Cornell University researchers may have solved a 100-year puzzle: How to safely open and close the blood-brain barrier so that therapies to treat Alzheimer’s disease, multiple sclerosis and cancers of the central nervous system might effectively be delivered.
The researchers found that adenosine, a molecule produced by the body, can modulate the entry of large molecules into the brain. For the first time, the researchers discovered that when adenosine receptors are activated on cells that comprise the blood-brain barrier, a gateway into the blood-brain barrier can be established. Although the study was done on mice, the researchers have also found adenosine receptors on these same cells in humans. They also discovered that an existing FDA-approved drug called Lexiscan, an adenosine-based drug used in heart imaging in very ill patients, can also briefly open the gateway across the blood-brain barrier.
The blood-brain barrier is composed of the specialized cells that make up the brain’s blood vessels. It selectively prevents substances from entering the blood and brain, only allowing such essential molecules as amino acids, oxygen, glucose and water through. The barrier is so restrictive that researchers couldn’t find a way to deliver drugs to the brain – until now.
“The biggest hurdle for every neurological disease is that we are unable to treat these diseases because we cannot deliver drugs into the brain,” said Margaret Bynoe, associate professor of immunology at Cornell’s College of Veterinary Medicine ”Big pharmaceutical companies have been trying for 100 years to find out how to traverse the blood-brain barrier and still keep patients alive,” said Bynoe, who with colleagues have patented the findings and have started a company, Adenios Inc., which will be involved in drug testing and preclinical trials.