Mössbauer spectroscopy and proton relaxometry study of magnetite nanoparticles designed for preparing diagnostic contrast media

Abstract

Mössbauer spectroscopy, proton relaxometry, and transmission electron microscopy are used to study magnetite nanoparticles designed for creating diagnostic contrast media. Superparamagnetic magnetite nanoparticles with a size of 5-7 nm and blocking temperature of T b = 50 K are examined as a component of diagnostic contrast media with relaxation times T 1 and T 2 capable of circulating in the bloodstream for a long time. Larger ferrimagnetic nanoparticles (30-40 nm) can be concentrated in pathological tissues by applying an external magnetic field, thereby providing a means for hyperthermia.

Investigation of Aggregation and Disaggregation of Self-Assembling Nano-Sized Clusters Consisting of Individual Iron Oxide Nanoparticles upon Interaction with HEWL Protein Molecules

“…Trisodium citrate-coated iron oxide nanoparticles (TSC-IONPs)-Fe 3 O 4 (FeO•Fe 2 O 3 )were obtained by chemical deposition of oxide with ammonium hydrate from an aqueous solution of a mixture of trivalent and divalent iron chloride salts, based on the technique described in previous publications [19,20].…”

“…The initial mass ratio of trivalent and divalent iron chlorides was chosen as 2:1, with a slight shift in the concentration ratio compared to the strict molar ratio [20]. The FeCl 2 •4H 2 O in a mass of 3 g was dissolved in 12.5 mL of water and 6 g of FeCl 3 •6H 2 O in 12.5 mL of water; each solution was intensively mixed separately for 15 min, at a temperature of 27 • C. The combined solution was stirred for 1 h at a selected speed of 800 rpm.…”

“…The optimal way to control the formation of nanoparticles is to analyze the dynamics of changes in the pH of the solution. However, the determining role is played not by the pH value itself at a certain stage of synthesis, but by the dynamics of its change [20].…”

Magneto-optical properties of nanoparticle dispersions based on Fe-=SUB=-3-=/SUB=-O-=SUB=-4-=/SUB=-, obtained by pulse laser ablation in a liquid

“…The ability of oriented and structured magnetic fluids to change absorption in a wide range of the spectrum is of great interest, which is used to control the parameters of electromagnetic radiation in the THz area of the spectrum [3][4][5][6]. Another very wide and promising area of application of magnetic fluids is medicine, where such materials are used for magnetic separation, magnetic hyperthermia, magnetic targeted drug delivery [7], magnetic resonance imaging and a number of other applications [8][9][10]. The prospect of using magnetic fluids with NPs is due to the small size of the particles, high penetrating power, and the opportunity of remote handling with the help of a magnetic field.…”