Dentine collagen cross-linking using tiopronin-protected Au/EDC nanoparticles formulations

摘要

Objective. The aim of this study was to investigate EDC-assisted collagen crosslinking effect with different concentrations of tiopronin-protected gold (TPAu) nanoparticles on demineralized dentine.Methods. TPAu nanoparticles were fabricated from 0.31-g tetrachloroauric acid and 0.38g of N-(2-mercaptopropionyl) glycine (2.4-mmol). Then co-dissolved using 35-mL of 6:1 methanol/acetic acid and mixed using NaBH4. EDC (0.3-M) was conjugated to TPAu nanoparticles at TPAU/EDC-0.25:1, and TPAU/EDC-0.5:1 treatment formulations ratios. Dentin specimens treated with 0.3-M EDC solution alone or left untreated were used as control. Nanoparticles formulations were characterized in term of particles morphology and size, Zeta potential, thermogravimetric analysis and small-angle X-ray scattering. Dentin substrates were characterized in term of TEM investigation, dentin proteases characterization, hydroxyproline liberation, elastic modulus measurement, Raman analysis and confocal microscopy viewing.Results. TEM evaluation of tiopronin protected gold nanoparticles dispersion revealed nanoclusters formations in both groups. However, based on our TEM measurements, the particlesize was ranging from 20 to 50 nm with spherical core-shape which were almost similar for both TPAu/EDC ratios (0.5:1 and 0.25:1). Zeta potential measurements indicate negative nanoparticles surface charge. SAXS profiles for both formulations, suggest a typical profile for uni-lamellar nanoparticles. Superior dentin collagen cross-linking effect was found with the TPAu/EDC nanoparticles formulations compared to the control and EDC treated groups.Significance. Cross-linking of dentin collagen using TPAu coupled with EDC through TPAu/EDC nanoparticles formulations is of potential significance in improving the biodegradation resistance, proteases inhibition, mechanical and structural stability of demineralized dentin substrates. In addition, the cross-linking effect is dependent on TPAu/EDC ratio, whereas higher cross-linking effect was found at TPAu/EDC ratio of 0.5:1. (C) 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.