Title

Photothermal ablation of amyloid aggregates by gold nanoparticles

Authors

Authors

R. C. Triulzi; Q. Dai; J. H. Zou; R. M. Leblanc; Q. Gu; J. Orbulescu;Q. Huo

Comments

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Abbreviated Journal Title

Colloid Surf. B-Biointerfaces

Keywords

Au nanoparticle; amyloid; aggregation; monofunctionalization; photothermal; ablation; PHASE SYNTHESIS APPROACH; BETA-SHEET BREAKERS; ALZHEIMERS-DISEASE; PROTEIN; LASER; DYNAMICS; THERAPY; PICOSECOND; PARTICLES; RESONANCE; Biophysics; Chemistry, Physical; Materials Science, Biomaterials

Abstract

Amyloid peptide (A beta) is found in the brain and blood of both healthy and diseased individuals alike. However, upon secondary structure transformation to a beta-sheet dominated conformation, the protein aggregates. These aggregates accumulate to form neuritic plaques that are implicated in the pathogenesis of Alzheimer's disease. Gold nanoparticles are excellent photon-thermal energy converters. The extinction coefficient of the surface plasmon band of gold nanoparticles is very large when compared to typical organic dyes. In this study, gold nanoparticle-A beta conjugates were prepared and the photothermal ablation of amyloid peptide aggregates by laser irradiation was studied. Monofunctional gold nanoparticles were prepared using a recently reported solid phase modification method and then coupled to fragments of A beta peptide, namely A beta(31-35) and A beta(25-35). The conjugates were then mixed with A beta fragments in solution. The aggregated peptide formation was studied by a series of spectroscopic and microscopic techniques. The peptide aggregates were then irradiated by a continuous laser. With gold nanoparticle-A beta conjugates present the aggregates were destroyed by photothermal ablation. Gold nanoparticles without A beta conjugation were not incorporated into the aggregates and when irradiated did not result in photothermal ablation. With gold nanoparticle-A beta conjugates the ablation was selective to the site of irradiation and minimal damage was observed as a result of thermal diffusion. In addition to the application of photoablation to a protein-based sample the nanoparticles and the chemistry involved provide an easily monofunctionalized photothermal material for the biological conjugation. (C) 2008 Elsevier B.V. All rights reserved.

Journal Title

Colloids and Surfaces B-Biointerfaces

Volume

63

Issue/Number

2

Publication Date

1-1-2008

Document Type

Article

Language

English

First Page

200

Last Page

208

WOS Identifier

WOS:000256102800006

ISSN

0927-7765

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