Amyloid-β Aggregation with Gold Nanoparticles on Brain Lipid Bilayer

Understanding and manipulating amyloid- (A) aggregation provide key knowledge and means for the diagnosis and cure of Alzheimer's disease (AD) and the applications of A-based aggregation systems. Here, we studied the formation of various A aggregate structures with gold nanoparticles (AuNPs) and brain total lipid extract-based supported lipid bilayer (brain SLB). The roles of AuNPs and brain SLB in forming A aggregates were studied in real time, and the structural details of A aggregates were monitored and analyzed with the dark-field imaging of plasmonic AuNPs that allows for long-term in situ imaging of A aggregates with great structural details without further labeling. It was shown that the fluid brain SLB platform provides the binding sites for A and drives the fast and efficient formation of A aggregate structures and, importantly, large A plaque structures (>15 m in diameter), a hallmark for AD, were formed without going through fibril structures when A peptides were co-incubated with AuNPs on the brain SLB. The dark-field scattering and circular dichroism-correlation data suggest that AuNPs were heavily involved with A aggregation on the brain SLB and less -helix, less -sheet and more random coil structures were found in large plaque-like A aggregates.