Optimal preparation procedure and quality evaluation of the superparamagnetic iron oxide coated by dextran / 中华核医学与分子影像杂志

ABSTRACT

Objective To determine the optimal procedure for preparation of the SPIO nanoparticles modified by dextran polylysine,and to evaluate the quality of this product.Methods The optimal preparation procedure of four factors (solution pH value,dextran concentration,reaction temperature and stirring rate) affecting SPIO hydrodynamic size were obtained through orthogonal experiments (3 levels).SPIO nanoparticles were synthesized under an optimum procedure.The shape and hydrodynamic size were detected by transmission electron microscope (TEM) and Malvern Zetasizer respectively.The content of Fe was detected by atomic absorption spectrophotometer,while chemical structures of SPIO nanoparticles were characterized and analyzed by infrared spectroscopy (IR) method.X-ray powder diffraction method was used to identify the ingredients,and the magnetic parameters were measured by vibrating sample magnetometer.Furthermore,experiments with ovarian cancer cells were performed to primarily validate the magnetic property of SPIO nanoparticles.Results The results of the orthogonal experiments showed that the optimum preparation procedure was as follows:dextran concentration of 10 mg/ml,pH 10,reaction temperature of 80 ℃ and stirring rate of 600 r/min.The TEM results showed the SPIO nanoparticles were in spherical shape,homogeneously distributed and uniform in size,and the mean diameter was 7.0 nm.The content of Fe was (12.36±0.08) g/L.The IR results clearly showed that the Fe3O4 was coated by dextran successfully.The Xray powder diffraction method showed that the sample contained Fe3O4 and the magnetism parameters indicated that the sample had superparamagnetism.The experiments with ovarian cancer cells demonstrated that SPIO nanoparticles could enter into the cells and then the cells had certain magnetic properties.Conclusions The SPIO nanoparticles synthesized under the optimal procedure are stable,small in size,with good dispersion and are feasible to enter into cells for rendering certain magnetic properties.This study has provided a good foundation and potential for further research.