|An opening to the brain via the nasal passage--Courtesy of PloS ONE|
Researchers at Harvard and Boston University have developed a surgical technique to surmount one of the trickiest of drug-delivery obstacles--the blood-brain barrier.
Because of the limited capacity of neuropharmaceuticals to cross the blood-brain barrier (BBB), which normally only lets very small molecules get by, scientists have been looking for a way of "tricking" the brain into letting drugs in to allow consistent treatment of diseases such as Parkinson's. Instead of trying to trick the brain, the Boston scientists decided to make themselves a window in the BBB through the nose, creating a direct pathway to the brain.
By using a novel endoscopic method by which surgeons remove brain tumors through the nose without facial incisions, the researchers were able to reach the brain, according to the study in the journal PLoS ONE. But in order to prevent infection or leakage of cerebral fluid, they grafted a nasal mucosal patch over the opening. The graft is permanent and water-tight, but allows therapeutic agents to enter the brain.
The method worked successfully in rat models, but the scientists have had trouble translating it to clinical use in humans, likely because of differences in the olfactory mucosa. But because of its potential to cut down on infection risks from catheters or cannulas that deliver drugs to the brain, researchers are optimistic about the possibilities.
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