An implant to prevent Alzheimer's

March 17, 2016, Ecole Polytechnique Federale de Lausanne
An infographic of how the implanted capsule releases antibodies to the brain. Credit: Patrick Aebischer (EPFL)

In a cutting-edge treatment for Alzheimer's disease, EPFL scientists have developed an implantable capsule that can turn the patient's immune system against the 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 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. EPFL scientists 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 work is published in the journal Brain.

The lab of Patrick Aebischer at EPFL has developed a bioactive containing that have been genetically engineered to produce antibodies against Abeta. The capsule is implanted in the tissue under the skin, and over time the cells produce and release a steady flow of antibodies into the bloodstream, from where they cross over into the brain to target the Abeta plaques.

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 cells inside the capsule are important. Not only must they be able to produce antibodies, but they also have to be compatible with the patient, so as to not trigger the immune system against them, like a transplant can. This is where the capsule's membranes come into play, shielding the cells from being identified and attacked by the immune system. This protection also means that cells from a single donor can be used on multiple patients.

Before going into capsule, the cells are first genetically engineered to produce antibodies that specifically recognize and target Abeta. The cells of choice are taken from muscle tissue, and the permeable membranes let them interact with the surrounding tissue to get all the nutrients and molecules they need.

The researchers tested the device on mice with great success. The mice - a genetic line that is commonly used to simulate Alzheimer's disease - showed dramatic reduction of Abeta plaque load. Indeed, the constant flow of antibodies produced by the capsule over a course of 39 weeks prevented the formation of Abeta plaques in the brain. The treatment also reduced the phosphorylation of the protein tau, another sign of Alzheimer's observed in these mice.

The proof-of-concept work is a landmark. It demonstrates clearly that encapsulated cell implants can be used successfully and safely to deliver to treat Alzheimer's disease and other neurodegenerative disorders that feature defective proteins.

Explore further: Diagnosing Alzheimer's earlier rather than later

More information: Aurélien Lathuilière et al. A subcutaneous cellular implant for passive immunization against amyloid-β reduces brain amyloid and tau pathologies, Brain (2016). DOI: 10.1093/brain/aww036

Related Stories

Diagnosing Alzheimer's earlier rather than later

May 9, 2016
A hallmark of Alzheimer's disease is the appearance of plaques in the brain. The plaques are gradually made up by the aggregation of a small protein called amyloid-beta or "Abeta". Alzheimer's is usually diagnosed late, when ...

Designer protein gives new hope to scientists studying Alzheimer's disease

July 22, 2016
A new protein which will help scientists to understand why nerve cells die in people with Alzheimer's disease has been designed in a University of Sussex laboratory.

Body's immune system may play larger role in Alzheimer's disease than thought

February 23, 2016
Immune cells that normally help us fight off bacterial and viral infections may play a far greater role in Alzheimer's disease than originally thought, according to University of California, Irvine neurobiologists with the ...

Alzheimer's culprit causes memory loss even before brain degeneration

May 29, 2015
The study, published May 29 in the open access Nature Publishing Group journal Scientific Reports, reveals a direct link between the main culprit of Alzheimer's disease and memory loss.

Possible solution for side effect of Alzheimer's immunotherapy treatment

November 5, 2015
It is estimated that 46.8 million people worldwide are living with dementia, with Alzheimer's disease the most common form.

Tau, not amyloid-beta, triggers neuronal death process in Alzheimer's

October 31, 2014
New research points to tau, not amyloid-beta (Abeta) plaque, as the seminal event that spurs neuron death in disorders such as Alzheimer's disease. The finding, which dramatically alters the prevailing theory of Alzheimer's ...

Recommended for you

Does diabetes damage brain health?

December 14, 2018
(HealthDay)—Diabetes has been tied to a number of complications such as kidney disease, but new research has found that older people with type 2 diabetes can also have more difficulties with thinking and memory.

Amyloid pathology transmission in lab mice and historic medical treatments

December 13, 2018
A UCL-led study has confirmed that some vials of a hormone used in discontinued medical treatments contained seeds of a protein implicated in Alzheimer's disease, and are able to seed amyloid pathology in mice.

Study links slowed brainwaves to early signs of dementia

December 13, 2018
To turn back the clock on Alzheimer's disease, many researchers are seeking ways to effectively diagnose the neurodegenerative disorder earlier.

New discoveries predict ability to forecast dementia from single molecule

December 11, 2018
Scientists who recently identified the molecular start of Alzheimer's disease have used that finding to determine that it should be possible to forecast which type of dementia will develop over time—a form of personalized ...

Researchers classify Alzheimer's patients in six subgroups

December 5, 2018
Researchers studying Alzheimer's disease have created an approach to classify patients with Alzheimer's disease, a finding that may open the door for personalized treatments.

Neuroscientists pinpoint genes tied to dementia

December 3, 2018
A UCLA-led research team has identified genetic processes involved in the neurodegeneration that occurs in dementia—an important step on the path toward developing therapies that could slow or halt the course of the disease. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.