Magnetic nanoparticles used in MRI appear to migrate and age

This conclusion was made by scientists from the Engineering Physics Institute of Biomedicine of the National Research Nuclear University MEPhI and specialists from the Institute of General Physics of the Russian Academy of Sciences. They studied the activity of magnetic nanoparticles in mice, which are used in magnetic resonance imaging.

It turned out that at first the nanoparticles accumulate in the liver and spleen, but over time, their contrast begins to decrease, especially with repeated MRI. In addition, these particles can aggregate with each other, change their magnetic properties, and move both between cells and between organs.

It was also found that within two hours the nanoparticles were completely removed from the bloodstream, but their initial biodistribution changed over time. For example, their number in the spleen increased over time, which may indicate migration from other organs. The nanoparticles remained in the liver and spleen for about a month, and disappeared from other organs after a week.

According to the head of the study, MEPhI Associate Professor Petr Nikitin, a special magnetic detection method was developed to accurately measure the amount of magnetic nanoparticles in the body, which makes it possible to reliably distinguish magnetic particle signals from surrounding tissues, including natural forms of iron.

“Measurements can be carried out directly in a living animal, saving its life and obtaining information about the long-term biodegradation of particles in each individual,” said Pyotr Nikitin. “In addition, the data we obtained confidently showed the safety of magnetic particles.

Mona Platonov.