METHOD FOR PRODUCING RADIOLABELLED CALCIUM CARBONATE PARTICLES USING TETRAXETAN AS CHELATING AGENT Russian patent published in 2023 - IPC A61K9/14 A61K51/02 A61K51/08 A61K51/12 

FIELD: biotechnology.

SUBSTANCE: present invention relates to a method for producing calcium carbonate particles with a radioisotope included in the structure, during which a solution is prepared with human serum albumin (HSA) and the chelating agent tetraxetan (DOTA), after which the resulting solution is radiolabelled with the isotope and the resulting radiolabelled biomolecules are included in the carbonate structure calcium, characterized in that before adding to the solution, human serum albumin weighing 20 g is purified by mixing with 200 mcl of deionized water and 100 mcl of a saturated solution of diethylenetriaminepentaacetic acid, followed by incubation with stirring and heating to 37°C for 30 min, after which human serum albumin is purified from diethylenetriaminepentaacetic acid on a 0.5 ml regenerated cellulose ultrafiltration cell for 20 min at 10 rpm and washed 3 times with a 0.1 M aqueous solution of 4-( 2-hydroxyethyl)-1-piperazinethanesulfonic acid with pH 8.5, and then human serum albumin purified from impurities is diluted with a 0.1 M aqueous solution of 4-(2-hydroxyethyl)-1-piperazinethanesulfonic acid to a volume of 1.8 ml and 3 mg of chelating agent is added DOTA in 75 mcl of 99.5% ethanol and 30 mcl of 2 M aqueous solution of Na₂CO₃, and the modification is carried out at 37°C for 30 minutes and at 4°C for 24 hours, and the resulting modified DOTA-HSA solution on an ultrafiltration cell made of regenerated cellulose with a cell of 0.5 ml for 20 minutes at 10 rpm and washed 3 times with a 0.05 M aqueous solution of NH₄AC with pH 7.5, after which the purified DOTA-HSA solution is diluted with a 0.05 M aqueous solution of NH₄AC with pH 7.5 to a concentration of 3 mg/ml, after which the resulting solution is labelled with the radioisotope ⁶⁸Ga, ^l77Lu or ²²⁵Ac, and then the resulting radiolabelled biomolecules are included in the structure of calcium carbonate particles by adding the resulting solution to an aqueous solution of calcium carbonate, stirring at 1000 rpm for 20 minutes until a precipitate forms and washed 1 time with a 95% ethanol solution and 2-3 times with deionized water, after which the surface of the resulting calcium carbonate particles with a radioisotope included in the structure is sequentially covered with 1 ml of an aqueous solution of human serum albumin at a concentration of 6 mg/ml, followed by washing with 1 ml of water and centrifugation, after which the procedure is repeated 6-7 times from the moment the surface of the resulting calcium carbonate particles with the radioisotope included in the structure is covered with solutions until a stable polymer shell is formed, including at least 7 layers.

EFFECT: making radiolabelled calcium carbonate particles suitable for delivering a combination of biologically active substances and radioisotopes to the site of interest.

1 cl, 8 ex