Compact zwitterion-coated iron oxide nanoparticles for in vitro and in vivo imaging

We have recently developed compact and water-soluble zwitterionic dopamine sulfonate (ZDS) ligand coated superparamagnetic iron oxide nanoparticles (SPIONs) for use in various biomedical applications. The defining characteristics of ZDS-coated SPIONs are small hydrodynamic diameters, low non-specific interactions with fetal bovine serum, the opportunity for specific labeling, and stability with respect to time, pH, and salinity. We report here on the magnetic characterization of ZDS-coated SPIONs and their in vitro and in vivo performance relative to non-specific interactions with HeLa cells and in mice, respectively. ZDS-coated SPIONs retained the superparamagnetism and saturation magnetization (M[subscript s]) of as-synthesized hydrophobic SPIONs, with M[subscript s] = 74 emu g[superscript −1] [Fe]. Moreover, ZDS-coated SPIONs showed only small non-specific uptake into HeLa cancer cells in vitro and low non-specific binding to serum proteins in vivo in mice.
National Institutes of Health (U.S.) (MIT-Harvard Center for Cancer Nanotechnology Excellence Grant 1U54-CA119349)
National Cancer Institute (U.S.) (Grant R01-CA126642)
Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (W911NF-07-D-0004)
National Science Foundation (U.S.) (Collaborative Research in Chemistry Program CHE-0714189)