Characterization and influence of superparamagnetic iron oxide nanoparticles on magnetic signal of magnetic labeled tumor cells in vitro / 中国组织工程研究

ABSTRACT

BACKGROUND: superparamagnetic ferric oxide nanoparticle exhibits small diameter, good water solubility, histocompatibility, superparamagnetism and surface area effect, allowing the application in nuclear magnetic resonance and biomacromolecule as carriers. OBJECTIVE: To construct superparamagnetic iron oxide nanoparticles coated by dextran (DCIONP), determine its physical and magnetic properties and evaluate the magnetic properties of tumor cells labeled by DCIONP in vitro. METHODS: The DCIONP was obtained by means of classical coprecipitation in dextran solution. Its size was determined by the transmission electron microscopy, and the crystal formation in DCIONP was measured by X-ray diffraction analysis. T2 values as well as relaxation rate were evaluated with a 1.5T MR system. After ostecsarcoma cell line MG63, hepatocellular carcinoma cell line HGP2 and rat bone marrow-derived mesenchymal cells were labeled by DCIONP in vitro, the perls blue staining and the transmission electron microscopy were performed to observe intracellular iron. In addition, the change of magnetic signal intensity was measured by 1.5T MR. RESULTS AND CONCLUSION: The iron size was 10 nm and the formation of Fe_3O_4 crystal in DCIONP was confirmed by X-ray diffraction analysis. These nanoparticles possessed some characteristic of superparamagnetic and showed the spin-spin relaxation rate of 3.936×10~6 mol/s. After three kinds of cells were labeled by DCIONP, the nanoparticles were mainly located in nucleus, and partially in cytoplasm confirmed. The spin-spin relaxations were shortened gradually compared with increasing labeled cells. Obvious magnetic attenuation was measured at 2×10~9/L and 2×10~(10)/L labeled cells. Results show that the prepared nanoparticle with stable physical and magnetic prosperities was developed, and it is able to product characteristic magnetic attenuation on the magnetic labeled tumor cells by 1.5T MR.