Preparation and characterization of superparamagnetic iron oxide nanoparticles stabilized by alginate

• Published in: International journal of pharmaceutics 2007-03, Vol.333 (1), p.177-186
• Main Authors: Ma, Hui-li, Qi, Xian-rong, Maitani, Yoshie, Nagai, Tsuneji
• Format: Article
• Language: English
• Subjects: Alginate; Alginates - chemistry; Atomic force microscopy (AFM); Biological and medical sciences; Contrast Media - chemistry; Crystallization; Crystallography, X-Ray; Ferric Compounds - chemistry; General pharmacology; Glucuronic Acid - chemistry; Hexuronic Acids - chemistry; Magnetic resonance imaging (MRI); Magnetic Resonance Imaging - methods; Magnetic Resonance Spectroscopy; Magnetics; Magnetometric; Medical sciences; Metal Nanoparticles; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Scattering, Radiation; Spectroscopy, Fourier Transform Infrared; Superparamagnetic iron oxide nanoparticles (SPION); Technology, Pharmaceutical
• ISSN: 0378-5173; 1873-3476
• DOI: 10.1016/j.ijpharm.2006.10.006

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 3O 4) was characterized by FT-IR and AFM. The results revealed that typical iron oxide nanoparticles were Fe 3O 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 3O 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 °C. Moreover, T1 relaxivity and T2 relaxivity of SPION-alginate in saline (1.5 T, 20 °C) were 7.86 ± 0.20 s −1 mM −1 and 281.2 ± 26.4 s −1 mM −1, respectively.