Photothermal ablation of amyloid aggregates by gold nanoparticles
Abbreviated Journal Title
Colloid Surf. B-Biointerfaces
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
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.
Colloids and Surfaces B-Biointerfaces
"Photothermal ablation of amyloid aggregates by gold nanoparticles" (2008). Faculty Bibliography 2000s. 1067.