In the United States, more than 20 million children and adults are affected by debilitating neurodegenerative and central nervous system (CNS) diseases. Although multiple drugs exist to treat and potentially cure these diseases, 98 percent of all potential pharmaceutical agents cannot reach the CNS directly: They are unable to cross the blood–brain barrier.
Many attempts have been made to deliver drugs across this barrier using methods such as osmotic disruption and catheter implantation. These methods, however, are temporary and prone to infection and dislodgement.
HMS researchers in the Department of Otology and Laryngology at Massachusetts Eye and Ear have recently demonstrated what may be the first known method to permanently bypass the blood–brain barrier. The method, which uses the lining of the nose as a delivery portal, may offer new treatment options to people with neurodegenerative and CNS disease. The study was published in April in PLoS ONE.
Inspired by recent advances in human endoscopic transnasal skull-base surgical techniques, the investigators developed a mouse model of a novel method that used a patient’s own tissues to create a semipermeable window in the blood–brain barrier. The researchers then used the model to evaluate whether transmucosal permeability would allow drugs to be delivered directly to the brain.
The scientists showed that the membranes are capable of delivering molecules to the brain that are up to 1,000 times larger than those excluded by the blood–brain barrier.
“Since this is a proven surgical technique known to be safe and well tolerated, these data suggest that these membranes might be used to permanently bypass the blood–brain barrier using a patient’s own tissue,” says Benjamin Bleier, an HMS assistant professor of otology and laryngology at Mass Eye and Ear.
“Future studies,” Bleier adds, “will be directed toward developing clinical trials to test this method in patients who have already undergone these endoscopic surgeries.”