Nano Research & Applications

Role of gold nanorods: Inhibition and dissolution of aβ fibrils induced by near IR laser

International Meeting on Advanced Nanomaterials and Nanotechnology
November 07-08, 2017 Singapore

Sudhakar S, Santhosh PB, Mani E,

Indian Institute of Technology Madras, India

Posters & Accepted Abstracts: Nano Res Appl

DOI: 10.21767/2471-9838-C1-006

Abstract

Extracellular plaques of amyloid beta (A�²) fibrils and neurofibrillary tangles are known to be associated with neurological diseases such as Alzheimer's disease. Studies have shown that spherical nanoparticles inhibit the formation of A�² fibrils by intercepting the nucleation and growth pathways of fibrillation. In this report, gold nanorods (AuNRs) are used to inhibit the formation of A�² fibrils and the shape-dependent plasmonic properties of AuNRs are exploited to faciliate faster dissolution of mature A�² fibrils. Negatively charged, lipid (DMPC) stabilized AuNRs inhibit the formation of fibrils due to selective binding to the positevly charged amyloidogenic sequence of A�² protein. The kinetics of inhibition is characterized by thioflavin T (ThT) fluorescence, transmission electronic microscopy (TEM), atomic force microscopy (AFM), and attenuated total reflectance Fourier transform infrared spectroscopy (ATRFTIR). An increase in the aspect ratio of DMPC-AuNR in the range of 2.2-4.2 decreased the fibrils content proportionally. Further, the fibrils content is decreased by increasing the concentration of AuNR for all aspect ratios. As AuNR absorb near-infrared (NIR) light and creates a localized hotspot, NIR laser (800 nm) is applied for 2 min to facilitate the thermal dissolution of mature A�² fibrils. Majority of A�² fibrils are disintegrated into smaller fragments after exposure to NIR in the presence of AuNR. Thus, the DMPC-AuNRs exhibit a dual effect: inhibition of fibrillation and NIR laser facilitated dissolution of mature amyloid fibrils. This study essentially provides guidelines to design efficient nanoparticle-based therapeutics for neurodegenerative diseases.