In vivo microcomputed tomography visualization of a hepatocellular carcinoma orthotopic model using a contrast based on LaF3:Ce(5 %)Tb(15 %) nanoparticles

Purpose of the study. To investigate the effectiveness of a new contrast agent based on LaF₃:Ce(5 %)Tb(15 %) nanoparticles on a hepatocellular carcinoma orthotopic model.

Materials and methods. The experiment was performed on female BALB/c Nude mice. The subcutaneous model was created by injecting Hep G2 tumor cell culture into the right side of the animals. The orthotopic models were obtained by implanting a fragment of a subcutaneous Hep G2 xenograft into the left lobe of the liver of mice. Colloidal water solutions of LaF₃:Ce(5 %)Tb(15 %) nanoparticles were prepared by dispersing the nanoparticle powder in bidistilled water using an ultrasonic tube for 30 minutes. Two samples with different nanoparticle sizes (13 and 60 nm) were administered to mice intravenously in a volume of 200 μl at a concentration of 40 mg/ml. The assessment of changes in radiopacity of the internal organs of animals was carried out at different points in time (before nanoparticle injection, at 5 min, 30 min, 1 h, 2 h, 4 h, 24 h, 48 h, and 7 days after inlection) using microcomputer tomography on a Quantum GX2 device. On the 7th day of the experiment, animals were euthanized by dislocation of the cervical vertebrae, organs (liver and spleen) were collected and fixed in a 10 % solution of neutral formalin. Sections for histological examination and their staining were made according to the standard method.

Results. Microcomputer tomography (micro-CT) results indicated accumulation of both contrast samples in the spleen and healthy liver tissue within 5 minutes after intravenous injection, maintaining X-ray contrast for the 7-days. However, no specific accumulation of nanoparticles in the tumor was observed. Histological analysis revealed minimal impact on the liver structure and cells, with a more pronounced effect in the spleen.

Conclusion. These findings suggest that LaF₃:Ce(5 %)Tb(15 %) metal nanoparticles can be used in in vivo experiments for liver and spleen visualization after further investigation of their long-term effects.

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