Currently, there is no cure for Alzheimer’s disease, but a promising and cutting-edge treatment developed by scientists in Switzerland may raise hope for early prevention.
Researchers from the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland reveal how, when implanted in the tissue under the skin, the capsule releases a consistent flow of antibodies that travels to the brain and triggers the patient’s immune system to clear beta-amyloid protein.
The over-accumulation of the protein amyloid beta (amyloid-ß) in different areas of the brain is believed to be one of the hypothesised causes of Alzheimer’s. This leads to the deposition of aggregated protein plaques, which can kill neurons and impair a person’s memory. One of the most ideal ways to deal with these plaques is to “tag” beta-amyloid proteins with antibodies that call on the immune system to attack and get rid of them. Such a treatment, however, has to be administered as early as possible, in the early stages of cognitive decline, to be most effective. This requires repeat injections, which can cause adverse side effects. EPFL scientists addressed the problem with an implant that can deliver a steady and safe flow of antibodies to the patient’s brain to clear amyloid-ß proteins.
How does the implantable capsule work?
The capsule, referred to as a “macroencapsulation device”, is 27 mm in length, 12 mm wide and 1.2 mm thick.
The bioactive capsule contains cells taken from muscle tissue that have been genetically engineered to produce high levels of antibodies that are capable of recognizing and targeting beta-amyloid proteins in the brain.
Once implanted under the skin, the capsule gradually releases the antibodies into the bloodstream. From here, they cross over into the brain to target the amyloid-ß plaques.
The cells inside the capsule play an important role. They must not only be able to produce antibodies, but also be compatible with the patient, in order not to trigger the immune system against them, like a transplant can.
As such, the cells are surrounded by two permeable membranes – fixed together by polypropylene frame – that shield the cells from being identified and attacked by the immune system and enable cells from a single donor to be used on multiple patients. Also, the permeable membranes let the cells get all the nutrients and molecules they need from surrounding tissue.
The authors believe that their findings provide proof of concept that an implantable, antibody-releasing capsule is an effective preventive option for Alzheimer’s and other neurodegenerative diseases that feature defective proteins.