METHOD OF PRODUCING MODIFIED GADOLINIUM-DOPED MAGNETITE NANOPARTICLES Russian patent published in 2020 - IPC C01G49/08 B82B3/00 A61K103/34 B82Y40/00 

FIELD: chemistry.

SUBSTANCE: invention relates to inorganic chemistry, specifically to a method of producing modified nanoparticles of gadolinium-doped magnetite. These nanoparticles can be used, for example, as double contrast agents for MRI diagnostics. Method of producing modified nanoparticles of magnetite doped with gadolinium involves mixing an aqueous solution containing a mixture of FeCl₂⋅4H₂O and hydrate of gadolinium chloride, with an aqueous solution of sodium benzoate, adding acetonitrile to the obtained solution, stirring the mixture to form a precipitate, separating the formed precipitate from the supernatant, washing the residue with diethyl ether, drying the residue on air, mixing it with oleylamine, oleic acid and dibenzyl ether, heating the obtained mixture to 110 °C in atmosphere of inert gas with subsequent temperature increase to 310 °C, cooling mixture to room temperature in atmosphere of inert gas, adding alcohol, separation of particles, their redispersion in hexane and treatment of nanoparticles with an organic hydrophilic modifier. Gadolinium chloride hydrate is used GdCl₃⋅6H₂O, metal chlorides are taken in molar ratio FeCl₂⋅4H₂O:GdCl₃⋅6H₂O = 2.5:1.2, mixture heating from 110 °C to 310 °C is carried at rate of 2°/min and the mixture is held at 310 °C for 30 minutes, and the organic hydrophilic modifier used is Pluronic F-127, which is a block copolymer of polyoxyethylene and polyoxypropylene.

EFFECT: technical result consists in increase of saturation magnetization in 1.70 times, relaxation factor r₁ in 1.04 times and relaxation factor r₂ in 1.37 times.

1 cl, 3 ex