This handout picture obtained from Northwestern University on November 10, 2021 shows a longitudinal spinal cord section treated with the most bioactive therapeutic scaffold; regenerated axons (red) regrew within the lesion Photo: Northwestern University via AFP / Handout
What’s more, an insulating layer of axons called myelin that is important in transmitting electric signals had reformed, blood vessels that deliver nutrients to injured cells had formed, and more motor neurons survived.
A key discovery by the team was that creating a certain mutation in the molecules intensified their collective motion and heightened their efficacy.
This is because receptors in neurons are naturally in constant motion, Stupp explained, and increasing the motion of the therapeutic molecules within the nanofibers helps connect them more effectively with their moving targets.
The researchers in fact tested two versions of the treatment — one with the mutation and one without — and found that mice that received the modified version regained more function.
The gel developed by the scientists is the first of its kind, but could usher in a new generation of medicines known as “supramolecular drugs,” because the therapy is an assembly of many molecules rather than a single molecule, said Stupp.
According to the team, it is safe because the materials biodegrade within a matter of weeks and become nutrients for cells.
Stupp said he hopes to rapidly move direct to human studies next without the need for further animal testing, such as on primates.
This is because the nervous system is highly similar across mammal species and “there is nothing out there to help spinal cord injury patients, and this is a huge human problem,” he said.
According to official statistics, nearly 300,000 people are living with a spinal cord injury in the United States alone. Their lifespan is shorter than people without spinal injury, and has not improved since the 1980s.
“The challenge will be how the FDA will look at these therapies because they’re completely new,” predicted Stupp.