Synthesis of a colloid solution of silica-coated gold nanoparticles for X-ray imaging applications

  • Yoshio Kobayashi
  • Ryoko Nagasu
  • Kyosuke Shibuya
  • Tomohiko Nakagawa
  • Yohsuke Kubota
  • Kohsuke Gonda
  • Noriaki Ohuchi
Research Paper

DOI: 10.1007/s11051-014-2551-7

Cite this article as:
Kobayashi, Y., Nagasu, R., Shibuya, K. et al. J Nanopart Res (2014) 16: 2551. doi:10.1007/s11051-014-2551-7

Abstract

This work proposes a method for fabricating silica-coated gold (Au) nanoparticles, surface modified with poly(ethylene glycol) (PEG) (Au/SiO2/PEG), with a particle size of 54.8 nm. X-ray imaging of a mouse is performed with the colloid solution. A colloid solution of 17.9 nm Au nanoparticles was prepared by reducing Au ions (III) with sodium citrate in water at 80 °C. The method used for silica-coating the Au nanoparticles was composed of surface-modification of the Au nanoparticles with (3-aminopropyl)-trimethoxysilane (APMS) and a sol–gel process. The sol–gel process was performed in the presence of the surface-modified Au nanoparticles using tetraethylorthosilicate, APMS, water, and sodium hydroxide, in which the formation of silica shells and the introduction of amino groups to the silica-coated particles took place simultaneously (Au/SiO2–NH2). Surface modification of the Au/SiO2–NH2 particles with PEG, or PEGylation of the particle surface, was performed by adding PEG with a functional group that reacted with an amino group in the Au/SiO2–NH2 particle colloid solution. A computed tomography (CT) value of the aqueous colloid solution of Au/SiO2/PEG particles with an actual Au concentration of 0.112 M was as high as 922 ± 12 Hounsfield units, which was higher than that of a commercial X-ray contrast agent with the same iodine concentration. Injecting the aqueous colloid solution of Au/SiO2/PEG particles into a mouse increased the light contrast of tissues. A CT value of the heart rose immediately after the injection, and this rise was confirmed for up to 6 h.

Keywords

Au Silica Core–shell Hydrogen storage Poly(ethylene glycol) X-ray contrast agent 

Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  • Yoshio Kobayashi
    • 1
  • Ryoko Nagasu
    • 1
  • Kyosuke Shibuya
    • 1
  • Tomohiko Nakagawa
    • 2
  • Yohsuke Kubota
    • 2
  • Kohsuke Gonda
    • 2
  • Noriaki Ohuchi
    • 2
  1. 1.Department of Biomolecular Functional Engineering, College of EngineeringIbaraki UniversityHitachiJapan
  2. 2.Division of Surgical Oncology, Graduate School of MedicineTohoku UniversitySendaiJapan

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