Alzheimer's disease is a chronic neurodegenerative disease that usually starts slowly and gets worse over time and accounts for 60% to 70% of cases of dementia.
The scientists and engineers in Northwestern University have developed a non-invasive MRI (magnetic resonance imaging) probe. The technique pairs a magnetic nanostructure (MNS) with an antibody that seeks out the amyloid beta brain toxins responsible for onset of Alzheimer's disease.
The accumulated toxins have associated magnetic nanostructures and they help show up as dark areas in MRI scans of the brain.
"We have a new brain imaging method that can detect the toxin that leads to Alzheimer's disease," said neuroscientist William L Klein who led the research team along with materials scientist Vinayak P Dravid.
"Using MRI, we can see the toxins attached to neurons in the brain. We expect to use this tool to detect this disease early and to help identify drugs that can effectively eliminate the toxin and improve health," Klein said.
The conventional imaging method is by positron emission tomography using probes that target amyloid fibrils but these fibrils are not closely linked to the development of the disease, said the study.
The new technology is detecting something different from conventional technology: toxic amyloid beta oligomers instead of plaques, which occur at a stage of Alzheimer's when it is useless to give therapeutic intervention. It is believed that Amyloid beta oligomers is the the culprit in the onset of Alzheimer's disease and subsequent memory loss.
In a person suffering from Alzheimer's, the mobile amyloid beta oligomers attack the synapses of neurons, destroying memory and ultimately resulting in neuron death.
"Non-invasive imaging by MRI of amyloid beta oligomers is a giant step forward towards diagnosis of this debilitating disease in its earliest form," said Dravid, the Abraham Harris Professor of Materials Science and Engineering at the McCormick School of Engineering and Applied Science.
"This MRI method could be used to determine how well a new drug is working. If a drug is effective, you would expect the amyloid beta signal to go down," Dravid said.