Probing the Aggregation and Immune Response of Human Islet Amyloid Polypeptides with Ligand-Stabilized Gold Nanoparticles.

The use of nanomaterials has recently become an emerging strategy against protein amyloidosis associated with a range of metabolic and brain diseases. To facilitate research in this area, here we first demonstrated the use of hyperspectral imaging (HSI) and COMSOL simulations for reporting the aggregation of human islet amyloid polypeptides (IAPPs), a hallmark of type 2 diabetes, as well as the physical interactions between the peptide and gold nanoparticles (AuNPs) grafted with citrate and poly(ethylene glycol) (PEG400 and PEG3000). We found a distinct anticorrelation between increased IAPP aggregation and decreased spectral red shifts incurred in the AuNP plasmonic resonance. Moreover, Jurkat cells exposed to IAPP and AuNPs were characterized by quantifying their cytokine secretions with a localized surface plasmon resonance (LSPR) immunoassay, where a peak response was registered for the most toxic IAPP oligomers and most suppressed by citrate-coated AuNPs. This study demonstrated the potential of using HSI and LSPR as two new platforms for the facile examination of protein aggregation and their induced immune response associated with amyloid diseases.