title: Investigation of the inhibitory effects of TiO(2) on the β-amyloid peptide aggregation.
abstract: TiO2 thin films are of great interest as biocompatible coatings and also as photocatalytic self-cleaning and antimicrobial coatings. In this work we used β-amyloid as a model for infectious protein to investigate the attachment and photocatalytic degradation. TiO2 films were prepared on stainless steel substrates using magnetron sputtering. The films were characterised before and after exposure to β-amyloid (1-42), using XRD, Raman spectroscopy, XPS and AFM. The TiO2 film was mostly composed of the anatase phase with a relatively high surface roughness. The presence of Raman peaks at 1668cm(-1) and 1263cm(-1), with the XPS spectral feature for nitrogen at 400eV, confirmed the adsorption of amyloid on surface. Following exposure of the β-amyloid contaminated TiO2 to UV-B irradiation a slight shift of amide modes was observed. Furthermore, the amide I spectra show an overall decrease in α-helix content with presence of a minor peak around 1591cm(-1), which is related to tryptophanyl and tyrosinyl radicals, which can lead to conformational change of β-amyloid. The C1s band at 292.2eV suggests the formation of free carboxylic acid. The loss in the crucial structure of β-amyloid leads to reduce the fibril formation, thought to be induced through a photocatalytic process.
authors.affiliation: School of Chemical Science, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland; Nanotechnology Integrated Bioengineering Centre, University of Ulster, Jordanstown, BT37 0QB Belfast, UK. Electronic address: ahmed-m@email.ulster.ac.uk.
authors.forename: Mukhtar H
authors.initials: MH
authors.lastname: Ahmed
authors.affiliation: Nanotechnology Integrated Bioengineering Centre, University of Ulster, Jordanstown, BT37 0QB Belfast, UK.
authors.forename: John A
authors.initials: JA
authors.lastname: Byrne
authors.affiliation: School of Chemical Science, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland.
authors.forename: Tia E
authors.initials: TE
authors.lastname: Keyes
mesh_terms: D000327:Adsorption; D016229:Amyloid beta-Peptides / Q000737:chemistry*; D002384:Catalysis; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D014961:X-Ray Diffraction
chemical_list: D016229:Amyloid beta-Peptides; D020099:Coated Materials, Biocompatible; C009495:titanium dioxide; D014025:Titanium
keywords: Photocatalytic; Raman spectroscopy; TiO(2); XPS; β-Amyloid peptide