Biokinetic study of selenium nanoparticles and salt forms in living organisms

An experimental study of absorption, distribution, metabolism, and excretion from the body of radioisotope-labeled nanoparticles (NPs) of elemental Se in comparison with the traditional form of this trace element (sodium selenite) has been performed, being administered in the gastrointestinal tract of rats that were normally supplied with Se or experiencing its nutritional deficiency. Nuclear activation analysis is used for the detection of Se in the biological tissue, which is based on the measurement of a gamma-emitting label [75Se34] that is introduced in the Se NPs or its salt by thermal neutron irradiation in a nuclear reactor. It is shown that Se NPs administered into the gastrointestinal tract have bioavailability comparable to the salt form of this element. According to some experimental data, the metabolic assimilation of both forms of Se is greater in animals that suffer from a deficiency in this element when compared to those that are normally supplied with it. There are some differences in the kinetics of accumulation of Se NPs and its salts in the blood and liver, which can be explained by the presence of limiting steps in the absorption and biotransformation of Se-containing NPs. The retention of Se that is administered in the form of NPs or salts to Se-deficient animals differs significantly. These results demonstrate the capacity of the Se NPs to be a source of Se in a new generation of biologically active food supplements.