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Sensor for early discovery of Alzheimers

Plaque traces in mouse brain.

Plaque traces in mouse brain.

A new type of sensor developed at LiU can contribute to early diagnosis of serious neurological disease such as Alzheimers.

The biosensor is a specially structured carbon chain, a conjugated polymer, that shifts color to signal pathological change.

The biological function of proteins is determined by their spontaneous ability to fold into three-dimensional structures. In certain diseases, such as Alzheimer's, ALS and Parkinson's, proteins misfold into long threads, amyloid fibers, which degenerate into plaque.

A polymer that interacts with a misfolded protein changes color. The figure above shows plaque (green patches) in the brain of a mouse.

"We discovered this property when we mixed the PTAA polymer with unhealthy insulin, and it suddenly shifted from yellow to red," explains Anna Herland, biotechnician in the Biomolecular and Organic Electronics (Biorgel) research group at the Department of Physics, Chemistry and Biology.

Anna Herland presents her findings in a doctoral thesis. The research was a collaboration that included Dr. Peter Nilsson and Associate Professor Per Hammarström.

The method has been successfully tested on tissue samples from the brain, muscle, pancreas, abdominal fat and kidney. In all cases, the researchers have found that the polymer recolors the plaque. Color change is discernable with the naked eye, but best studied with a spectroscope.

"Applications to reveal traces of incorrectly folded proteins will enable early clinical diagnosis of neurological diseases such as Alzheimer's," Anna Herland continues.

Quality assurance in the drugs industry is another potential use. Impurities caused by protein fibers can appear during manufacture of biosynthetic human insulin and other protein-based substances.

The biosensor will be commercialized through the spin-off firm Biochromix AB, whose CEO is Dr. Peter Åsberg.


2007-10-02




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Last updated: 2009-06-03