Now, an implant to ward off Alzheimer's

A team of scientists has developed an implantable capsule that offers new hope in the quest to prevent Alzheimer's disease.

One of the hypothesized causes of Alzheimer's is the over-accumulation of the protein amyloid beta (Abeta) in different areas of the brain. This results in the deposition of aggregated protein plaques, which are toxic to neurons. One of the most promising ways to fight the plaques is to "tag" the Abeta proteins with antibodies that signal the patient's own immune system to attack and clear them.

To be most effective, this treatment has to be given as early as possible, before the first signs of cognitive decline. But this requires repeated vaccine injections, which can cause side effects. Scientists at École Polytechnique Federale de Lausanne in Switzerland have now solved the problem with an implant that can deliver a steady and safe flow of antibodies to the patient's brain to clear Abeta proteins.

The implant, which works by activating the body's immune system and turning it against the disease, is designed to sit underneath a person's skin, and over time, releases a steady flow of antibodies into the bloodstream.

Those antibodies then cross into the brain, where they target the beta amyloid plaques that are a hallmark of Alzheimer's disease.

Scientists tested the device on genetically engineered mice and discovered that the capsule prevented the plaques from forming.

The discovery could transform the way doctors approach Alzheimer's treatment and prevention, experts hope.

The capsule itself is based on a design from Aebischer's lab published in 2014. It is referred to as a "macroencapsulation device" and it is made of two permeable membranes sealed together with a polypropylene frame. The completed device is 27-mm long, 12-mm wide and 1.2-mm thick, and contains a hydrogel that facilitates cell growth. All the materials used are biocompatible, and the lab specifically used a method that is easily reproducible for large-scale manufacturing.

The study is published in the journal Brain.