Synthesis of iron‐oxide magnetic nanoparticles coated with dextran of varied molecular mass using a facile ball‐milling method

Abstract

A simple ball-milling method was implemented to prepare dextran-coated superparamagnetic iron oxide nanoparticles (dextran-coated SPIONs, DSPIONs) by coating dextran (molecular mass, M dextran, 10, 40, 70 and 100 kDa) onto nanoparticles, which synthesised with co-precipitation methods. The size, saturation magnetisation and hydrodynamic diameters of the DSPIONs, composed of Fe3O4 and γ-Fe2O3 proved by X-ray diffraction and Raman spectra, were 11–14 nm, 55–65 emu g−1 and 200–300 nm using transmission electron microscope, superconducting-quantum-interference-device magnetometer and dynamic light scattering devices, respectively. The characteristic lines of surface coating were revealed in attenuated-total-reflection Fourier-transform infrared spectra. The saturation magnetisation and surface coating percentage (thermogravimetric analysis) of the ball-milled DSPIONs were independent on M dextran. The results were different from the statistical data from previous studies: DSPIONs using increasing M dextran were accompanied by decreasing saturation magnetisation and increasing surface coating in conventional co-precipitation protocols. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay indicated the ball-milled DSPIONs exhibited low cytotoxicity in human hepatoma (SK-HEP1) cells, and the implementation of Prussian blue staining proved the DSPIONs were able to be uptaken by SK-HEP1. There was no obvious difference between the ball-milled DSPIONs with various M dextran. It demonstrated the ball milling process might be potential for SPION preparation in the biomedical field.