Implant against amyloid plaques
One of the alleged causes of the development of Alzheimer's disease is the excessive accumulation of abnormal beta-amyloid protein in various regions of the brain. This leads to the deposition of aggregated protein plaques in the tissue, which have a toxic effect on neurons. One of the most promising approaches to combating these plaques is to label beta-amyloid with antibodies that attract cells of the patient's own immune system to them. To obtain maximum results, such therapy should be started as early as possible, before the first signs of cognitive function fading. However, this requires repeated administration of the vaccine, which is fraught with side effects. Swiss researchers from the Polytechnic School of Lausanne propose a solution to this problem with the help of an implant that provides a stable and safe supply of antibodies to the patient's brain that help the immune system to cleanse the tissue from beta-amyloid.
The laboratory staff of Professor Patrick Aebischer has developed a bioactive capsule containing genetically modified cells that produce antibodies against beta-amyloid. This capsule is implanted under the skin and for a long time the cells contained in it produce and release antibodies into the bloodstream that penetrate into the brain tissue and label beta-amyloid for destruction by cells of the immune system.
The capsule is based on a prototype developed by the authors in 2014 and called the "macroencapsulation device" (macroencapsulation device). It consists of two permeable membranes soldered together using a polypropylene frame. The length of the entire device, filled with a hydrogel supporting the vital activity of cells, is 27 mm, the width is 12 mm, and the thickness is 1.2 mm. All the materials included in its composition are biocompatible, and the method used for its manufacture can be easily scaled for mass production.
In addition to releasing antibodies into the bloodstream, the capsule performs another important function – it protects the cells contained in it from recognition and destruction by the patient's immune system. The presence of such protection not only eliminates the need to select a donor, but also allows the use of cells from one donor for the treatment of many patients.
The cells enclosed inside the capsule are isolated from muscle tissue, after which they are subjected to genetic modification, which gives them the ability to produce the necessary antibodies. The permeable membrane of the capsule ensures their interaction with the surrounding tissues and the supply of all necessary nutrients and other molecules.
The authors have successfully tested their development on genetically modified mice, traditionally used as a model of Alzheimer's disease. The delivery of antibodies to the brain provided by the capsule for 39 weeks not only reduced the number of existing beta-amyloid plaques and prevented the formation of new ones, but also reduced the level of phosphorylation of tau protein, also associated with Alzheimer's disease.
The results obtained are very revealing. They clearly demonstrate the ability of encapsulated cell implants to efficiently and safely deliver antibodies to the brain tissue for the treatment of Alzheimer's disease and other neurodegenerative diseases characterized by aggregation of abnormal proteins.
Article by Aurélien Lathuilière et al. A subcutaneous cellular implant for passive immunization against amyloid-β reduces brain amyloid and tau pathologies is published in the journal Brain.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on Ecole Polytechnique Fédérale de Lausanne: An implant to prevent Alzheimer's.
18.03.2016