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A Shot of Hope

Jack Kessler received the call that every parent dreads. In January 2001, his then–15-year-old daughter had suffered an accident while downhill skiing, and a dislocated vertebra in her lower back had crushed her spinal cord. Kessler, a professor of neurology at the Feinberg School of Medicine, knew his daughter would likely never walk again.

At the time, Kessler’s research centered on regenerating the nervous system in relation to peripheral nerve disorders. But the night of his daughter’s injury, he decided to focus intellectually and emotionally on helping people with spinal cord injuries.

Kessler recently co-authored a study that suggests significant progress toward achieving that goal.

After a spinal cord injury, a significant amount of secondary nerve damage is caused by inflammation and internal scarring that inhibit the ability of the nervous system to repair itself.

Kessler and Northwestern Medicine co-author Stephen Miller demonstrated that a biodegradable nanoparticle injected after a spinal cord trauma prevented the inflammation and scarring. As a result, mice with a spinal cord injury receiving the nanoparticle injection were able to walk better after the injury than those that didn’t receive it.

“It’s not a cure, because it would not prevent the initial damage,” Kessler says. “But it would prevent this huge wave of secondary damage that takes what would have otherwise been a much less severe injury and makes it a much more devastating one.”

After a spinal cord injury, blood cells that normally couldn’t enter the nervous system breech the protective blood-brain barrier and flood the injury site. They release noxious chemicals, called inflammatory cytokines, which call in additional inflammatory blood cells. These cells further damage the central nervous system tissue by causing neuronal cell death and scar formation that blocks recovery from paralysis. The nanoparticles work by binding to the cells that cause the inflammation and diverting them to the spleen.

Kessler believes the nanoparticles could be stored in a syringe at room temperature and administered immediately after injury by paramedics in ambulances or doctors in hospitals. “There isn’t anything else around like that,” he says.

If these nanoparticles are as successful in humans as they were in mice, they could be a simple way to drastically improve quality of life. Miller, the Judy Gugenheim Research Professor of Microbiology-Immunology at Feinberg, says the injured mice that are treated with the nanoparticle “don’t come back to normal, but they do twice as well as animals that are not treated.”

With a severe injury, Kessler says, it would be the difference between somebody not being able to move their legs at all versus being able to move their legs a little. In a more moderate injury, it would be the difference between being able to move their legs and begin to try to walk versus being able to use their legs in a coordinated fashion to be able to walk, though perhaps not normally.

The nanoparticle was developed in Miller’s lab for the treatment of autoimmune and allergic diseases and transplants. He reached out to Kessler to see if the nanoparticles could be used to mitigate spinal cord damage. Both doctors are excited about the partnership.

“Our two labs do very different things,” Kessler says, “and in many ways, that’s the best way to do science, because there’s no way we could have done what we did without Dr. Miller. I think it’s fair to say there’s no way he could have done this without us. So that’s the kind of win-win situation you look for.”

Further studies will need to confirm the safety of the injected nanoparticle, Kessler says, but he noted scientists haven’t seen any signs of toxicity so far. The technology is being developed commercially by Cour Pharmaceuticals Development Co., which is working with Miller to bring this new approach to patients. Miller is a co-founder of Cour and a member of its scientific advisory board. 

Kessler says the therapy would not help people like his daughter who are already paralyzed, but it could help in the immediate aftermath of an injury like the one she suffered. “You never try to promise people that something is going to work, because it’s not fair,” he says. “But do I think there’s every reason to believe that this could have an impact? Yes, I do.”

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