Preparation and characterization of selenium nanoparticles decorated by Spirulina platensis polysaccharide

Ultrasound-driven facile fabrication of Pd doped SnO2 hierarchical superstructures: Structural, growth mechanism, dermatoglyphics, and anti-cancer activity

This research introduces a novel method that leverages Spirulina extract (S.E) as a bio-surfactant in the ultrasound-assisted synthesis (UAS) of Pd3+ (0.25-10 mol%) doped tin oxide (SnO2) self-assembled superstructures. Nanotechnology has witnessed significant advancements in recent years, driven by the exploration of novel synthesis methods and the development of advanced nanomaterials tailored for specific applications. Metal oxide nanoparticles, particularly SnO2, have garnered considerable attention due to their versatile properties and potential applications in various fields, including gas sensing, catalysis, and biomedical engineering. The study explores how varying influential parameters like S.E concentration, sonication time, pH, and sonication power can influence the resulting superstructures' morphology, size, and shape. A theoretical model for forming different hierarchical superstructures (HS) is proposed. X-ray diffraction (XRD) analysis confirms the crystalline tetragonal rutile phase of the SnO2:Pd HS. Raman spectroscopy reveals a red shift in the A1g mode, indicating phonon confinement due to various defects in the SnO2 structure. Further characterization using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) provides insights into particle size, surface morphology, elemental composition, and binding energy. The study also demonstrates the application of optimized SnO2:3Pd HS in developing latent fingerprints (LFPs) on different surfaces using a simple powder dusting (PD) method, with the fingerprints (FPs) visualized under normal light. A mathematical model developed in Python-based software is used to analyze various features of the developed FPs, including pore properties such as number, position, inter-spacing, area, and shape. Additionally, an in vitro MTT assay shows concentration-dependent anticancer activity of SnO2:3Pd nanoparticles (NPs) on MCF7 cell lines, highlighting their potential as a promising cancer treatment option. Overall, the study suggests that the optimized HS can serve as multifunctional platforms for biomedical and dermatoglyphics applications, demonstrating the versatility and potential of the synthesized materials.

In vitro assessment of the effect of magnetic fields on efficacy of biosynthesized selenium nanoparticles by Alborzia kermanshahica

Cyanobacteria represent a rich resource of a wide array of unique bioactive compounds that are proving to be potent sources of anticancer drugs. Selenium nanoparticles (SeNPs) have shown an increasing potential as major therapeutic platforms and led to the production of higher levels of ROS that can present desirable anticancer properties. Chitosan-SeNPs have also presented antitumor properties against hepatic cancer cell lines, especially the Cht-NP (Chitosan-NPs), promoting ROS generation and mitochondria dysfunction. It is proposed that magnetic fields can add new dimensions to nanoparticle applications. Hence, in this study, the biosynthesis of SeNPs using Alborzia kermanshahica and chitosan (CS) as stabilizers has been developed. The SeNPs synthesis was performed at different cyanobacterial cultivation conditions, including control (without magnetic field) and magnetic fields of 30 mT and 60 mT. The SeNPs were characterized by uv-visible spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), Dynamic light scattering (DLS), zeta potential, and TEM. In addition, the antibacterial activity, inhibition of bacterial growth, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC), as well as the antifungal activity and cytotoxicity of SeNPs, were performed. The results of uv-visible spectrometry, DLS, and zeta potential showed that 60 mT had the highest value regarding the adsorption, size, and stabilization in compared to the control. FTIR spectroscopy results showed consistent spectra, but the increased intensity of peaks indicates an increase in bond number after exposure to 30 mT and 60 mT. The results of the antibacterial activity and the inhibition zone diameter of synthesized nanoparticles showed that Staphylococcus aureus was more sensitive to nanoparticles produced under 60 mT. Se-NPs produced by Alborzia kermanshahica cultured under a 60 mT magnetic field exhibit potent antimicrobial and anticancer properties, making them a promising natural agent for use in the pharmaceutical and biomedical industries.

Preparation, Characterization, and Bioactivities of Polysaccharide-Nano-Selenium and Selenized Polysaccharides from Acanthopanax senticosus

Acanthopanax senticosus polysaccharide-nano-selenium (ASPS-SENPS) and A. selenopanax selenized polysaccharides (Se-ASPS) were synthesized, and their characterization and biological properties were compared. The acid extraction method was used to extract the polysaccharides of A. selenopanax, followed by decolorization using the hydrogen peroxide method and deproteinization based on the Sevage method, and the purification of A. senticosus polysaccharides (ASPS) was carried out using the cellulose DEAE-52 ion column layer analysis method. An A. senticosus polysaccharide-nano-selenium complex was synthesized by a chemical reduction method using ASPS as dispersants. The selenization of polysaccharides from A. selenopanax was carried out using the HNO3-Na2SeO3 method. The chemical compositions, scanning electron microscopy images, infrared spectra, and antioxidant properties of ASPS-SENPS and Se-ASPS were studied, and they were also subjected to thermogravimetric analysis. The results indicated that the optimal conditions for the synthesis of ASPS-SENPS include the following: when ASPS accounts for 10%, the ratio of ascorbic acid and sodium selenium should be 4:1, the response time should be 4 h, and the reaction temperature should be 50 °C. The most favorable conditions for the synthesis of Se-ASPS were as follows: m (Na2SeO3):m (ASPS) = 4:5, response temperature = 50 °C, and response time = 11.0 h. In the in vitro antioxidant assay, when the mass concentration of Se-ASPS and ASPS-SENPS was 5 mg/mL, the removal rates for DPPH free radicals were 88.44 ± 2.83% and 98.89 ± 3.57%, respectively, and the removal rates for ABTS free radicals were 90.11 ± 3.43% and 98.99 ± 1.73%, respectively, stronger than those for ASPS. The current study compares the physiological and bioactivity effects of ASPS-SENPS and Se-ASPS, providing a basis for future studies on polysaccharides.

Anti-breast cancer activity of biosynthesized selenium nanoparticles using Bacillus coagulans supernatant

BACKGROUND

In the present study, Selenium Nanoparticles (SeNPs) were prepared using Bacillus coagulans, which is a type of Lactic Acid Bacteria (LAB), and then they were applied to treat breast cancer cells.

METHODS

The chemicophysical properties of the bioengineered SeNPs were investigated by Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), zeta potential, dynamic light scattering, Fourier Transform Infrared Spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD). The cytotoxic potential of SeNPs was evaluated by MTT assay against MCF-7 breast cancer cell line. The expression levels of apoptotic genes including BAX, BCL2, VEGF, ERBB2, CASP3, CASP9, CCNE1, CCND1, MMP2 and MMP9 were determined by real-time PCR. The rate of apoptosis and necrosis of the cancer cells as well as the results of the cell cycle were evaluated by flow cytometry method.

RESULTS

The synthesized SeNPs had an average particle size of about 24-40 nm and a zeta potential of -16.1 mV, indicating the high stability of SeNPs. EDX results showed presence of SeNPs because amount of selenium in SeNPs was 86.6 % by weight. The cytotoxicity results showed a concentration-dependent effect against MCF-7 cells. The half-maximal inhibitory concentration (IC50) values of B. coagulans supernatant and SeNPs against breast cancer cells were 389.7 µg/mL and 17.56 µg/mL, respectively. In addition, SeNPs synthesized by the green process exhibited enhanced apoptotic potential in MCF-7 cancer cells compared with bacterial supernatants. Cancer cells treated with IC50 concentration of SeNPs induced 32 % apoptosis compared to untreated cells (3 % apoptosis). The gene expression levels of BAX, CASP3, and CASP9 were upregulated, while the expression levels of BCL2, CCNE1, CCND1, MMP2, MMP9, VEGF, and ERBB2 were downregulated after SeNPs treatment of cells. The potential of SeNPs to induce cell apoptosis was demonstrated by the increase in the expression level of BAX gene and the decrease in the expression level of BCL2 after treatment of cancer cells with SeNPs.

CONCLUSION

The obtained results indicated that SeNPs had strong potential to induce significant cell apoptosis and are cytotoxic against the MCF-7 cancer cell line.

Enhanced Induction of Apoptosis and Cell Cycle Arrest in MCF-7 Breast Cancer and HT-29 Colon Cancer Cell Lines via Low-Dose Biosynthesis of Selenium Nanoparticles Utilizing Lactobacillus casei

As a leading global cause of mortality, cancer continues to pose a significant challenge. The shortcomings of prevalent cancer treatments, such as surgery, radiation therapy, and chemotherapy, necessitate the exploration of alternative therapeutic strategies. Selenium nanoparticles (SeNPs) have emerged as a promising solution, with their synthesis being widely researched due to their potential applications. Among the diverse synthesis methods for SeNPs, the green chemistry approach holds a distinctive position within nanotechnology. This research delves into the anti-proliferative and anticancer properties of green-synthesized SeNPs via the cell-free supernatant (CFS) of Lactobacillus casei (LC-SeNPs), with a specific focus on MCF-7 and HT-29 cancer cell lines. SeNPs were synthesized employing the supernatant of L. casei. The characterization of these green-synthesized SeNPs was performed using TEM, FE-SEM, XRD, FT-IR, UV-vis, energy-dispersive X-ray spectroscopy, and DLS. The biological impact of LC-SNPs on MCF-7 and HT-29 cancer cells was examined via MTT, flow cytometry, scratch tests, and qRT-PCR. Both FE-SEM and TEM images substantiated the spherical shape of the synthesized nanoparticles. The biosynthesized LC-SNPs reduced the survival of MCF-7 (by 20%) and HT-29 (by 30%) cells at a concentration of 100 μg/mL. Flow cytometry revealed that LC-SNPs were capable of inducing 28% and 23% apoptosis in MCF-7 and HT-29 cells, respectively. In addition, it was found that LC-SNPs treated MCF-7 and HT-29 cells were arrested in the sub-G1 phase. Gene expression analysis indicated that the expression levels of the CASP3, CASP9, and BAX genes were elevated after treating MCF-7 and HT-29 cells with LC-SNPs. Further, SeNPs were observed to inhibit migration and invasion of MCF-7 and HT-29 cancer cells. The SeNPs, produced via L. casei, demonstrated strong anticancer effects on MCF-7 and HT-29 cells, suggesting their potential as biological agents in cancer treatment following additional in vivo experiments.

Advances in the Synthesis and Bioactivity of Polysaccharide Selenium Nanoparticles: A Review

Selenium, an essential trace element of the human body, is pivotal in human health and disease prevention. Nevertheless, the narrow therapeutic index of selenium, where the toxic and therapeutic doses are close, limits its clinical utility. Significantly, nanoscale selenium synthesized by different methods using polysaccharides as stabilizers has low toxicity properties and exhibits excellent bioactivity. Its biological activities, such as anti-tumor, anti-inflammatory, antioxidant, antibacterial, and immune function enhancement, are improved compared with traditional organic and inorganic selenium compounds, conferring greater potential for application in biomedicine. Therefore, this review evaluates the advancements in various synthesis methodologies for polysaccharide selenium nanoparticles (Se NPs) and their biological activities. It aims to provide a comprehensive theoretical basis and research directions for the future development of highly efficient, minimally toxic, and biocompatible polysaccharide-Se NPs and the application of polysaccharide-Se NPs in biomedicine.

The potential, challenges, and prospects of the genus Spirulina polysaccharides as future multipurpose biomacromolecules

Spirulina has been widely used worldwide as a food and medicinal ingredient for centuries. Polysaccharides are major bioactive constituents of Spirulina and are of interest because of their functional properties and unlimited application potential. However, the clinical translation and market industrialization of the polysaccharides from genus Spirulina (PGS) are retarded due to the lack of a further understanding of their isolation, bioactivities, structure-activity relationships (SARs), toxicity, and, most importantly, versatile applications. Herein, we provide an overview of the extraction, purification, and structural features of PGS; meanwhile, the advances in bioactivities, SARs, mechanisms of effects, and toxicity are discussed and summarized. Furthermore, the applications, potential developments, and future research directions are scrutinized and highlighted. This review may help fill the knowledge gap between theoretical insights and practical applications and guide future research and industrial application of PGS.

Nano-elemental selenium particle developed via supramolecular self-assembly of chondroitin sulfate A and Na2SeO3 to repair cartilage lesions

Cartilage repair is a significant clinical issue due to its restricted ability to regenerate and self-heal after cartilage lesions or degenerative disease. Herein, a nano-elemental selenium particle (chondroitin sulfate A‑selenium nanoparticle, CSA-SeNP) is developed by the supramolecular self-assembly of Na₂SeO₃ and negatively charged chondroitin sulfate A (CSA) via electrostatic interactions or hydrogen bonds followed by in-situ reducing of l-ascorbic acid for cartilage lesions repair. The constructed micelle exhibits a hydrodynamic particle size of 171.50 ± 2.40 nm and an exceptionally high selenium loading capacity (9.05 ± 0.03 %) and can promote chondrocyte proliferation, increase cartilage thickness, and improve the ultrastructure of chondrocytes and organelles. It mainly enhances the sulfation modification of chondroitin sulfate by up-regulating the expression of chondroitin sulfate 4-O sulfotransferase-1, -2, -3, which in turn promotes the expression of aggrecan to repair articular and epiphyseal-plate cartilage lesions. The micelles combine the bio-activity of CSA with selenium nanoparticles (SeNPs), which are less toxic than Na₂SeO₃, and low doses of CSA-SeNP are even superior to inorganic selenium in repairing cartilage lesions in rats. Thus, the developed CSA-SeNP is anticipated to be a promising selenium supplementation preparation in clinical application to address the difficulty of healing cartilage lesions with outstanding repair effects.

Synthesis, characterization, and cytotoxicity analysis of selenium nanoparticles stabilized by Morchella sextelata polysaccharide

Natural bioactive molecules have been widely used as stabilizers in the functional improvement of selenium nanoparticles (SeNPs) in recent years. In this study, Morchella sextelata polysaccharide (MSP) was introduced as a novel stabilizer for the synthesis of SeNPs based on the redox system of sodium selenite and ascorbic acid. The size, morphology, stability, and anti-cancer cell activities were respectively analyzed by various methods. The results showed that the synthesized SeNPs with MSP were 72.07 ± 0.53 nm in size, red in color, spherical in shape, and amorphous in nature. MSP-SeNPs showed high scavenging activity against DPPH and ABTS radicals. And, these MSP-SeNPs exhibited a significant anti-proliferation effect on human liver (HepG2) and cervical cancer (Hela) cells in vitro, while no significant cytotoxicity against normal human kidney cells (HK-2) was observed. Moreover, the mitochondria-dependent apoptosis pathway triggered by MSP-SeNPs in HepG2 cell was identified. The expression levels of p53, Bax, cytochrome c, caspase-3 and caspase-9 were all up-regulated in HepG2 cells after MSP-SeNPs treatment, while Bcl-2 expression was down-regulated. These results suggest that MSP-SeNPs have strong potential as the food supplement for application in cancer chemoprevention.

Recent research progress on the synthesis and biological effects of selenium nanoparticles

Selenium is an essential trace element for the human body, with the chemical and physical characteristics of both metals and nonmetals. Selenium has bioactivities related to the immune system, antioxidation, anti-virus, and anti-cancer. At the same time, it also plays a role in reducing and alleviating the toxicity of heavy metals. Compared with inorganic selenium, organic selenium is less toxic and has greater bioavailability. Selenium nanoparticles (SeNPs) have the advantages of high absorption rate, high biological activity, and low toxicity, and can be directly absorbed by the human body and converted to organic selenium. Selenium nanoparticles have gradually replaced the traditional selenium supplement and has broad prospects in the food and medical industries. In this paper, the chemical, physical, and biological methods for the synthesis of selenium nanoparticles are reviewed, and the microbial synthesis methods of selenium nanoparticles, the effects of selenium nanoparticles on crop growth, and the antibacterial, antioxidant, anticancer, and anti-tumor effects of selenium nanoparticles are also systematically summarized. In addition, we evaluate the application of selenium nanoparticles in selenium nutrition enhancement, providing support for the application of selenium nanoparticles in animals, plants, and humans.

Preparation, characterization, and antioxidant and antiapoptotic activities of biosynthesized nano‑selenium by yak-derived Bacillus cereus and chitosan-encapsulated chemically synthesized nano‑selenium

Nano‑selenium (SeNPs) is a red elemental selenium with extremely small particles, which can be absorbed by the body and has biological activity. Currently, the most commonly used synthetic methods for SeNPs are biosynthesis and chemical synthesis. In this study, YC-3-SeNPs were biosynthesized by a strain of yak-gut Bacillus cereus YC-3, and meanwhile, CST-SeNPs were chemically synthesized and encapsulated with chitosan. A series of characterizations proved that YC-3-SeNPs and CST-SeNPs are spherical particles with excellent stability, and both have an excellent ability to scavenge free radicals in vitro. The particles of YC-3-SeNPs were encapsulated with polysaccharides, fiber, and protein, and it was less toxic than that of CST-SeNPs. Additionally, YC-3-SeNPs and CST-SeNPs may inhibit H₂O₂-induced oxidative stress in cardiomyocytes by activating the Keap1/Nrf2/HO-1 signaling pathway thereby scavenging ROS. Meanwhile, they may exert anti-apoptotic activity in cardiomyocytes by stabilizing mitochondrial membrane potential (∆Ψm) and balancing Bax/Bcl-2 protein, thereby reducing the protein expression of Cyt-c and Cleaved-caspase 3. Given the above, YC-3-SeNPs and CST-SeNPs with excellent antioxidant and anti-apoptotic activities may have broad application potential in the field of cardiovascular diseases.

Chitosan-sialic acid nanoparticles of selenium: Statistical optimization of production, characterization, and assessment of cytotoxic effects against two human glioblastoma cell lines

According to the favorable antitumor properties of selenium, this study aimed to design a novel form of selenium nanoparticles (Se NPs) functionalized with chitosan (Cs) and sialic acid to assess their antitumor effects on the human glioblastoma cell lines (T98 and A172). Se NPs were synthesized in the presence of chitosan and ascorbic acid (Vc) and the synthesis conditions were optimized using response surface methodology. Se NPs@Cs were obtained with a monoclinic structure with an average diameter of 23 nm under the optimum conditions (reaction time = 30 min, chitosan concentration = 1 % w/v, Vc/Se molar ratio = 5). To modify Se NP@Cs for glioblastoma treatment, sialic acid was used to cover the surface of the NPs. Sialic acid was successfully attached to the surface of Se NPs@Cs, and Se NPs@Cs-sialic acid were formed in the size range of 15-28 nm. Se NPs@Cs-sialic acid were stable for approximately 60 days at 4 ℃. The as-synthesized NPs exerted inhibitory effects on T98 greater than 3 T3 > A172 cells in a dose- and time-dependent manner. Additionally, sialic acid ameliorated the blood biocompatibility of Se NPs@Cs. Taken together, sialic acid improved both the stability and biological activity of Se NPs@Cs.

Polysaccharides from Spirulina platensis: Extraction methods, structural features and bioactivities diversity

Spirulina platensis, a well-known blue-green microalga cultivated and consumed in China and United States, is traditionally used as a food supplement and medical ingredient. Increasing evidence has confirmed that the Spirulina platensis polysaccharides (SPPs) are vital and representative pharmacologically active biomacromolecules and exhibit multiple health-promoting activities both in vivo and in vitro, such as those of anti-cancer, anti-oxidant, immunomodulatory, hypolipidemic and hypoglycemic, anti-thrombotic, anti-viral, regulation of the gut microbiota properties and other biological activity. The purpose of this review aims to comprehensively and systematically outline the extraction and purification methods, structural features, biological activities, underlying mechanisms, and toxicities of SPPs to support their potential utilization value in pharmaceuticals fields and functional foods. The structural and activities relationship of SPPs is also discussed. Besides, new valuable insights for future research with SPPs have also been proposed in the important areas of structural characterization and pharmacological activities.

Conferring of Drought and Heat Stress Tolerance in Wheat (Triticum aestivum L.) Genotypes and Their Response to Selenium Nanoparticles Application

In this study, the role of selenium nanoparticles (SeNPs, 10 mg·L^-1) has been investigated in modulating the negative effects of drought and heat stresses on eight bread wheat (Triticum aestivum L.) genotype seedlings. Those genotypes included Giza-168, Giza-171, Misr-1, Misr-3, Shandweel-1, Sids-1, Sids-12, and Sids-14. The study included six treatments as follows: regular irrigation with 100% Field Capacity (FC) at a temperature of 23 ± 3 °C (T1), drought stress with 60% FC (T2), heat stress of 38 °C for 5 h·day^-1 (T3), foliar spray of 10 mg·L^-1 of SeNPs only (T4), a combination of drought stress with foliar spray of 10 mg·L^-1 of SeNPs (T5), and heat stress with foliar spray of 10 mg·L^-1 of SeNPs (T6). The experiment continued for 31 days. Foliar application of SeNPs improved the plant growth, morpho-physiological and biochemical responses, and expression of stress-responsive genes in wheat (T. aestivum L.) seedlings. Overall, morpho-physiological traits such as plant height (PH), shoot fresh weight (SFW), shoot dry weight (SDW), root fresh weight (RFW), and root dry weight (RDW) of wheat genotypes grown under different conditions ranged from 25.37-51.51 cm, 3.29-5.15 g, 0.50-1.97 g, 0.72-4.21 g, and 0.11-1.23 g, respectively. From the morpho-physiological perspective, drought stress had a greater detrimental impact on wheat plants than heat stress, whereas heat stress significantly impacted the expression of stress-responsive genes. Stress responses to drought and heat varied between wheat genotypes, suggesting that different genotypes are more resilient to stress. Exogenous spraying of 10 mg·L^-1 of SeNPs improved the photosynthetic pigments, photosynthetic rate, gas exchange, and transpiration rate of wheat plants and enhanced drought and heat tolerance by increasing the activity of antioxidant enzymes including catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) and the expression level of stress-responsive genes. Our results showed that spraying wheat seedlings with 10 mg·L^-1 of SeNPs enhanced SOD activity for all genotypes as compared to the control, with the Sids-12 genotype having the highest value (196.43 U·mg^-1 FW·min^-1) and the Giza-168 genotype having the lowest (152.30 U·mg^-1 FW·min^-1). The expression of PIP1, LEA-1, HSP70, and HSP90 stress-responsive genes was more significant in tolerant genotypes (Giza-171 and Giza-168) than in sensitive ones (Misr-1 and Misr-3) in response to drought and heat stresses. Under stress conditions, the shoot and root fresh weights, photosynthetic pigment content, stomatal conductance (SC), and transpiration rate (TR) were positively correlated with plant height (PH), while root and shoot dry weights, malondialdehyde (MDA), proline, hydrogen peroxide (H₂O₂), and APX were negatively correlated. Multivariate analysis and biplot results revealed that genotypes Giza-168, Giza-171, Sids-12, and Sids-14 performed well in both stress situations and were classified as stress-tolerant genotypes. These best genotypes may be employed in future breeding projects as tools to face climate change. This study concluded that various physio-biochemicals and gene expression attributes under drought and heat stress could be modulated by foliar application of SeNPs in wheat genotypes, potentially alleviating the adverse effects of drought and heat stress.

Effects of Schisandra chinensis Polysaccharide-Conjugated Selenium Nanoparticles on Intestinal Injury in Mice

Schisandra chinensis polysaccharide (SCP) is an experimental therapeutic for the treatment of intestinal injury. Selenium nanoparticle modification can improve the bioactivity of polysaccharides. In this study, SCP was firstly extracted and purified by a DEAE-52 column, then SCP-Selenium nanoparticles (SCP-Se NPs) were prepared, and the procedure was optimized. Thereafter, the obtained SCP-Se NPs were characterized by transmission electron microscope, X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The influence of different storage environments on the stability of colloidal SCP-Se NPs was also investigated. Finally, the therapeutic effects of SCP-Se NPs on LPS-induced intestinal inflammatory injuries in mice were evaluated. Results showed that the optimized SCP-Se NPs were amorphous, uniform, spherical particles with a diameter of 121 nm, and the colloidal solution was stable at 4 °C for at least 14 d. Moreover, SCP-Se NPs could more effectively alleviate LPS-induced diarrhea, intestinal tissue injury, and tight junction destruction and decrease the elevated expression levels of TNF-α, IL-1β, and IL-6 compared with SCP. These results demonstrate that SCP-Se NPs may alleviate LPS-induced enteritis through their anti-inflammatory effects, indicating that SCP-Se NPs can serve as a good candidate for preventing and treating enteritis in the livestock and poultry industry.

Stabilization of Antioxidant and Anti-Inflammatory Activities of Nano-Selenium Using Anoectochilus burmannicus Extract as a Potential Novel Functional Ingredient

Anoectochilus burmannicus is an orchid that contains phenolic compounds and exhibits antioxidant and anti-inflammation properties. This study aimed to investigate whether its ethanolic extract (ABE) can be used as a reducing agent and/or a stabilizer of nano-selenium (SeNP) synthesis. SeNPs exhibited higher antioxidant activity than ABE-SeNPs. In contrast, ABE-SeNP (4 µM Se) had greater anti-inflammatory activity in LPS-induced macrophages than SeNPs. Interestingly, ABE acted as a stabilizer for SeNPs by preventing particle aggregation and preserving its antioxidant activity after long-term storage (90 days). Moreover, after the freeze-drying process, ABE-SeNPs could be completely reconstituted to suspension with significantly stable antioxidant and anti-inflammatory activities compared to freshly prepared particles, suggesting the cryoprotectant and/or lyoprotectant role of ABE. The present study shows the potential of ABE as an effective stabilizer for nanoparticles and provides evidence for the development of ABE-SeNPs as a food supplement or novel functional ingredient for health benefits.

Preparation of nano-selenium from chestnut polysaccharide and characterization of its antioxidant activity

Chestnut is widely cultivated and has high nutritional value due to its richness in polysaccharides. In order to improve the antioxidant activity of chestnut polysaccharide, chestnut polysaccharide (CP) was extracted by ultrasonic-assisted water extraction and alcohol precipitation and purified by cellulose DEAE-52 exchange and Sephadex G-100 chromatography in this study. CP isolates were characterized by I₂-KI reaction, three-strand helical structure analysis, infrared spectrum analysis, and nuclear magnetic resonance detection. The results showed that CP is a pyrylan sugar with triple helical structure and connected by α-glycosidic bonds, with sugar residues 1,4-α-D-Glcp, 1,6-α-D-Galp, 1,5-α-L-Araf, 1,4-α-L-Rhap, and 1,4-β-D-Glcp in the CP backbone. After purification, the branching structure, rod, and spherical structure were significantly increased, with reduced lamellar structure. The in vitro scavenging rates of CP at 10 mg·mL^-1 against DPPH, hydroxyl radicals, and ABTS were 88.95, 41.38, and 48.16%, respectively. The DPPH free radical scavenging rate of purified polysaccharide fraction CP-1a was slightly enhanced, and the other rates showed a small decrease. Selenized chestnut polysaccharide (CP-Se) was prepared using nano-selenium method. The selenization method was optimized and stable Se-CP was obtained. When the concentration was 5 mg·mL^-1, Se-CP had significantly higher scavenging abilities 89.81 ± 2.33, 58.50 ± 1.60, and 40.66 ± 1.91% for DPPH, hydroxyl radical, and ABTS radicals, respectively, than those of CP. The results of this study provide insight into the effects purification and selenization of chestnut polysaccharide on antioxidant activity, and also provide a theoretical basis for the development of chestnut polysaccharide for use in functional foods or health products.

Allotropy of selenium nanoparticles: Colourful transition, synthesis, and biotechnological applications

Elemental selenium (Se⁰ ) nanomaterials undergo allotropic transition from thermodynamically-unstable to more stable phases. This process is significantly different when Se⁰ nanoparticles (NPs) are produced via physico-chemical and biological pathways. While the allotropic transition of physico-chemically synthesized Se⁰ is fast (minutes to hours), the biogenic Se⁰ takes months to complete. The biopolymer layer covering biogenic Se⁰ NPs might be the main factor controlling this retardation, but this still remains an open question. Phylogenetically-diverse bacteria reduce selenium oxyanions to red amorphous Se⁰ allotrope, which has low market value. Then, red Se⁰ undergoes allotropic transition to trigonal (metallic grey) allotrope, the end product having important industrial applications (e.g. semiconductors, alloys). Is it not yet clear whether biogenic Se⁰ presents any biological function, or it is mainly a detoxification and respiratory by-product. The better understanding of this transition would benefit the recovery of Se⁰ NPs from secondary resources and its targeted utilization with respect to each allotropic stage. This review article presents and critically discusses the main physico-chemical methods and biosynthetic pathways of Se⁰ (bio)mineralization. In addition, the article proposes a conceptual model for the resource recovery potential of trigonal selenium nanomaterials in the context of circular economy.

Synthesis, Characterization of Low Molecular Weight Chitosan Selenium Nanoparticles and Its Effect on DSS-Induced Ulcerative Colitis in Mice

Selenium nanoparticles have attracted extensive attention due to their good bioavailability and activity. In the present study, a new form of selenium nanoparticle (Low molecular weight chitosan selenium nanoparticles (LCS-SeNPs)) were synthesized in a system of sodium selenite and acetic acid. The size, element state, morphology and elementary composition of LCS-SeNPs were characterized by using various spectroscopic and microscopic measurements. The protection of LCS-SeNPs against dextran sulfate sodium (DSS)-induced intestinal barrier dysfunction and the inherent mechanisms of this process were investigated. The results showed that LCS-SeNPs, with an average diameter of 198 nm, zero-valent and orange-red relatively uniform spherical particles were prepared. LCS-SeNPs were mainly composed of C, N, O and Se elements, of which Se accounted for 39.03% of the four elements C, N, O and Se. LCS-SeNPs reduced colon injury and inflammation symptoms and improved intestinal barrier dysfunction. LCS-SeNPs significantly reduced serum and colonic inflammatory cytokines TNF-α and IL-6 levels. Moreover, LCS-SeNPs remarkably increased antioxidant enzyme GSH-Px levels in serum and colonic tissue. Further studies on inflammatory pathways showed that LCS-SeNPs alleviated DSS-induced colitis through the NF-κB signaling pathway, and relieved inflammatory associated oxidative stress through the Nrf2 signaling pathway. Our findings suggested that LCS-SeNPs are a promising selenium species with potential applications in the treatment of oxidative stress related inflammatory intestinal diseases.

Progress in the Surface Functionalization of Selenium Nanoparticles and Their Potential Application in Cancer Therapy

As an essential micronutrient, selenium participates in numerous life processes and plays a key role in human health. In the past decade, selenium nanoparticles (SeNPs) have attracted great attention due to their excellent functionality for potential applications in pharmaceuticals. However, the utilization of SeNPs has been restricted by their instability and low targeting ability. Since the existing reviews mainly focused on the applications of SeNPs, this review highlights the synthesis of SeNPs and the strategies to improve their stability and targeting ability through surface functionalization. In addition, the utilization of functionalized SeNPs for the single and co-delivery of drugs or genes to achieve the combination of therapy are also presented, with the emphasis on the potential mechanism. The current challenges and prospects of functionalized SeNPs are also summarized. This review may provide valuable information for the design of novel functionalized SeNPs and promote their future application in cancer therapy.

Synthesis, characterization, in vitro antioxidant and hypoglycemic activities of selenium nanoparticles decorated with polysaccharides of Gracilaria lemaneiformis

Under a simple redox system of selenite and ascorbic acid, we used Gracilaria lemaneiformis polysaccharides (GLPs) as a stabilizer and dispersing agent to generate well-dispersed and stable selenium nanoparticles (SeNPs). The size, stability, morphology and physicochemical properties of GLPs-SeNPs were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared (FT-IR) spectra, energy dispersive X-ray (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Thermogravimetric (TG). The results showed that orange-red, amorphous, zero-valent and spherical GLPs-SeNPs with mean diameter of approximately 92.5 nm were successfully prepared, which exhibited good storage stability at 4 °C and remaining highly stable at different ion strengths and pH. The 2,2-diphenyl-1-pycrylhydrazyl (DPPH), 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and superoxide anion radical (O₂^•-) radical scavenging ability of GLPs-SeNPs were higher than those of bare SeNPs, GLPs and sodium selenite (Na₂SeO₃), and could reach 103.41%, 94.23%, 86% at a concentration of 1.5 mg/mL, respectively. Besides, GLPs-SeNPs also showed higher inhibitory effects on α-amylase and α-glucosidase. In vitro cytotoxicity assay and hemolysis activity examinations indicated that GLPs-SeNPs have excellent biocompatibility. Therefore, the GLPs-SeNPs might be used as a potential antioxidant agent and antidiabetic agent for food and medical applications.

Trace Element Selenium Effectively Alleviates Intestinal Diseases

Selenium (Se) is an essential trace element in the body. It is mainly used in the body in the form of selenoproteins and has a variety of biological functions. Intestinal diseases caused by chronic inflammation are among the most important threats to human health, and there is no complete cure at present. Due to its excellent antioxidant function, Se has been proven to be effective in alleviating intestinal diseases such as inflammatory bowel diseases (IBDs). Therefore, this paper introduces the role of Se and selenoproteins in the intestinal tract and the mechanism of their involvement in the mediation of intestinal diseases. In addition, it introduces the advantages and disadvantages of nano-Se as a new Se preparation and traditional Se supplement in the prevention and treatment of intestinal diseases, so as to provide a reference for the further exploration of the interaction between selenium and intestinal health.

Selenium Nanoparticles for Biomedical Applications: From Development and Characterization to Therapeutics

Selenium (Se) is an essential element to human health that can be obtained in nature through several sources. In the human body, it is incorporated into selenocysteine, an amino acid used to synthesize several selenoproteins, which have an active center usually dependent on the presence of Se. Although Se shows several beneficial properties in human health, it has also a narrow therapeutic window, and therefore the excessive intake of inorganic and organic Se-based compounds often leads to toxicity. Nanoparticles based on Se (SeNPs) are less toxic than inorganic and organic Se. They are both biocompatible and capable of effectively delivering combinations of payloads to specific cells following their functionalization with active targeting ligands. Herein, the main origin of Se intake, its role on the human body, and its primary biomedical applications are revised. Particular focus will be given to the main therapeutic targets that are explored for SeNPs in cancer therapies, discussing the different functionalization methodologies used to improve SeNPs stability, while enabling the extensive delivery of drug-loaded SeNP to tumor sites, thus avoiding off-target effects.