METHOD FOR PRODUCING MODIFIED CRYSTALS OF MAGNETITE Russian patent published in 2018 - IPC C30B29/16 C30B30/06 C30B29/60 A61K33/26 A61K41/00 A61K49/06 B82B3/00 B82Y5/00 B82Y30/00 B82Y40/00 

FIELD: chemistry.

SUBSTANCE: invention relates to inorganic chemistry and to a method for producing modified crystals of magnetite Fe₃O₄, containing a fluorescent dye on the surface, which allows visualizing and monitoring their behavior both in a living cell and in a living organism in vivo. Such crystals can be used as drug delivery vehicles and T2-contrast agents. Method for producing modified crystals of magnetite comprises mixing 138 pts.wt. of magnetite crystals and 1 pts.wt. of cholesterol mixture, 1,2-distearoyl-sn-glycero-3-phosphocholine, 1,1'-(2-(4-(2-((2-(bis(2-hydroxydodecyl)amino)ethyl)(2-hydroxydecyl)amino)ethyl)piperazin-1-yl)ethylazanediyl)didodecan-2-ol and 1,2-dimyristoyl-sn-glycerymethoxy(polyethylene glycol)-2000, taken in a weight ratio 15:7:75:3, respectively, initially with 60,000 pts. wt. of chloroform, followed by 82,240 pts. wt. of N-methyl-2-pyrrolidone, treatment of the mixture with ultrasound, removing chloroform and adding water thereto, followed by dialysis of the resulting dispersion of the modified crystals of magnetite against water, wherein crystals of magnetite are used as crystals, wherein the crystals of magnetite are obtained by mixing octadecene with iron(III) oleate or iron(III) acetylacetonate, oleic acid and sodium oleate, heating the mixture to 70 °C and its aging at this temperature for 30 minutes, reheating the mixture in an inert gas atmosphere from 70 °C to 320 °C, holding it at this temperature and cooling the mixture to room temperature, carried out in an inert gas atmosphere, introducing into the isopropanol system, separating the crystals of magnetite, dispersing them in a non-polar high boiling organic solvent selected from the group consisting of dibenzyl ether, octadecene and trioctylamine, in the presence of oleic acid and sodium oleate, heating the resulting dispersion to a temperature of 290–350 °C in an inert gas atmosphere, followed by the dropwise addition of a solution of iron(III) oleate to the heated dispersion, in a non-polar high boiling organic solvent for 1 to 10 hours and cooling the dispersion to room temperature carried out in an inert gas atmosphere, reintroduction into the isopropanol system and separation of magnetite, and further dialysis, the dispersion is concentrated, adding thereto a solution in dimethyl sulfoxide of a fluorescent dye selected from the group consisting of 1,1-dioctadecyl-3,3,3,3-tetramethylindodicarbocyanine, 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbocyanionide and 9-(diethylamino)benzo[a]phenoxazin-5-one, the modified magnetite is separated by centrifugation, then it is washed with a mixture of water and dimethylsulfoxide, then with water. Magnetization of saturation of magnetite in comparison with the prototype increases by 2.09–2.51 times, the velocity value r₂-relaxivity increases by 1.22–1.38 times.

EFFECT: invention allows producing crystals of magnetite with improved magnetic properties.

1 cl, 4 ex