Scientists at the University of Oxford in the UK have developed a new method for delivering complex drugs directly to the brain.

In a study published in Nature Biotechnology, researchers said that the new method is a necessary step for treating Alzheimer’s, Parkinson’s, motor neurone diseases and muscular dystrophy.

In an experiment involving mice, scientists switched off the BACE1 gene implicated in Alzheimer’s disease by intravenously injecting exosomes, which are able to ferry a drug across the normally impermeable blood-brain barrier to the brain.

This resulted in a 60% decrease in the gene’s activity.

Dr Matthew Wood of the Department of Physiology, Anatomy and Genetics at the University of Oxford said, “These are dramatic and exciting results. It’s the first time new ‘biological’ medicines have been delivered effectively across the blood-brain barrier to the brain.”

One of the medical challenges with diseases of the brain is getting any treatment to cross the blood-brain barrier, which protects the brain by preventing bacteria from crossing over from the blood, while letting oxygen through.

However, this has proved a problem for medicine, as drugs can also be blocked by the barrier.

“The major barrier for these drugs is delivery,” added Dr Wood. “This problem becomes even greater when you want to reach the brain.”

Delivering any such type of therapy to the brain would have to involve neurosurgery.