Mathematical simulation of the biokinetics of selenium nanoparticles and salt forms in living organisms

A mathematical simulation of the absorption, distribution, metabolism, and excretion from the body of radioisotope-labeled nanoparticles (NPs) of elemental selenium (Se) in comparison with the traditional form of the trace elements (sodium selenite) has been performed, with them being administered in the gastrointestinal tract of rats that are normally supplied with Se or experience its nutritional deficiency. A compartmental mathematical model that describes the biokinetics of the mentioned Se forms at different levels of its supply is constructed. The quantitative parameters of the model are set using the experimental data from a biokinetic study on rats who, via their gastrointestinal tract, received [75Se]-labeled sodium selenite or Se NPs which were obtained by laser ablation and had an average diameter of 97 ± 5 nm. The proposed model, despite the number of necessary simplifications, satisfactorily explains the difference between the experimental data for both Se-supplied and Se-deficient groups of animals. Thus, in the case of Se deficiency, its assimilation by organs occurs more actively than when it is supplied normally. Se in the form of NPs is preferable to its salt form due to the slower formation of HSe- anion and excretable Se forms, which are potentially highly toxic. This conclusion is consistent with the hypothesis that Se NPs may be the basis for the development of a new generation of dietary sources of selenium.