A drug-delivery technique to bypass the blood-brain barrier
Researchers have developed a new technique to deliver drugs across the blood-brain barrier. Their findings lend hope to patients with neurological conditions that are difficult to treat due to a barrier mechanism that prevents approximately 98 percent of drugs from reaching the brain and central nervous system.
“Although we are currently looking at neurodegenerative disease, there is potential for the technology to be expanded to psychiatric diseases, chronic pain, seizure disorders, and many other conditions affecting the brain and nervous system down the road,” said senior author Benjamin S. Bleier, M.D., of the department of otolaryngology at Mass. Eye and Ear/Harvard Medical School.
The nasal mucosal grafting solution. Researchers delivered glial derived neurotrophic factor (GDNF), a therapeutic protein in testing for treating Parkinson’s disease, to the brains of mice. They showed that their delivery method was equivalent to direct injection of GDNF, which has been shown to delay and even reverse disease progression of Parkinson’s disease in pre-clinical models.
Once they have finished the treatment, they use adjacent nasal lining to rebuild the hole in a permanent and safe way. Nasal mucosal grafting is a technique regularly used in the ENT (ear, nose, and throat) field to reconstruct the barrier around the brain after surgery to the skull base. ENT surgeons commonly use endoscopic approaches to remove brain tumors through the nose by making a window through the blood-brain barrier to access the brain.
The safety and efficacy of these methods have been well established through long-term clinical outcomes studies in the field, with the nasal lining protecting the brain from infection just as the blood brain barrier has done.
By functionally replacing a section of the blood-brain barrier with nasal mucosa, which is more than 1,000 times more permeable than the native barrier, surgeons could create a “screen door” to allow for drug delivery to the brain and central nervous system.
The technique has the potential to benefit a large population of patients with neurodegenerative disorders, where there is still a specific unmet need for blood-brain-penetrating therapeutic delivery strategies.