Preparation and characterization of superparamagnetic iron oxide nanoparticles stabilized by alginate

Int J Pharm. 2007 Mar 21;333(1-2):177-86. doi: 10.1016/j.ijpharm.2006.10.006. Epub 2006 Oct 7.


SPION with appropriate surface chemistry have been widely used experimentally for numerous in vivo applications. In this study, SPION stabilized by alginate (SPION-alginate) were prepared by a modified coprecipitation method. The structure, size, morphology, magnetic property and relaxivity of the SPION-alginate were characterized systematically by means of XRD, TEM, ESEM, AFM, DLS, SQUID magnetometer and MRI, respectively, and the interaction between alginate and iron oxide (Fe(3)O(4)) was characterized by FT-IR and AFM. The results revealed that typical iron oxide nanoparticles were Fe(3)O(4) with a core diameter of 5-10 nm and SPION-alginate had a hydrodynamic diameter of 193.8-483.2 nm. From the magnetization curve, the Ms of a suspension of SPION-alginate was 40 emu/g, corresponding to 73% of that of solid SPION-alginate. This high Ms may be due to the binding of Fe(3)O(4) nanoparticles to alginate macromolecule strands as visually confirmed by AFM. SPION-alginate of several hundred nanometers was stable in size for 12 months at 4 degrees C. Moreover, T1 relaxivity and T2 relaxivity of SPION-alginate in saline (1.5 T, 20 degrees C) were 7.86+/-0.20 s(-1) mM(-1) and 281.2+/-26.4 s(-1) mM(-1), respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alginates / chemistry*
  • Contrast Media / chemistry*
  • Crystallization
  • Crystallography, X-Ray
  • Ferric Compounds / chemistry*
  • Glucuronic Acid / chemistry
  • Hexuronic Acids / chemistry
  • Magnetic Resonance Imaging / methods
  • Magnetic Resonance Spectroscopy
  • Magnetics
  • Metal Nanoparticles*
  • Microscopy, Atomic Force
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Scattering, Radiation
  • Spectroscopy, Fourier Transform Infrared
  • Technology, Pharmaceutical


  • Alginates
  • Contrast Media
  • Ferric Compounds
  • Hexuronic Acids
  • ferric oxide
  • Glucuronic Acid