions cause paralysis of the arms and/or legs.
For the first time, researchers from the Sagol Center for Regenerative Biotechnology, attached to Tel-Aviv University (Israel) have designed human spinal cord tissue in 3D and implanted it in a mouse model suffering from long-term chronic paralysis. term. The results, which were published in the journal Advanced Sciencehave a success rate of about 80% in restoring walking ability.
The creation of neural networks from extracellular matrix cells
“Other researchers had already managed to repair a spinal cord injury with stem cells, but it only worked if the cells were injected immediately after the injury. It is more complicated for chronic injuries, because over time, the lesion enlarges and is surrounded by scar tissue, which prevents stem cells from creating neural networks and integrating into the spinal cord, explain to Science and Future Professor Tal Dvir, who directed the work. However, people who suffer an injury due to an accident do not have the possibility of being treated immediately after the accident.
To circumvent this difficulty, the research team took a sample of fatty tissue from the patient’s belly by biopsy. This is made up of cells and an extracellular matrix (including substances such as collagens and sugars). After separating the cells from the extracellular matrix, the team used genetic engineering to reprogram the cells back to a state that resembles that of embryonic stem cells, i.e. cells capable of becoming n any type of cell in the body. A custom hydrogel was then created from the extracellular matrix to elicit no immune response or rejection after implantation. Finally, the stem cells were encapsulated in the hydrogel and, in a process that mimics embryonic development in the spinal cord, the researchers transformed the cells into 3D implants of neural networks containing motor neurons.
Clinical trials on humans within two years
These 3D human spinal cord implants were then implanted in laboratory models, divided into two groups: those who had been paralyzed for a short time (the acute model) and those who had been paralyzed for a long time – the equivalent of one year in terms humans (the chronic model). After implantation, 100% of lab models with acute paralysis and 80% of those with chronic paralysis regained their ability to walk.
“This is the first time in the world that implanted artificial human tissue has generated healing in an animal model of long-term chronic paralysis, which is the most relevant model for human paralysis treatments. emphasizes Professor Dvir. Millions of people around the world are paralyzed as a result of spinal injuries, and there is still no effective treatment to cure them. (…) Our goal is to produce personalized spinal cord implants for each paralyzed person, allowing the regeneration of damaged tissue without the risk of rejection.”
The researchers therefore hope to be able to test these neural tissue implants on humans soon. For this, they created the biotechnology company Matricelf and are currently in discussion with the US Federal Food and Drug Administration (FDA) to begin clinical trials within two years.
.
