Negatively Charged Gold Nanoparticles Inhibit Alzheimer's Amyloid‐β Fibrillization, Induce Fibril Dissociation, and Mitigate Neurotoxicity

Amyloids are pathogenic hallmarks in many neurodegenerative diseases such as amyloid‐ β (A β ) fibrils in Alzheimer's disease (AD). Here, the effect of gold nanoparticles (AuNPs) on amyloids is examined using A β as a model system. It is found that bare AuNPs inhibited A β fibrillization to form fragmented fibrils and spherical oligomers. Adding bare AuNPs to preformed A β fibrils results in ragged species where AuNPs bind preferentially to fibrils. Similar results are demonstrated with carboxyl‐ but not amine‐conjugated AuNPs. Co‐incubation of negatively charged AuNPs with A β relieved A β toxicity to neuroblastoma. Overall, it is demonstrated that AuNPs possessing negative surface potential serve as nano‐chaperones to inhibit and redirect A β fibrillization, which could contribute to applications for AD.