Effects of Gold Nanospheres and Nanocubes on Amyloid-β Peptide Fibrillation

Direct exposure or intake of engineered nanoparticles (ENPs) to the human body will trigger a series of complicated biological consequences. Especially, ENPs could either up- or downregulate peptide fibrillation, which is associated with various degenerative diseases like Alzheimer’s and Parkinson’s diseases. This work reports the effects of gold nanoparticles (AuNPs) with different shapes on the aggregation of an amyloid-β peptide (Aβ(1–40)) involved in Alzheimer’s disease. Two kinds of AuNPs were investigated, i.e., gold nanospheres (AuNSs, ∼20 nm in diameter) and gold nanocubes (AuNCs, ∼20 nm in edge length). It was found that AuNPs play a catalytic role in peptide nucleation through interfacial adsorption of Aβ(1–40). AuNSs with hybrid facets have higher affinity to Aβ(1–40) because of the higher degree of surface atomic unsaturation than the {100}-faceted AuNCs. Therefore, AuNSs exert a more significant acceleration effect on the fibrillation process of Aβ(1–40) than AuNCs. Besides, a shape-dependent...