Synthesis, characterisation and potential biomedical applications of magnetic core-shell structures: carbon-, dextran-, SiO2- and ZnO-coated Fe3O4 nanoparticles

Due to the strong effect of nanoparticles' size and surface properties on cellular uptake and bio-distribution, the selection of coating material for magnetic core-shell nanoparticles (CSNPs) is very important. In this study, the effects of four different biocompatible coating materials on the physical properties of Fe3O4 (magnetite) nanoparticles (NPs) for different biomedical applications are investigated and compared. In this regard, magnetite NPs are prepared by a simple co-precipitation method. Then, CSNPs including Fe3O4 as a core and carbon, dextran, ZnO (zincite) and SiO2 (silica) as different shells are synthesised using simple one- or two-step methods. A comprehensive study is carried out on the prepared samples using X-ray diffraction, vibrating sample magnetometry, transmission electron microscopy and Fourier transform infrared spectroscopy analyses. According to the authors' findings, it is suggested that carbon- and dextran-coated magnetite NPs with high M-s have great potential in the application of magnetic resonance imaging contrast agents. Moreover, silica-coated magnetite NPs with high coercivity are potentially suitable candidates for hyperthermia and ZnO-coated Fe3O4 is potentially suitable for photothermal therapy.