Non-polymer Coated Fe_3O_4 Aqueous Dispersion with NH_3~+-surface Modification as New Magnetite Nanoparticles and Their Biomedical Applications

摘要

Well-dispersed Fe_3O_4 nanoparticles were synthesized using chemical coprecipitation and the addition of organic acid as adherent in an aqueous solution. The resulting iron oxide particles were manipulated as small as 6 nm diameter in size. The nanoparticles exhibit cationic surface mostly decorated with terminal -NH_3~+. The in vitro cytotoxicity test revealed excellent biocompatibility to further explore for their potential in vivo applications. NMR measurements showed significantly reduced water proton relaxation times T_1 and T_2. The MR images of the nanoparticles in water and serum were then investigated using 1.5T clinical MR imager.