Nanoparticles for the diagnosis and possibly treatment of Alzheimer's disease
Alzheimer's disease: diagnosis and treatment
Surprisingly, the diagnostic method also turned out to have therapeutic potential.
Alzheimer's disease affects one in nine people who have reached the age of 65. This is a big problem for the Western world. In addition to the obvious humanistic component, this problem also has an economic one. From an economic point of view, a person who has a neurodegenerative disease in adulthood (and the seventh decade is no longer quite or even not old age in developed countries), from a very experienced specialist and a full–fledged family member turns into a person whom the state and/ or the family must support and who must be carefully looked after in everyday life. It is estimated that in 2014, Alzheimer's disease cost the United States $ 200 billion, and, according to forecasts, in 2050 it will cost more than a trillion. And these are only direct expenses, and not, for example, a wife who is forced to quit her job so that her sick husband does not set fire to the house.
Symptoms of Alzheimer's disease begin to manifest when, at the molecular level, the process of its development has been going on for a long time, when the nerve tissue is already irreversibly damaged. At this point, it is too late to treat anything (perhaps someday they will invent drugs that restore nerve tissue, but there are none yet), the process of developing the disease can only be slowed down, and even then not too much.
At the stage when a person is diagnosed, beta-amyloid plaques can be found in the brain, rather large structures from the beta-amyloid protein that has become insoluble. However, even earlier (sometimes for ten years), oligomers (from the Greek oligos – small) of beta-amyloid appear. They hit synapses in the brain and begin to destroy memories.
This is exactly the stage at which therapy could be very effective, because the nerve tissue is still relatively intact. So far, the only way to detect beta-amyloid oligomers has been spinal fluid puncture. This is an invasive procedure, and it will not be done to all apparently healthy people in a row to make sure that in a dozen years they will not develop Alzheimer's disease.
Magnetic resonance imaging is best suited for non-invasive diagnostics. The problem is that beta-amyloid oligomers themselves are not visible on tomograms, because, firstly, they are too small, and secondly, because the atoms that make up them do not differ much in their electromagnetic properties from the atoms of other molecules. The authors of the work figured out how to make a noticeable difference appear.
To do this, the researchers took antibodies to beta-amyloid and combined them with magnetic nanoparticles. The resulting conjugates were injected into mice in the form of nasal drops. It was assumed that the particles would get into the brain through the olfactory neurons. And so it turned out. The antibodies anchored magnetic particles in the areas of accumulation of beta-amyloid oligomers, and magnetic resonance imaging showed dark spots in these places. Such spots were not observed on tomograms of mice without Alzheimer's disease. Similar results were also shown in experiments with the nervous tissue of people who died from Alzheimer's disease.
Magnetic nanoparticles coated with antibodies to beta-amyloid oligomers (568-NU4, red) and amyloid plaques (ThioS, green) are visible on a slice of the brain of an elderly mouse with an Alzheimer's disease model. The places where the tags are attached to the targets look yellow. A snapshot from an article in Nature Nanotechnology, given in a press release by Northwestern University: New Non-Invasive Method can Detect Alzheimer's Disease Early - VM.In fact, the authors set themselves the task of creating a system for early non-invasive diagnosis of Alzheimer's disease.
They have completed this task. With the ability to track the amount and distribution of beta-amyloid in real time, scientists will be able to more accurately and quickly assess the effectiveness of the drugs they are developing.
But it may turn out that they have exceeded it. It turned out that mice with Alzheimer's disease who were injected with an experimental substance partially lost symptoms of the disease. That is, what was planned as a diagnostic tool turned out to be, to some extent, a medicine.
Portal "Eternal youth" http://vechnayamolodost.ru25.12.2014