Selenium-Nanoparticles-Loaded Chitosan/Chitooligosaccharide Microparticles and Their Antioxidant Potential: A Chemical and In Vivo Investigation

Abstract

Selenium nanoparticles (SeNPs) have attracted attention due to their favorable properties, unique bioactivities, and potential for use in nutritional supplements and nanomedicine applications. However, the application of SeNPs in the clinic has been greatly hindered by their poor stability, and their potential to protect against alcohol-induced oxidative stress has not been fully investigated. Herein, SeNPs were synthesized in the presence of chitosan (CS) or chitooligosaccharide (COS), and a mixture of SeNPs, CS, and COS was spray-dried to prepare selenium-nanoparticles-loaded chitosan/chitooligosaccharide microparticles (SeNPs-CS/COS-Ms). Their physicochemical properties, including morphology, elemental state, size distribution, surface potential, and characteristic structure, were investigated. The release of SeNPs from the vehicle and the free radical scavenging ability of SeNPs-CS/COS-Ms were also studied. Furthermore, the safety of SeNPs-CS/COS-Ms and their antioxidant activity against alcohol were evaluated in mice. The results indicate that SeNPs-CS/COS-Ms, with a novel structure characterized by their smooth or wrinkled surface, hollow core, and COS body filled with SeNPs-CS nanobeads, were able to release SeNPs and scavenge DPPH and superoxide anion radicals. SeNPs-CS/COS-Ms were found to be much safer than selenite, and they might protect mice from ethanol-induced oxidative stress by reducing lipid and protein oxidation and by boosting glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT). In conclusion, SeNPs-CS/COS-Ms offer a new way to develop stable SeNPs with higher efficacy and better biosafety, and the antioxidant potential of SeNPs-CS/COS-Ms against ethanol deserves further development.

Keywords: alcohol; antioxidant; chitooligosaccharide; chitosan; nano; selenium.

Figure 1

Typical morphology and formation of selenium nanoparticles (SeNPs). TEM images of (A) bare SeNPs, (B) chitooligosaccharide (COS)-SeNPs, and (C) chitosan (CS)-SeNPs. (D) EDS spectra of CS-SeNPs determined from the area shown in Figure 1C. (E) The size distribution of CS-SeNPs measured from the TEM results. (F) Zeta-potentials of bare SeNPs, COS-SeNPs, and CS-SeNPs, measured at a pH of 5.0 ± 0.3.

Figure 2

The typical morphology and chemical properties of selenium-nanoparticles-loaded chitosan/chitooligosaccharide microparticles (SeNPs-CS/COS-Ms). (A) An SEM image of SeNPs-CS/COS-Ms. (B) The size distribution of SeNPs-CS/COS-Ms in ethanol (upper) and in water (lower). (C) An SEM image of SeNPs-CS/COS-Ms after ultrasonic disruption in absolute ethanol. (D–E) SEM images of SeNPs-CS/COS-Ms at different magnifications, exactly (D) 16,000× and (E) 50,000×, after ultrasonic disruption in 50% ethanol. (F) FTIR spectra of bare SeNPs, CS/COS, and SeNPs-CS/COS-Ms. (G–I) XPS results, including (G) wide-range XPS patterns, (H) Se 3d scan XPS patterns composed of Se 3d3 and Se 3d5 signals, and (I) Se 3p scan XPS patterns. In Panel (E), smaller arrows indicate CS-SeNP nanobeads, while the bigger one represents the linear CS structure.

Figure 3

The release of SeNPs from SeNPs-CS/COS-Ms in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). (A) A typical TEM image of the released SeNPs in SGF or SIF. (B,C) The relative release rates of SeNPs from SeNPs-CS/COS-Ms with different material ratios of CS:COS (75:25, 25:75, and 10:90) in (B) SGF and (C) SIF.

Figure 4

Free radical scavenging abilities against (A) DPPH (•DPPH) and (B) superoxide anion (•O₂⁻) radicals. SeNPs-CS/COS-Ms containing 15 mg Se/kg (CS:COS = 10:90) and CS/COS-Ms (CS:COS = 10:90) were evaluated in this section.

Figure 5

The serum Se retention within KM mice. The dose of each group is presented in Table 1. * p < 0.05, ** p < 0.01 versus the Model group; ^$ p < 0.05 versus the CS/COS microsphere (CS/COS-M) group.