DNA surface modified gadolinium phosphate nanoparticles as MRI contrast agents

Bioconjug Chem. 2012 May 16;23(5):951-7. doi: 10.1021/bc200553h. Epub 2012 Apr 23.

Abstract

Oligonucleotide modified gadolinium phosphate nanoparticles have been prepared and their magnetic resonance relaxivity properties measured. Nanoparticles of GdPO4·H2O were synthesized in a water/oil microemulsion using IGEPAL CO-520 as surfactant, resulting in 50 to 100 nm particles that are highly dispersible and stable in water. Using surface modification chemistry previously established for zirconium phosphonate surfaces, the particles are directly modified with 5'-phosphate terminated oligonucleotides, and the specific interaction of the divalent phosphate with Gd(3+) sites at the surface is demonstrated. The ability of the modified nanoparticles to act as MRI contrast agents was determined by performing MR relaxivity measurements at 14.1 T. Solutions of nanopure water, Feridex, and Omniscan (FDA approved contrast agents) in 0.25% agarose were used for comparison and control purposes. MRI data confirm that GdPO4·H2O nanoparticles have relaxivities (r1, r2) comparable to those of commercially available contrast agents. In addition, the data suggest that biofunctionalization of the surface of the nanoparticles does not prevent their function as MRI contrast agents.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Contrast Media / chemistry*
  • DNA / chemistry*
  • Gadolinium / chemistry*
  • Magnetic Resonance Imaging
  • Nanoparticles / chemistry*
  • Nanoparticles / ultrastructure
  • Oligonucleotides / chemistry
  • Phosphates / chemistry*
  • Surface Properties

Substances

  • Contrast Media
  • Oligonucleotides
  • Phosphates
  • DNA
  • Gadolinium