Synthesis, research and functionalization of hybrid contrast agents based on gadolinium doped magnetite

Magnetic Resonance Tomography, MRI, is one of the most used instruments for non-invasive clinical diagnostics. In contrast to radiological investigations, MRI has no danger of radiation exposure to produce images using radio... [ view full abstract ]

Magnetic Resonance Tomography, MRI, is one of the most used instruments for non-invasive clinical diagnostics. In contrast to radiological investigations, MRI has no danger of radiation exposure to produce images using radio frequency electromagnetic radiation with very low energy. The most researches in this area are focused on the development of contrast agents, that can provide a clearer distinction between healthy and diseased tissue. The majority of contrast agents are magnetic nanoparticles (MNP).
MNPs of iron oxide are used for the diagnostics of many diseases such as cardiovascular, neurological and cancer tumors. Liver and prostate cancer are the most prevalent of malignant tumors. Currently a priority researches of contrast agents for MRI are hybrid contrast agents, providing comprehensive diagnostic information about the dynamics of the disease progression. Gadolinium chelates and magnetite are the most appropriate T1 and T2 contrast agents, respectively, but these compounds can provide toxic effect on healthy cells. One of the ways to prevent toxicity is the creation of hybrid contrast agents based on gadolinium doped magnetite.
In this work gadolinium doped magnetite nanoparticles were prepared by two techniques: thermal decomposition of iron and gadolinium acetylacetonates in diphenyl ether and hydrolysis of Fe3+ и Gd3+ salts mixture in the presence of polyethyleneimine, followed by addition of hydrazine hydrate and microwave irradiation. These nanoparticles are designed to be used as a hybrid contrast agents for hepatocellular and prostate carcinomas visualization.
Obtained nanoparticles were investigated by methods of transmission electron microscopy, X-ray diffraction, Mössbauer spectroscopy, VSM magnetometry and thermogravimetric analysis. Also the toxicity of nanoparticles and their T2-relaxation time were measured in vitro. In vivo examinations on mouse model of liver cancer were carried out.

The authors knowledge financial support from Ministry of Education and Science of the Russian Federation (14.607.21.0132, RFMEFI60715X0132).