Synthesis and characterization of Fe3O4 nanoparticles with perspectives in biomedical applications

Abstract

Nowadays the use of magnetic nanoparticles (MNP) in medical applications has exceeded expectations. In molecular imaging, MNP based on iron oxide coated with appropriated materials have several applications in vitro and in vivo studies. For applications in nanobiotechnology these MNP must present some characteristics such as size smaller than 100 nanometers, high magnetization values, among others. Therefore the MNP have physical and chemical properties that are specific to certain studies which must be characterized for quality control of the nanostructured material. This study presents the synthesis and characterization of MNP of magnetite (Fe 3 O 4 ) dispersible in water with perspectives in a wide range of biomedical applications. The characterization of the colloidal suspension based on MNP stated that the average diameter is (12.6±0.2) nm determined by Transmission Electron Microscopy where the MNP have the crystalline phase of magnetite (Fe 3 O 4 ) that was identified by Diffraction X-ray and confirmed by Mössbauer Spectroscopy. The blocking temperature of (89±1) K, Fe 3 O 4 MNP property, was determined from magnetic measurements based on the Zero Field Cooled and Field Cooled methods. The hysteresis loops were measured at different temperatures below and above blocking temperature. The magnetometry determined that the MNP showed superparamagnetic behavior confirmed by ferromagnetic resonance.

Importance of the Inter-Electrode Distance for the Electrochemical Synthesis of Magnetite Nanoparticles: Synthesis, Characterization, Computational Modelling, and Cytotoxicity

“…In this larger size cluster, the average Fe oct -Fe oct and Fe oct -O eq bond lengths were found to be 2.94 and 1.91Å, respectively. This is a match with the reported bond distances in the bulk magnetite (2.96 and 2.06 respectively) [67][68][69]. The difference in Fe-O bond length is mostly attributable to the Fe-O-H functions in our cluster rather than the Fe-O-Fe bonds observed in the bulk structure.…”

“…This distinction is important as differing internal geometries play an important role [48,60] in determining the behavior of magnetite-based electronic and spintronic devices. Surface alone vs internal oxidation would also have significant implications for their biomedical application [68], thus a detailed understanding of the presence of different defects in the magnetite (i.e. surface defects and impurities as well as bulk defects) is required [69].…”

Comparative Efficacy of a Biocompatible Citrate-Functionalized Magnetic Fluid Mediating Radiofrequency Hyperthermia and Magnetohyperthermia to Treat Ectopic Ehrlich-Solid-Tumor-Bearing Elderly Mice

“…Although diameters measured by the three different techniques showed different average size values, this was already expected. XDR is mainly used to know the crystalline phase of the nanoparticles (maghemite or magnetite) [48], confirming the composition of maghemite, which is the final step of magnetite oxidation and thus chemically more stable [15,49]. The comparison between XRD, TEM and DLS results confirmed that NPCit have a crystalline core and an amorphous external layer.…”

Studies on Approximation Methods in Calculating the Magnetic Dipolar Interaction Energy, and Its Impact on the Relaxation Time of Magnetic Nanoparticle Systems

“…We assumed periodic boundary conditions on all the sides of the simulation box. lognormal distribution motivated by experimental measurements [37]. Standard deviation for diameter is 0.2d m in our calculations.…”