ИСТИНА

The continued development of multimodal medical imaging creates demand for contrast agents (CAs) that can be used with multiple imaging techniques. An example of such CAs are Gd-based materials that can be used in magnetic resonance imaging (MRI) and computed tomography (CT), including photon-counting CT. A type of Gd-based material of special interest is nanoparticles with a core-shell structure consisting of a Gd-containing core and a shell formed by amorphous SiO2 with a surface modified with functional groups. The purpose of this work was to produce particles with a core-shell structure Gd2O3@SiO2 and prove their structure for subsequent use as contrast agents for computed tomography and MRI. Gd2O3 nanoparticles were produced by precipitation of Gd2(C2O4)3.10H2O with subsequent decomposition at 750 °C in an air atmosphere. The particle size, according to scanning electron microscopy (SEM), was 200-500 nm. The particle size in an aqueous suspension, measured by the method of optical scattering of particles suspended in water, was 5-10 μm, which probably corresponds to the size of the associates. Particles with a core-shell structure were produced by treating Gd2O3 with (EtO)3SiC3H6NH2 (ɣ-APTES) and then with H2O vapors in a fluidized bed reactor. In this case, the treatment time with ɣ-APTES was varied from 5 to 30 min, and the temperature of the reactor working zone was varied from 150 to 250 °C.