Using a multiphoton laser technique, researchers at Chalmers University of Technology (Göteborg, Sweden) and the Polish Wroclaw University of Technology (Wroclaw, Poland) have found it possible to distinguish well-functioning proteins in the body from protein aggregations thought to cause Alzheimer's, Parkinson's, and mad cow diseases.1 These diseases arise when amyloid beta protein are aggregated in large doses so they start to inhibit proper cellular processes. Different proteins create different kinds of amyloids, but they generally have the same structure. The Chalmers researchers found that unlike healthy proteins, amyloid proteins exhibit two-, three-, or multiphoton absorption, depending on the wavelength of illuminating light.
Safe and effective treatment of such diseases has been elusive. In principle, removal of the protein aggregates is curative; the problem thus far has been detection and elimination. The researchers now say that photoacoustic treatment could do the trick. The approach could remove the harmful protein without touching the surrounding, healthy tissue.
The discovery of amyloids' reaction to light also opens up new possibilities to change the nature of materials to which they attach. The researchers say that amyloid aggregates, which they have succeeded in creating artificially, could become the basis for optical nanomaterials and metamaterials.
Hard and rigid as steel, the aggregates are not as heavy and can be tuned for specific purposes. Amyloids are shaped like discs, densely piled upon each other. When a material is merged with these discs, its molecules end up so densely and regularly placed that they can communicate and exchange information—thus the potential to change the material's characteristics.
1. P. Hanczyc, M. Samoc, and B. Norden, Nat. Photon., 7, 969–972 (2013); doi:10.1038/nphoton.2013.282.