Nanoparticles laced with a medicine for Tylenol poisoning and sent into the brains of baby rabbits eased symptoms of cerebral palsy, according a study that points to a potential approach for treating humans with the disorder.
Using nanoparticles called dendrimers, researchers were able to penetrate the brain’s natural barriers to deliver a medicine into the animals, quelling the inflammation that can lead to cerebral palsy, according to research published today in the journal Science Translational Medicine.
Cerebral palsy, a lifelong neurological disorder that affects movement, is caused by an abnormality to an infant’s brain that occurs in the womb or early in life. In the study, newborn rabbits with the condition were injected with the therapy, and within five days showed “significant” improvement in their ability to move, as well as reduced inflammation in the brain.
“Reaching the inflamed cells in the brain has been a long-standing major challenge,” said Rangaramanujam Kannan, the study author, in a telephone interview. “Dendrimers not only go into brain, they go specifically into the cells called activated mycrogia that are the source of the problem. So then we attached a drug to it, and shut them down in a targeted manner.”
The scientists attached the anti-inflammatory drug called N-acetylcysteine to the nanoparticles, which are the tiniest engineered materials. The medicine, long used as an antidote for Tylenol poisoning, helped suppress immune cells called mycrogia and astrocytes. The cells, which respond to the site of injury, can cause damage to normal brain tissue as they spur an overheated inflammatory response.
The activated mycrogia cells are also linked to other neurological diseases such as Alzheimer’s, stroke, Parkinson’s, and multiple sclerosis, said Kannan.
There is no cure for cerebral palsy, a disorder that is diagnosed in as many as four infants of 1,000 worldwide, according to the U.S. Centers for Disease Control and Prevention. People with the cerebral palsy often need special equipment to walk, and can suffer from stiff muscles, uncontrollable movements and poor balance and coordination.
Researchers focused on rabbits because like humans, they start developing motor skills before birth and complete it after, while most other mammals finish before being born.
Since humans aren’t typically diagnosed with cerebral palsy until they are at least 18 months old, researchers will test to see if the therapy has the same effect on rabbits when injected later in life, said Kannan, an ophthalmologist with John Hopkins University in Baltimore. Another hurdle is that dendrimers haven’t been approved for use in humans, he said.
“I do not know if it will work in humans, however, we have made a big paradigm shift in the way people think about this disease, because people think this cannot be reversed,” he said. “We are very bullish about the prospect of this approach.”