Noninvasive MRI-SERS imaging in living mice using an innately bimodal nanomaterial

ACS Nano. 2011 Feb 22;5(2):1056-66. doi: 10.1021/nn102587h. Epub 2010 Dec 31.

Abstract

We report a novel nanomaterial (AuMN-DTTC) that can be used as a bimodal contrast agent for in vivo magnetic resonance imaging (MRI) and Raman spectroscopy. The probe consists of MRI-active superparamagnetic iron oxide nanoparticles, stably complexed with gold nanostructures. The gold component serves as a substrate for a Raman active dye molecule to generate a surface-enhanced Raman scattering (SERS) effect. The synthesized probe produces T2 weighted contrast and can be used as a SERS active material both in silico (in aqueous solution) and in vivo. A quantitative assessment of T2 relaxation times was obtained using multiecho MRI analysis. The T2 relaxation times of AuMN-DTTC and MN (dextran-coated iron oxide nanoparticles) were 29.23 + 1.45 and 31.58 + 1.7 ms, respectively. The SERS signature of AuMN-DTTC revealed peaks at 508, 629, 782, 844, 1080, 1108, 1135, and 1242 cm(-1). Intramuscular administration of the probe resulted in a decrease of the T2 relaxation time of muscle from 33.4 + 2.5 to 20.3 + 2.2 ms. SERS peaks were observed at 508, 629, 782, 844, 1080, 1108, 1135, and 1242 cm(-1), consistent with the in silico results. Our studies illustrate for the first time the design and in vivo application of a contrast agent, whose component modalities include MRI and SERS. The value of this agent lies in its innately bimodal nature and its application in vivo for molecular imaging applications.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cattle
  • Contrast Media
  • Dextrans / chemistry
  • Drug Stability
  • Female
  • Ferric Compounds / chemistry
  • Gold / chemistry
  • Magnetic Resonance Imaging / methods*
  • Mice
  • Nanostructures* / chemistry
  • Salts / chemistry
  • Spectrum Analysis, Raman / methods*
  • Surface Properties

Substances

  • Contrast Media
  • Dextrans
  • Ferric Compounds
  • Salts
  • ferric oxide
  • Gold