Drug delivery system offers fresh hope to Alzheimer’s patients

SCIENTISTS have found a new way to deliver Alzheimer’s drugs directly to the brain, sparking hopes that more effective treatment could be made available to sufferers.

Efforts to treat the disease have been hampered over the last 50 years by the difficulty of administering drugs to the brain to slow or halt its progression.

But a team of University of Oxford researchers has successfully switched off a gene implicated in Alzheimer’s in the brains of mice by exploiting tiny particles naturally released by cells, called exosomes.

The exosomes, injected into the blood, are able to carry a drug across the normally impermeable blood-brain barrier to the brain where it is needed.

It is hoped that the method, if successfully tested in humans, could resolve the difficulty in administering potential new drugs for many neurological diseases including Parkinson’s, motor neurone disease and muscular dystrophy.

But the researchers cautioned that although the results were significant and promising, a number of steps must be taken before this form of drug delivery can be tested in humans.

Lead scientist Dr Matthew Wood of Oxford’s Department of Physiology, Anatomy and Genetics, 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.

“This is the first time this natural system has been exploited for drug delivery.”

“The major barrier for these drugs is delivery,” Dr Wood said. “This problem becomes even greater when you want to reach the brain. The blood-brain barrier — which stops most things in the blood stream from crossing to our brains — is much too great an obstacle.

“We’ve shown that a natural system could be exploited to deliver drugs across the blood-brain barrier. We believe we can use this same technology for Alzheimer’s, motor neurone disease, Parkinson’s and Huntington’s.”

But safety tests would be needed before the exosomes could be tested in humans, he said.

The Alzheimer’s Society welcomed the findings but said more research was needed to see if the method would be effective for Alzheimer’s sufferers.

Dr Susanne Sorensen, head of research at the charity, said: “In this exciting study, researchers may have overcome a major barrier to the delivery of potential new drugs for many neurological diseases including Alzheimer’s.

“The blood-brain barrier protects the brain from harmful chemicals but also makes it difficult for drugs to reach the target cells. If this delivery method proves safe in humans, then we may see more effective drugs being made available for people with Alzheimer’s in the future.”

* The study, partly funded by the Muscular Dystrophy Campaign, is published in Nature Biotechnology