Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New dye could offer early test for Alzheimer’s

26.08.2005


MIT technique is noninvasive



MIT scientists have developed a new dye that could offer noninvasive early diagnosis of Alzheimer’s disease, a discovery that could aid in monitoring the progression of the disease and in studying the efficacy of new treatments to stop it.
The work will be published in the Aug. 26 issue of Angewandte Chemie.

Today, doctors can only make a definitive diagnosis of Alzheimer’s-currently the fourth-leading cause of death in the United States-through a postmortem autopsy of the brain. "Before you can cure Alzheimer’s, you have to be able to diagnose it and monitor its progress very precisely," said Timothy Swager, leader of the work and a professor in MIT’s Department of Chemistry. "Otherwise it’s hard to know whether a new treatment is working or not."



To that end, Swager and postdoctoral associate Evgueni Nesterov, also from the MIT Department of Chemistry, worked with researchers at Massachusetts General Hospital and the University of Pittsburgh to develop a contrast agent that would first bind to the protein deposits, or plaques, in the brain that cause Alzheimer’s, and then fluoresce when exposed to radiation in the near-infrared range. The new dye could allow direct imaging of Alzheimer’s plaques through a patient’s skull.

Some of the first noninvasive techniques for diagnosing Alzheimer’s involved agents labeled with radioactive elements that could enter the brain and target disease plaque for imaging with positron emission tomography (PET). However, these methods were expensive and limited by the short working lifetime of the labeled agents.

Swager and colleagues developed the new dye, called NIAD-4, through a targeted design process based on a set of specific requirements, including the ability to enter the brain rapidly upon injection, bind to amyloid plaques, absorb and fluoresce radiation in the right spectral range, and provide sharp contrast between the plaques and the surrounding tissue. The compound provided clear visual images of amyloid brain plaques in living mice with specially prepared cranial windows.

To make the technique truly noninvasive, scientists must further refine the dye so it fluoresces at a slightly longer wavelength, closer to the infrared region. Light in the near-IR range can penetrate living tissue well enough to make brain structures visible. Swager likens the effect to the translucence produced when one holds a red laser pointer against the side of a finger.

"This procedure could be done in a chamber with a photodetector and a bunch of lasers, and it would be painless," he said, adding that infrared fluorescence and other optical techniques will lead to a whole new class of noninvasive medical diagnostics. Swager says fluorescing dyes like NIAD-4 could be ready for clinical trials in the near future.

"What we have is a dye that lights up when it binds to amyloids that form in the brains of people with Alzheimer’s. It’s a completely new transduction scheme-a way of translating a physical or chemical event that’s invisible to the naked eye, into a recognizable signal. Further wavelength adjustments in these dyes will allow us to perform in vivo analysis through human tissue."

The new dye was developed as part of a broader effort in sensing technology at MIT’s Institute for Soldier Nanotechnologies. In addition to its applications as a medical diagnostic, Swager says fluorescing dyes like NIAD-4 could work as signals in a wide variety of sensing schemes.

Eve Downing | EurekAlert!
Further information:
http://www.mit.edu

More articles from Health and Medicine:

nachricht World first: Massive thrombosis removed during early pregnancy
20.07.2017 | Universitätsspital Bern

nachricht Therapy of preterm birth in sight?
19.07.2017 | Universitätsspital Bern

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>