Preparation Of Hydrophilic Magnetic Nanocomposite Particles Rhenium Labeling Experiments

The hydrophilic carboxylated magnetic nanoparticles were prepared via different soft chemical methods and the better one with greatest properties was chosen by characterized for later functionalized with biomaterials and then applied in the radiolabeling with no-radioactive rhenium. The details were described as follows:Firstly, the secondary cluster magnetic nanoparticles were prepared by hydrothermal synthesis and the monodisperse magnetic nanoparticles were prepared via thermal decomposition synthesis which both used poly(acrylic acid) as the stabilizer and surface modifier while chosing different iron source. The synthesized products were characterized by TEM, FTIR, TG, XRD, VSM and so on. The results showed that better nanopartics were prepared the thermal decomposition synthesis with average size of less than 10 nm, the magnetic content of 71% and the saturation magnetization of 36.8 emu/g which would be used for later functionalion. Then the formation mechanism of carboxylated Fe3O4 magnetic nanopartics synthesis was analysed in detail including the NP's growing trend in the hydrothermal synthesis and NP's nucleation and growth in thermal decomposition synthesis.Secondly, biomaterials (lysine, BSA and folate) were grafting on to the surface of carboxylated magnetic nanoparticls via the water-soluble EDC/NHS mediated coupling reactions. The synthesized products were characterized by TEM, FTIR, TG, UV, VSM to ensure the biomaterials had been successfully coated. The results showed that folate grafted on to the magnetic nanoparticles with the average diameter of 20 nm and saturation magnetization of 29 emu/g. Subsequently, the formation mechanism of carboxylated magnetic nanoparticles with acylation and amidation reaction was explained in detail which took the coupling with lysine as example.Finally, the basic labeling study based on non-radioactive rhenium was carried out with mixing synthesized FA@MNPs with NaReO4. Thus fac-[Re(CO)3(H2O)3]+ was prepared and was chelated with nanoparticles at the same time and the products were purified with NdFeB magnets. The black magnetic nanoparticles were characterized by XPS to ensure the existence of rhenium element with the formation mechanism of rhenium carbonyl compound. The element researches offered the theoretical basis and experimental foundation for the follow-up successful labeling of radioactive nuclear 188Re on the magnetic nanoparticles.