Scientists at Northwestern University in Illinois have taken a major step forward in the fight against paralysis by creating organoids (small replicas of organs grown from stem cells) capable of precisely replicating human spinal cord injuries. According to IFL Science, these models were then used as a test for an already promising experimental therapy in mice: “dancing molecules”.
The human spinal cord, unlike that of certain reptiles or amphibians, regenerates very poorly. An injury causes cell death, intense inflammation and the formation of a so-called glial scar – specific to lesions of the nervous system – which physically and chemically blocks nerve regrowth. The new organoids reproduce this process with an unprecedented degree of fidelity. The team claims to have developed the most advanced model to date to study human spinal cord trauma.
After four months of culture, the mini marrows reach approximately 3 millimeters in diameter, a size sufficient to simulate complex lesions. These organoids integrate microglia, the immune cells of the central nervous system, essential for understanding the actual inflammatory response after trauma.
Dancing molecules
The researchers inflicted two types of injuries on the organoids, mimicking a stab and a violent shock. They then applied a therapy called “dancing molecules,” an injectable nanofiber gel that assembles around the wound, stimulates the cells and then breaks down into nutrients. In mice, a single injection was enough to quickly reverse experimental paralysis.
In the miniature human model, the results are spectacular. “After application of our therapy, the glial scar faded to almost undetectable, and we observed nerve regrowth comparable to that seen in animals”explains Professor Samuel Stupp, at the origin of the treatment. Neurites, extensions of neurons, do not just grow: they are organized in an orderly manner, a sign of potential functional reconstruction.
Conversely, control molecules incapable of “dancing” did not trigger this regeneration. The rapid movement of the nanofibers would promote contacts with cellular receptors, multiplying repair signals.
No clinical trial has yet been announced. The team is now working on even more complex organoids, integrating for example blood vessels and models of ancient injuries. The stakes are high: each year, between 250,000 and 500,000 people suffer a spinal cord injury worldwide. If the therapy is confirmed in humans, it could transform the management of these traumas and, ultimately, extend to other neurological disorders such as head trauma.
