Aggregation of amyloid peptides into fibrils driven by nanoparticles and their curvature effect

Fibrillation of amyloid peptides induces human diseases such as Alzheimer's disease, which has become a huge challenge. Some nanoparticles (NPs) could enhance peptide fibrillation by decreasing the lag time, yet how the size and shape of NPs affect amyloid fibrillation as well as the underlying mechanism remains unclear. Here, we investigated amyloid fibrillation on the surface of spherical NPs and cylindrical nanorods (NRs) of different sizes using coarse-grained Monte Carlo simulations. We focused on the curvature effect of NPs/NRs on the adsorption and fibrillation of peptide chains due to the size/shape difference. As the size of the NPs/NRs increases, the number of assembled peptide chains shows a non-monotonic tendency, and there is an optimal size for the highest adsorption. In most cases, the NRs could adsorb more peptides than the NPs of the same diameter due to the lower curvature. The mechanism beneath these observations was elucidated from a thermodynamic point of view. Our findings could provide a physical basis for the adsorption and fibrillation of amyloid peptides on NPs, and guide the design of future curvature-dependent NP-based amyloid treatment.