An investigation on the effect of β-CD modified Fe₃O₄ magnetic nanoparticles on aggregation of amyloid b peptide (25-35)

Abstract

In this study, β-cyclodextrin (β-CD)-functionalised Fe₃O₄ composite nanoparticles with core–shell structures were fabricated via carbodiimide activation, which were employed to interact with amyloid b (25–35) peptides (_Aβ25–35). The functionalised magnetic core–shell nanoparticles (MNPs) were characterised by Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy, Thermogravimetric analysis (TGA) and X-ray Diffraction, which verified that β-CD was successfully grafted on the surface of Fe₃O₄ MNPs. The effect of β-CD grafted on the Fe₃O₄ MNPs on the aggregation of amyloid-β-(25–35) peptides were investigated by atomic force microscopy (AFM) and Thioflavin T fluorescence measurements. The result showed that, without functionalized MNPs, the amyloid (25–35) peptides aggregated gradually from monomers and oligomers to long fibrils with the incubation time. In comparison, modified MNPs dramatically inhibited fibrilization and further aggregation. This study may contribute to the development of new diagnostic and therapeutic strategies against amyloid-related diseases.

Keywords:

• Alzheimer's disease
• Fibrilization
• Aggregation
• β-CD–Fe₃O₄ MNPs
• Core–shell structures