Nanoparticle Injection After Spinal Cord Injury Reduces Inflammation, Scarring

Inflammation and scarring that occur in patients after spinal cord injury can be treated and prevented by injecting a biodegradable nanoparticle.

A biodegradable nanoparticle infusion can aid in treating spinal cord trauma by preventing inflammation and internal scarring, reveals a new Northwestern Medicine study.

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

‘Injecting the biodegradable nanoparticles into the blood stream can prevent inflammation and scarring that occurs after a spinal cord injury.’

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.

The treatment could potentially limit secondary damage to the spinal cord in humans after an injury, if administered a few hours after the accident in an emergency room or by paramedics in an ambulance. The study was published in Neurobiology of Disease.

"It’s not a cure. There is still the original damage, but we were able to prevent the secondary damage," said co-senior author Dr. Jack Kessler, a professor of neurology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine neurologist.

Autonomic Dysreflexia - Causes, Symptoms, Diagnosis, Treatment, Prevention
Autonomic dysreflexia is a condition that occurs in patients with spinal cord injuries especially in the T5 and T6 levels. This condition is characterized by hyper activity of the autonomic nervous system.

"It’s an exciting potential treatment. We really believe this is something we’ll be able to take to the clinic."

Further studies would need to confirm the safety of the injected nanoparticle, Kessler said, but he noted scientists haven’t seen any signs of toxicity so far.

Spinal Cord Injury - Causes, Symptoms, Diagnosis, Treatment & Prevention
Spinal cord injury is an injury to the spinal cord that results in temporary or permanent changes in its function.

The nanoparticles work by binding to the cells that cause the inflammation inflammatory monocytes and diverting them to the spleen. The particles are made of poly(lactic-co-glycolic) acid, a biocompatible substance already approved by the Food and Drug Administration (FDA) for use in re-absorbable sutures.

Developed in the lab of Northwestern scientist Stephen Miller, the particles also are FDA approved as an investigational drug for a new clinical trial in celiac disease.

Spinal Injury - Symptom Evaluation
Spinal Injury refers to damage to spinal cord that runs below the brain through the back. Injury to spinal cord is a severe injury as the damage is irreversible and it can be life-threatening.

"The study results suggest nanoparticle infusion could offer a novel and practical potential treatment for human spinal cord injury, a condition for which there are currently no effective treatments," said Miller, the Judy Gugenheim Research Professor of Microbiology-Immunology at Feinberg.

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.

Two types of neurons die. One type myelin surrounds the nerve fibers and allows them to carry signals through the nervous system. If the myelin sheath is lost, the cells can no longer conduct signals. The other cells that die are axons, the long fibers extending from the neurons that carry signals from neuron to neuron.

"The new treatment is unusual because it is potentially immediately translatable to human beings," Kessler said. "All we have to do is literally inject these beads into the blood stream. It doesn’t require surgery or any fancy intervention."

The tiny beads also are very stable and can be kept in a syringe, Kessler noted. "An emergency medical technician at the site of an accident or somebody in an emergency room when someone is brought in can give this injection immediately," he said.

Source-Eurekalert