Nano-selenium and its nanomedicine applications: a critical review

Abstract

Traditional supplements of selenium generally have a low degree of absorption and increased toxicity. Therefore, it is imperative to develop innovative systems as transporters of selenium compounds, which would raise the bioavailability of this element and allow its controlled release in the organism. Nanoscale selenium has attracted a great interest as a food additive especially in individuals with selenium deficiency, but also as a therapeutic agent without significant side effects in medicine. This review is focused on the incorporation of nanotechnological applications, in particular exploring the possibilities of a more effective way of administration, especially in selenium-deficient organisms. In addition, this review summarizes the survey of knowledge on selenium nanoparticles, their biological effects in the organism, advantages, absorption mechanisms, and nanotechnological applications for peroral administration.

Keywords: anticancer effect; antimicrobial activity; biomedicine; drug delivery; nanoparticles; oxidative stress; protective effect.

Figure 1

Diagram showing the main advantages of nanoparticles (NPs). Note: Data from various studies.,,,–

Figure 2

Scheme of preparation of selenium nanoparticles (SeNPs). Notes: For the synthesis of SeNPs, the selenious acid solution (aqueous solution of SeO₂) (1) is mixed with an aqueous solution of a polysaccharide, for example, chitosan (2), and ascorbic acid solution (3), which gradually transforms the initially colorless solution into a red color solution (4). In the next step, elemental SeNPs are coated with chitosan, and the result is encapsulated nano-selenium form (5, in detail 6).,

Figure 3

Diagram showing the main effects of selenium nanoparticles (SeNPs). Note: Data from various sources.,,–,,,,,,,,,,–

Figure 4

Diagram of nanoparticle transport across the intestinal mucosa of the small intestine. Particles pass either paracellularly, that is, between adjacent cells, or by a transcellular pathway that has been more explored. The transcellular transition takes place via normal enterocytes or M cells. A, paracellular transport; B, transcellular transport: transcytosis through M cell; C₁, transcytosis through enterocyte, first mechanism; C₂, transcytosis through enterocyte, second mechanism; 1, apical membrane of enterocyte; 2, the basolateral membrane of the enterocyte. M cells form a row of vesicles before transfer from subepithelial dome dendritic cells (SDDCs) to T- or B-lymphocytes (B). Uptake of nanoparticles by microvilli of enterocytes is often followed by endosome formation, microvesicular bodies (MVBs) genesis, and their fusion with lysosomes, and then the particles are transported to lamina propria (C₁). Another mechanism of enterocyte utilization for transepithelial transport involves uptake into endosomes, MVB formation, fusion with Golgi apparatus, and exosomal transfer to lamina propria (C₂). This is followed by transport into the bloodstream and the lymphatic system.,