Authors: P.-S. Lai, S.-M. Lai
Affilation: National Chung Hsing University, Taiwan
Pages: 79 - 82
Keywords: iron oxide nanoparticles, clusters, magnetic resonance imaging
Recently, self-assembling clusters of metal nanoparticles have been extensively investigated in various fields. To prepare these clusters, various ionic surfactants, have been employed as stabilizers or emulsifiers to form water-dispersed spherical clusters. However, these ionic surfactants are quite toxic to cells. In this study, well-constructed clusters of iron oxide nanoparticles (IONPs), which were stabilized by the nonionic surfactant d-alpha-tocopheryl poly(ethylene glycol 1000) succinate (TPGS), were easily and successfully prepared by changing the amount of solvent and its evaporation rate in an oil-in-water emulsion system. The optimized clusters were spherical in shape, had a diameter of approximately 97 nm, and can be internalized by KB cells without significant cell toxicity. In addition, these clusters had higher saturation magnetisation and r2 relaxation (253.85 s-1 mM-1) values and better T2-weighted contrast performance (r2/r1 = 20.5) than commercial Resovist®. TPGS-stabilized IONPs clusters were also shown to be an efficient contrast agent for in vivo magnetic resonance imaging, especially in the liver and tumor regions. Iron staining of both tissues confirmed the accumulation of the nanoparticles in both areas. Thus, these clusters, which were prepared with the use of nonionic polymer surfactant, can potentially serve as efficient contrast agents for magnetic resonance applications.