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 Fe 3 O 4 and γ‐Fe 2 O 3 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.