The Influence of Extremely Low-Frequency Magnetic Field and Magnetic Nanoparticle on $\text{A}{\boldsymbol \beta }_{\boldsymbol {40}}$ Aggregation In Vitro

Aggregation of β-amyloid (Aβ) is one of the early events in Alzheimer's disease (AD) pathology and is considered to initiate the amyloid cascade. It is presumed that Aβ plaque might coexist with biogenic magnetite. In order to understand the combined effect and mechanism of the biogenic magnetite and Aβ in AD, it is necessary to clarify the role of the magnetite in Aβ aggregation. Due to the magnetic characteristic of the magnetite, it possibly mediates the effect of environmental magnetic field (MF) on Aβ aggregation. Here, we preliminarily characterized the morphology of Aβ₄₀ aggregation coincubated with a magnetic nanoparticle coated with SiO₂ (MNP-SiO₂) in the presence of an external extremely low-frequency MF (ELF MF) exposure. Coincubation with MNP-SiO₂ accelerated Aβ₄₀ aggregation and MF exposure led to more heterogeneous Aβ species. The results indicated that the exposure of ELF MF and MNP-SiO₂ could alter the Aβ₄₀ aggregation. It will provide insights to understand the roles of ELF MF exposure and biogenic magnetite in the AD pathology.