Synthesis and characterization of fluorinated magnetic core–shell nanoparticles forinhibition of insulin amyloid fibril formation

Abstract

Maghemite (γ-Fe2O3) magneticnanoparticles of 15.0 ± 2.1 nm are formed by nucleation followed by controlled growth ofmaghemite thin films on gelatin-iron oxide nuclei. Uniform magneticγ-Fe2O3/poly (2,2,3,3,4,4,4-heptafluorobutylacrylate) (γ-Fe2O3/PHFBA) core–shell nanoparticles are prepared by emulsion polymerization of the fluorinated monomer2,2,3,3,4,4,4-heptafluorobutyl acrylate (HFBA) in the presence of the maghemite nanoparticles.The kinetics of the insulin fibrillation process in the absence and in the presence of theγ-Fe2O3/PHFBA core–shell nanoparticles are elucidated. A significant direct slow transition fromα-helixto β-sheets during insulin fibril formation is observed in the presence of theγ-Fe2O3/PHFBA nanoparticles. This is in contradiction to our previous manuscript, which illustrated that theγ-Fe2O3 core nanoparticles do not affect the kinetics of the formation of the insulin fibrils, and toother previous publications that describe acceleration of the fibrillation process by usingvarious types of nanoparticles. These core–shell nanoparticles may therefore be also usefulfor the inhibition of conformational changes of other amyloidogenic proteins that lead toneurodegenerative diseases such as Alzheimer’s, Parkinson’s, Huntington’s, mad cow andprion diseases.