The development of nanoparticle-based systems for diagnostic and therapeutic purposes is one of the perspective areas in modern biomedicine. From the number of different nanomaterials, magnetic nanoparticles in particular magnetite nanoparticles (MNPs) are certainly the most promising material for biomedical applications, including magnetic-resonance imaging (MRI), hyperthermia, cell-labeling and others [1]. Shape- and size-controlled synthesis of nanoparticles has become a recent focus, because different shapes of particles can introduce novel magnetic and electric properties, which affect the parameters required for biomedical applications, such as MRI and hyperthermia. MNPs with strongly marked anisotropy represent a special interest for biomedical applications. In particular colloidal clusters with controlled size and shape have been an area of great interest for researchers coming from a wide range of disciplines [2]. The controlled assembly of initial small magnetic nanoparticles into cluster structures with defined shape and size opens horizons for materials which combines properties of individual nanocrystals as well as collective properties due to interactions between the single units.
In this work one-pot method for producing magnetic nanocrystal clusters was used. All samples were obtained by thermal decomposition of iron precursor in high-boiling organic solvents in the presence of different organic acids. The results show that the organic acids can directly affect the final shape and size of nanoclusters through specific absorbance onto surface of magnetite nanocrystals. Thus, nanoclusters with spherical, cubic and flower-like shape were obtained. To confirm structure of obtained nanoclusters physicochemical investigations such as transmission electron microscopy, X-ray diffraction analysis, Mössbauer spectroscopy, magnetic measurements, thermogravimetric analysis, magnetic resonance imaging and others were performed. For determination of T2-relaxivity values as well as in vitro and in vivo testing nanoclusters were modified by polyethylene glycol derivative. All obtained magnetite nanoclusters have very high magnetic saturation and T2-relaxivity values. Moreover they can be promising nanomaterials for MRI and hyperthermia.
This work has been financially supported by Ministry of Education and Science of the Russian Federation (14.607.21.0132, RFMEFI60715X0132).
[1] L.H. Reddy et.al. Chem. Rev. 112, 5818 – 5878 (2012)
[2] A. Kostopoulou, Nanotechnol. Rev. 4(6), 595–624 (2015)
Targeted drug delivery and nanocarriers , Nanomedicine for cancer diagnosis & therapy , Nano-Imaging for diagnosis, therapy and delivery
