New method based on capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) to monitor interaction between nanoparticles and the amyloid-ß peptide.

ABSTRACT

A novel application of capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) was proposed to efficiently detect and monitor the interaction between polymeric nanoparticles and the ß-Amyloid peptide (Aß(1-42)), a biomarker for Alzheimer's Disease (AD), at concentrations close to physiological conditions. The CE-LIF method allowed the interaction between PEGylated poly(alkyl cyanoacrylate) nanoparticles (NPs) and the soluble Aß(1-42) peptide monomers to be highlighted. These results were confirmed by surface plasmon resonance (SPR) and confocal laser scanning microscopy (CLSM). Whereas SPR showed an interaction between the NPs and the Aß(1-42) peptide, CLSM allowed the formation of large aggregates/assemblies at high NP and peptide concentrations to be visualized. All these results suggested that these nanoparticles could bind the Aß(1-42) peptide and influence its aggregation kinetics. Interestingly, the non-PEGylated poly(alkyl cyanoacrylate) NPs did not alter the aggregation kinetics of the Aß(1-42) peptide, thus emphasizing the high level of discrimination of the CE-LIF method with respect to NPs.