Biofunctionalized Silica Nanoparticles: Standards in Amyloid-ß Oligomer-Based Diagnosis of Alzheimer's Disease.
J Alzheimers Dis
; 54(1): 79-88, 2016 07 27.
Article
em En
| MEDLINE
| ID: mdl-27472876
ABSTRACT
Amyloid-ß (Aß) oligomers represent a promising biomarker for the early diagnosis of Alzheimer's disease (AD). However, state-of-the-art methods for immunodetection of Aß oligomers in body fluids show a large variability and lack a reliable and stable standard that enables the reproducible quantitation of Aß oligomers. At present, the only available standard applied in these assays is based on a random aggregation process of synthetic Aß and has neither a defined size nor a known number of epitopes. In this report, we generated a highly stable standard in the size range of native Aß oligomers that exposes a defined number of epitopes. The standard consists of a silica nanoparticle (SiNaP), which is functionalized with Aß peptides on its surface (Aß-SiNaP). The different steps of Aß-SiNaP synthesis were followed by microscopic, spectroscopic and biochemical analyses. To investigate the performance of Aß-SiNaPs as an appropriate standard in Aß oligomer immunodetection, Aß-SiNaPs were diluted in cerebrospinal fluid and quantified down to a concentration of 10âfM in the sFIDA (surface-based fluorescence intensity distribution analysis) assay. This detection limit corresponds to an Aß concentration of 1.9âng l-1 and lies in the sensitivity range of currently applied diagnostic tools based on Aß oligomer quantitation. Thus, we developed a highly stable and well-characterized standard for the application in Aß oligomer immunodetection assays that finally allows the reproducible quantitation of Aß oligomers down to single molecule level and provides a fundamental improvement for the worldwide standardization process of diagnostic methods in AD research.
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MEDLINE
Assunto principal:
Peptídeos beta-Amiloides
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Nanopartículas
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Doença de Alzheimer
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article