Investigation of cellular uptake and transport capacity of Cordyceps sinensis exopolysaccharide­selenium nanoparticles with different particle sizes in Caco-2 cell monolayer.

Cordyceps sinensis exopolysaccharide­selenium nanoparticles (EPS-SeNPs) were successfully constructed, characterized, and its Se release kinetics and mechanism were also evaluated in our previous studies. However, the intestinal cellular uptake and transport capacities of EPS-SeNPs remain unknown. On the basis of our previous researches, this work was designed to evaluate the uptake and transport capacities of EPS-SeNPs (EPS/Se = 20/1, 3/1, 1/1, and 3/4) in intestinal epithelial (Caco-2) cells. Confocal laser scanning microscopy results indicated that the internalization of coumarin-6 labeled EPS-SeNPs was in a time-dependent process and eventually located in the cytoplasm, not in the nucleus. Endocytosis inhibitors were employed to evaluate the cellular uptake pathway of EPS-SeNPs, relevant results revealed that clathrin-, caveolae-, and energy-mediated pathways were participated in the internalization of EPS-SeNPs by Caco-2 cells. In addition, the transportation of EPS-SeNPs across Caco-2 cell monolayers was in a concentration-dependent manner. Different particle sizes of EPS-SeNPs presented different uptake and transport capacities in Caco-2 cells. Noteworthy, EPS/Se = 3/4 with the highest selenium content possessed the most superior cellular uptake and transport abilities in Caco-2 cells. The present work may contribute to illustrate the internalization and transport mechanism of EPS-SeNPs, thus facilitating its application in food and medical industries.

The cellular uptake of Cordyceps sinensis exopolysaccharide­selenium nanoparticles and their induced apoptosis of HepG2 cells via mitochondria- and death receptor-mediated pathways.

This wok investigated the effects of Cordyceps sinensis exopolysaccharide­selenium nanoparticles (EPS-SeNPs), EPS-Se-1, EPS-Se-2, EPS-Se-3, and EPS-Se-4) with particle sizes (79-124 nm) and Se contents (20.11-40.80 µg/mg) on endocytosis and antitumor activity against human hepatocellular carcinoma (HepG2) cells and revealed the apoptosis-related mechanisms. EPS-SeNPs inhibited HepG2 cells proliferation in a dose and Se content-dependent manner by disrupting cell membrane and mitochondrial integrity, promoting reactive oxygen species production. EPS-SeNPs were endocytosed by HepG2 cells through a clathrin-mediated pathway and followed the quasi-first-order kinetics model, indicating physical adsorption played a dominant role in cellular uptake behavior of EPS-SeNPs. Notably, EPS-Se-3 with the lowest particle size (79 nm) showed the highest antitumor activity and the strongest ability to promote cell apoptosis. Western blotting results revealed that EPS-Se-3 increased expressions of Bax, Cytochrome c, cleaved caspase-9, cleaved caspase-3, Fas, p53, and cleaved caspase-8, while decreased the expressions of Bcl-2 and PARP, as contrast to that of control. Overall, EPS-SeNPs induced cell apoptosis through intrinsic mitochondria-mediated and extrinsic death receptor-mediated pathways.

Protective effects of Cordyceps sinensis exopolysaccharide­selenium nanoparticles on H2O2-induced oxidative stress in HepG2 cells.

This work investigated the protective effects of Cordyceps sinensis exopolysaccharide­selenium nanoparticles (EPS-SeNPs) at different Se/EPS ratios (1/20, 1/3, 1/1, and 4/3) against 0.4 mM H2O2-induced oxidative stress in human hepatoma (HepG2) cells. Results revealed that EPS-SeNPs (0.1-4.0 µg/mL) promoted the proliferation of HepG2 cells with a cell viability of over 90% during H2O2 stress. Different Se/EPS ratios of EPS-SeNPs provided protective effects against H2O2-induced oxidative stress in HepG2 cells by increasing cell viability, restoring cell and nucleus morphology, as well as reducing lactate dehydrogenase (LDH) levels. Particularly, EPS-SeNPs (Se/EPS = 1/1) with the smallest particle size showed the highest cell viability and the greatest inhibitory effect on LDH level. Besides, EPS-SeNPs also inhibited nitric oxide and reactive oxygen species (ROS) production, and increased mitochondrial membrane potential, superoxide dismutase (SOD), and catalase levels while reducing glutathione (GSH) content. Specially, EPS-SeNPs at Se/EPS ratio of 1/3 with smaller size showed the lowest ROS level and the highest antioxidant activities (SOD and GSH), implying that the ROS generation was inhibited by increasing enzymatic and non-enzymatic antioxidants. The enhanced protective effect of EPS-SeNPs (Se/EPS = 1/1 and 1/3) might be attributed to its smaller particle size.

Photo-Assisted Rechargeable Battery Desalination.

Herein, we propose a novel design of photo-assisted battery desalination, which provides the tri-function within a single device including the photo-assisted charge (electrical energy saving), energy storage, and desalination (salt removal). The photoelectrode (N719/TiO2) is directly integrated into the zinc-iodide (Zn-I) battery with the desalination stream in the middle portion of the device. This architecture can provide a reduced energy consumption up to 50%, an energy output of 42 W h mol-1NaCl, and a desalination rate of 13 µg/cm2 min-1. This work is significant for the inter-discipline study of the redox flow energy storage and energy-saving desalination.

Structure, size and aggregated morphology of a ß-D-glucan from Lignosus rhinocerotis as affected by ultrasound.

The effect of ultrasonic treatment on the structure, size and aggregated morphology of Lignosus rhinocerotis polysaccharide (LRP) was investigated. Ultrasonic treatment for 10 min has demonstrated to improve the aqueous solubility of LRP, leading to a uniform and narrow LRP particle size distribution. Meanwhile, short-time ultrasound was found to obviously decrease the molecular size parameters (Mw, Mn, z1/2, [η] and Rh) of LRP, and transform the hyperbranched LRP molecules into flexible and extended chains, which would reaggregate to form spherical aggregates under long-time ultrasonication. Additionally, Congo red experiment combined with CD analysis indicated the existence of triple helix structure in LRP, which was still retained after ultrasonic treatment. Furthermore, under short-time ultrasonication, the spherical aggregates with some branched chains in the native LRP solution could disaggregate and form triple helixes that could be further arranged to a dense network structure, but the untangled LRP chains would reaggregate after long-time ultrasonication. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: Congo red (PubChem CID: 11313); Sodium hydroxide (PubChem CID: 14798); Potassium bromide (PubChem CID: 253877).

Selenium release kinetics and mechanism from Cordyceps sinensis exopolysaccharide-selenium composite nanoparticles in simulated gastrointestinal conditions.

This work investigated selenium (Se) release kinetics and mechanism from exopolysaccharide-selenium nanoparticles (EPS-SeNPs, Se/EPS = 1/20, 1/1 and 4/3) in simulated gastric (SGF) and intestinal fluids (SIF) using kinetics models of Zero order, First order, Higuchi, Hixson-Crowell and Korsmeyer-Peppas. EPS-SeNPs showed an increase in size from 80-125 nm to 250-320 nm and more ambiguous boundary after gastrointestinal digestion. Se/EPS ratio and pH had significant influence on Se release. Se release kinetics from EPS-SeNPs (Se/EPS = 1/1 and 4/3 in SGF) followed a classical Fickian diffusion, in contrast to an erosion governed by macromolecular chains relaxation for Se/EPS = 1/20 in SIF. Se release from EPS-SeNPs (Se/EPS = 1/1 and 4/3 in SIF) was well-fitted to Korsmeyer-Peppas model and followed a non-Fickian mechanism controlled by both diffusion and erosion. Additionally, EPS-SeNPs (Se/EPS = 1/20) showed a low Se release after SGF digestion, but a high release after SIF digestion, suggesting its application in controlled release of Se-enriched supplements for Se-deficiency treatment.

How Air Quality Affect Health Industry Stock Returns: New Evidence From the Quantile-on-Quantile Regression.

This paper discusses the asymmetric effect of air quality (AQ) on stock returns (SR) in China's health industry through the quantile-on-quantile (QQ) regression method. Compared to prior literature, our study provides the following contributions. Government intervention, especially industrial policy, is considered a fresh and essential component of analyzing frameworks in addition to investors' physiology and psychology. Next, because of the heterogeneous responses from different industries to AQ, industrial heterogeneity is thus considered in this paper. In addition, the QQ method examines the effect of specific quantiles between variables and does not consider structural break and temporal lag effects. We obtain the following empirical results. First, the coefficients between AQ and SR in the health service and health technology industries change from positive to negative as AQ deteriorates. Second, AQ always positively influences the health business industry, but the values of the coefficients are larger in good air. In addition, different from other industries, the coefficients in the health equipment industry are negative, but the values of the coefficients change with AQ. The conclusions provide important references for investors and other market participants to avoid biased decisions due to poor AQ and pay attention to government industrial policies.

Structure characteristics, solution properties and morphology of oxidized yeast ß-glucans derived from controlled TEMPO-mediated oxidation.

This work was to investigate the effect of the degree of oxidation (DO) on the structure, solution properties and morphology of yeast ß-glucan. Five different degrees of oxidized yeast ß-glucan (OYG1-5) samples were controllably prepared by TEMPO-mediated oxidation on C-6 position. Namely, the -CH2OH units were oxidized into -COO-/-COOH, and the DO was quantified to be 10.0∼71.2% by potentiometric titration. With an increase of the DO, the OYG samples had a remarkable increase in solubility as indicated by the decreasing turbidity, particle size and zeta-potential, and showed an overall decrease from 2.63 × 106 to 1.43 × 105 g/mol in molecular weight and from 3.95 to 1.66 in polydispersity. OYG1-4 with DO from 10.0% to 47.3% had aggregate morphology with different sizes, while OYG5 with DO of 71.2% showed uniformly dispersed chains and a loose network formed by chain entanglement. These findings demonstrated that the solution properties and morphology of yeast ß-glucan can be altered by adjusting the DO.

Effects and mechanisms of ultrasound- and alkali-assisted enzymolysis on production of water-soluble yeast ß-glucan.

This study investigated the effects and related mechanisms of ultrasound- and alkali-assisted enzymolysis on production of water-soluble yeast ß-glucan (WSYG). Results indicated that ultrasound and alkali pretreatments reduced the particle size of yeast ß-glucan (YG) from 8.80 µm to 1.77 and 7.19 µm, respectively. Ultrasound-induced cavitation disrupted YG aggregates to a coarse appearance and exposed internal structure. Alkali penetrated into YG particles and broke the YG aggregates into a flake-like morphology by cleaving the linkages within YG chains. Both pretreatments facilitated enzymolysis by enlarging the YG surface area and increased the WSYG yield to 32.3% and 36.2%, respectively. Meanwhile, the purity of WSYG reached 98.8% after zymoprotein removal by DEAE-Sepharose fast flow column. This work not only provides a green method for producing high-purity and high-yield WSYG, but also reveals the mechanisms of ultrasound and alkali pretreatments for improving enzymolysis efficiency by loosening the YG structure and increasing the surface area.

Effect of ultrasound on size, morphology, stability and antioxidant activity of selenium nanoparticles dispersed by a hyperbranched polysaccharide from Lignosus rhinocerotis.

The differences between ultrasonic and non-ultrasonic approaches in synthesizing Lignosus rhinocerotis polysaccharide-selenium nanoparticles (LRP-SeNPs) were compared in terms of size, morphology, stability and antioxidant activity by UV-VIS, FT-IR, X-ray diffraction (XRD), dynamic light scattering (DLS), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) with high resolution TEM. Results indicated that the SeNPs were associated with the LRP macromolecules in a physical adsorption pattern without breaking chemical bonds, and the ultrasonic treatment reduced the size of SeNPs, narrowed the size distribution as well as improved the stability. Due to the LRP compact coil structure loosed under ultrasonic cavitation, the SeNPs could be easily diffused into the LRP internal branches instead of gathering on the LRP surface and were well dispersed and eventually stabilized throughout the extended branches. After ultrasound treatment, the SeNPs had a minimum average diameter of ∼50 nm and the LRP-SeNPs could remain homogeneous and translucent for 16 days within 200 nm size. Furthermore, the ultrasound-treated LRP-SeNPs exhibited higher DPPH and ABTS radical-scavenging abilities than those untreated with ultrasound. This difference may be attributed to the reason that ultrasound can reduce the SeNPs size and increase the specific surface area, which provides sufficient active sites to react with the free radicals and suppress the oxidizing reactions. The integrated results demonstrated that ultrasound played a crucial role in the dispersion, size control, stabilization and antioxidant activity of SeNPs.

Construction of a Cordyceps sinensis exopolysaccharide-conjugated selenium nanoparticles and enhancement of their antioxidant activities.

A Cordyceps sinensis exopolysaccharide (EPS)-conjugated selenium nanoparticles (SeNPs) were successfully constructed through the reduction of SeO32-. The EPS-SeNPs were characterized in terms of formation, morphology, size, Se distribution and phase by UV-vis, FT-IR, transmission electron microscopy (TEM), dynamic light scattering (DLS), energy dispersive X-ray (EDX) and wide angle X-ray diffraction (WAXD) measurements. Results revealed that the SeNPs conjugated to EPS were amorphous and could be well dispersed at a size range of 80-125nm. The interactions between the OH groups of EPS and SeNPs substituted for intermolecular interaction in native EPS to form new CO⋯Se bonds, resulting in good dispersion of SeNPs in the EPS matrix. Besides, the EPS-SeNPs at different Se/P ratios exhibited significant scavenging ability on superoxide anion radical (O2-) and ABTS radical cation (ABTS+) when compared to pure EPS, indicating that the conjugated SeNPs reinforced antioxidant effect of EPS. This work not only provides a simple and efficient way to construct well-dispersed SeNPs in aqueous system, and demonstrates the vital role of the EPS as a biopolymer template for dispersion, stabilization and size control of SeNPs, but also finds the EPS-SeNPs can potentially serve as a good antioxidant towards O2- and ABTS+.