Paralyzed mice walk again thanks to promising drug

The discovery may give hope to people with paralysis. Researchers have successfully made mice with spinal cord injuries who had their hind legs completely paralyzed walk again. A single injection of synthetic nanofibers was enough according to their study, published this Thursday in the journal Science.

This new type of therapy uses nanofibers to mimic the natural environment of the spinal cord. Each nanofiber, which is 10,000 times thinner than a hair, is made up of hundreds of thousands of molecules called peptides, which transmit signals to trigger cell repair and regeneration.

A major breakthrough that could revolutionize treatments for spinal cord injuries, for which there is no cure. “I am extremely excited and confident this will help patients”said Professor Samuel Stupp, of Northwestern University in Chicago, behind the study. The team plans to ask the Food and Drug Administration (FDA), the US drug regulator, for authorization to conduct a human trial as early as next year and hopes to be able to begin trials within two years.

The therapy, which comes in gel form, was injected into the tissues surrounding the spinal cord of lab mice 24 hours after their spines were severed. The researchers decided to wait a day because humans who have suffered spinal injuries from car crashes, gunshot wounds, or other traumas usually don’t get treatment sooner.

The results are dramatic: three to four weeks later, the mice ‘spines were doing almost as well as before the injury. The study also found that the treatment caused the regrowth of severed extensions of neurons called axons, reduced scar tissue, which can become a physical barrier to repair, and the formation of new blood vessels.

The breakthrough comes after a number of high-profile studies of spinal cord injury over the past decade that have yet to translate into approved treatments for patients. According to Samuel Stupp, the drug is simple and safe because the materials break down in a matter of weeks and become nutrients for the cells.

Besides paralysis, this gel is the first of its kind and could lead to a new generation of drugs called “supramolecular”, composed of an assembly of molecules and not of a single molecule.