Photoacoustic therapy involves the use of carefully modulated laser light to rapidly dump energy into very specific locations in a tissue, where flash heating will destroy the intended target. Work to date involves, for example, delivering carbon nanotubes to cancer cells and then using laser light to explode the nanotubes. Researchers are now considering the potential for forms of photoacoustic therapy to destroy aggregrates of misfolded proteins associated with neurodegenerative disease:
[Researchers] have made a discovery that may lead to the curing of diseases such as Alzheimer's [and] Parkinson's through photo therapy. [It] is possible to distinguish aggregations of the proteins, believed to cause the diseases, from the the well-functioning proteins in the body by using multi-photon laser technique.
If the protein aggregates are removed, the disease is in principle cured. The problem until now has been to detect and remove the aggregates. The researchers now harbor high hopes that photo acoustic therapy, which is already used for tomography, may be used to remove the malfunctioning proteins. Today amyloid protein aggregates are treated with chemicals, both for detection as well as removal. These chemicals are highly toxic and harmful for those treated. With multi photon laser the chemical treatment would be unnecessary. Nor would surgery be necessary for removing of aggregates. Due to this discovery it might, thus, be possible to remove the harmful protein without touching the surrounding tissue.
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. This makes them different from the well-functioning proteins in the body, which can now be shown by multi photon laser technique.
This may be overly optimistic on a few counts: firstly that the amyloid is definitely the disease agent in all cases, versus a secondary effect - though the research community should still work to remove it, as it is an enumerated difference between healthy and diseased tissue. Secondly it may not be as straightforward as hoped to deliver heat via laser only to amyloid without causing secondary damage to delicate nearby structures in neurons and synapses. You might recall that a community-funded attempt to break down liposfuscin through modulated laser light didn't go so well on that count. It proved more challenging than expected to keep the heat and damage constrained to just the lipofuscin. Still, this should just be another technical hurdle to overcome.