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•Binding selenium nanoparticles with specific ligands helps in specificity.•Size, dose and chemical form are important determinants in the chemoprevention.•Enhanced anti-tumor ...activity when being conjugated to anti-tumor drug.•The fate of the nanoparticle depends on the physicochemical and its chemical properties.•Cytotoxicity mainly due to apoptosis or cause cell cycle arrest being induced.
Selenium nanoparticles have at present picked up a vital prospect in the field of medicine, due to their inquisitive properties when compared to other selenium compounds. They are comparatively better as anticancer, non- toxic, and biocompatible operators than selenite (SeO3−2) and selenate (SeO4−2) compounds. The mechanism behind the anticancerous property of SeNps is primarily due to the invasion of the apoptotic pathways and cell cycle arrest, which eventually lead to blockage of other pathways. Conjugation or surface modification of selenium nanoparticles enhances its anticancer adequacy by antibiotics, biomolecules or phytochemical compounds present in microbes or plants. Selenium, being an integral part of enzyme like glutathione peroxidase (GPx) and other seleno-chemical compounds, can enhance the chemotherapeutic activity by acting as a functional division of redox center and inhibiting the tissues from cellular damage by ROS. SeNps can open ways to new regular strategies for treating illnesses like malignancy, and this audit expresses the reasons why these nano measured medications can be the following huge achievement as chemotherapeutic operators.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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•Defective metal–organic frameworks (Zr6 MOFs) were prepared.•Selenium was removed by MOFs efficiently from aqueous solutions.•More efficient and faster uptake of Se(VI) was obtained ...with high defect densities.•DFT calculations evidenced the binding of Se(VI) via anion-exchange.•Defect-tunable MOFs are promising candidates for the elimination of heavy metal ions.
Hexanuclear zirconium metal–organic frameworks (Zr6 MOFs) were successfully designed to possess different kinds of defects with various contents and its important influence on the capture of Se(VI) oxyanions was studied. The displaceable ligands (aqua and hydroxy groups) and weak-binding “capping” ligands (Cl−, O2C-CH3−, O2C-CF3− or O2C-CHF2−, HO− and/or H2O) on Zr6 nodes could be substituted by Se(VI) oxyanions via a mechanism of anion-exchange. More efficient and faster uptake of Se(VI) oxyanions was obtained with the increase of the densities of both missing linker defects and missing cluster defects. Experimental findings as well as theoretical density functional theory (DFT) calculations disclosed that smaller HO−, Cl−, or H2O compensating ligands can be more easily substituted than the O2C-CH3−, O2C-CF3− or O2C-CHF2− compensating ligands. Based on DFT calculations, the binding energy of Se(VI) oxyanions toward defective UiO-66 is much higher than that of other heavy metals toward MOFs. Moreover, using modulator synthetic strategy in the preparation of Zr6 MOFs can be a better choice for enhancing the removal capacity than synthesizing them with longer organic linkers which are too complex and expensive. The experimental results and theoretical calculations prefigure the great potentials of defect-tunable MOFs as promising candidates in the application of heavy metal ion remediation because they can be synthesized in large scale at low price and can also be elegantly tailored.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•We analyse the potential broccoli enriched with selenium to a functional food.•Broccoli has significant antioxidant and antiproliferative activities.•Biofortification increased the amount of ...phenolic compounds and antioxidant activity.•The activities studied are influenced by the development of broccoli.•The broccoli seedlings had higher antioxidant and anti-proliferative activity.
In this work, three different broccoli maturity stages subjected to biofortification with selenium were evaluated for antioxidant and antiproliferative activities. Antioxidant trials have shown that the maturation stages biofortified with selenium had significantly higher amounts of phenolic compounds and antioxidant activity, especially seedlings. Although non-polar extracts of all samples show antiproliferative activity, the extract of broccoli seedlings biofortified with selenium stood out, presenting cytocidal activity for a glioma line (U251, GI50 28.5mgL−1).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Selenium nanoparticles (SeNPs) are gaining importance in the field of medicine owing to their antibacterial and anticancer properties. SeNPs are biocompatible and non-toxic compared to the ...counterparts, selenite (SeO₃ ⁻²) and selenate (SeO₄ ⁻²). They can be synthesized by physical, chemical, and biological methods and have distinct bright orange-red color. Biogenic SeNPs are stable and do not aggregate owing to natural coating of the biomolecules. Various hypotheses have been proposed to describe the mechanism of microbial synthesis of SeNPs. It is primarily a two-step reduction process from SeO₄ ⁻² to SeO₃ ⁻² to insoluble elemental selenium (Se⁰) catalyzed by selenate and selenite reductases. Phenazine-1-carboxylic acid and glutathione are involved in selenite reduction. Se factor A (SefA) and metalloid reductase Rar A present on the surface of SeNPs confer stability to the nanoparticles. SeNPs act as potent chemopreventive and chemotherapeutic agents. Conjugation with antibiotics enhances their anticancer efficacy. These also have applications in nanobiosensors and environmental remediation.
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CEKLJ, DOBA, EMUNI, FZAB, GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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•Ultrasonic fabrication of MgO nanosheets by an one-step ultrasonic method.•Both Se(IV) and Se(VI) adsorption by MgO nanosheets from aqueous solutions.•High adsorption Qmax for Se(IV) ...(103.52mgg−1) and Se(VI) (10.28mgg−1).•Inner-sphere surface complexes formation (SeO32−/SeO42−) on the surface of MgO nanosheets.
MgO nanosheets with thickness ranges of 3–10 molecule layers and high specific area (166.44m2g−1) were successfully fabricated by an ultrasound-assisted exfoliation method and used as adsorbent for the removal of both selenite (Se(IV)) and selenate (Se(VI)) from aqueous solutions. The resulting MgO nanosheets displayed high maximum adsorption capacities of 103.52 and 10.28mgg−1 for Se(IV) and Se(VI), respectively. ATR-FTIR and XPS spectroscopic results suggested that both Se(IV) and Se(VI) formed inner-sphere surface complexes on MgO nanosheets under the present experimental conditions. Furthermore, high adsorption capacity for Se(IV/VI) in the presence of coexistent anions (SO42−, PO43−, Cl−, and F−) and efficient regeneratability of adsorbent by NaOH solution were observed in the competitive adsorption and regeneration steps. The simple one-step synthesis process of MgO nanosheets and high adsorption capacities offer a promising method for Se(IV/VI) removal in water treatment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Selenate (SeO4 2–) bioreduction is possible with oxidation of a range of organic or inorganic electron donors, but it never has been reported with methane gas (CH4) as the electron donor. In this ...study, we achieved complete SeO4 2– bioreduction in a membrane biofilm reactor (MBfR) using CH4 as the sole added electron donor. The introduction of nitrate (NO3 –) slightly inhibited SeO4 2– reduction, but the two oxyanions were simultaneously reduced, even when the supply rate of CH4 was limited. The main SeO4 2–-reduction product was nanospherical Se0, which was identified by scanning electron microscopy coupled to energy dispersive X-ray analysis (SEM-EDS). Community analysis provided evidence for two mechanisms for SeO4 2– bioreduction in the CH4-based MBfR: a single methanotrophic genus, such as Methylomonas, performed CH4 oxidation directly coupled to SeO4 2– reduction, and a methanotroph oxidized CH4 to form organic metabolites that were electron donors for a synergistic SeO4 2–-reducing bacterium.
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IJS, KILJ, NUK, PNG, UL, UM
Anaerobic oxidation of methane (AOM) plays a crucial role in controlling the flux of methane from anoxic environments. Sulfate-, nitrite-, nitrate-, and iron-dependent methane oxidation processes ...have been considered to be responsible for the AOM activities in anoxic niches. We report that nitrate-reducing AOM microorganisms, enriched in a membrane biofilm bioreactor, are able to couple selenate reduction to AOM. According to ion chromatography, X-ray photoelectron spectroscopy, and long-term bioreactor performance, we reveal that soluble selenate was reduced to nanoparticle elemental selenium. High-throughput 16S rRNA gene sequencing indicates that Candidatus Methanoperedens and Candidatus Methylomirabilis remained the only known methane-oxidizing microorganisms after nitrate was switched to selenate, suggesting that these organisms could couple anaerobic methane oxidation to selenate reduction. Our findings suggest a possible link between the biogeochemical selenium and methane cycles.
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IJS, KILJ, NUK, PNG, UL, UM
•Foliar pretreatment with selenate increased Se content in pink tomato fruit.•Se treatment elevated sugars, amino acids and bioactive substances in fruit.•Quantitative proteomic approach was used to ...identify Se responsive proteins.•Se treatment affected proteins involved in fruit primary and secondary metabolism.
In this work, the effects of selenium (Se) on the nutritional quality of tomato fruit were investigated. The results showed that application of 1 mg L−1 sodium selenate foliar spray increased Se content in the fruit without affecting other concentrations of other metals. Se treatment elevated the contents of soluble sugars (glucose and fructose), amino acids, and bioactive compounds, such as flavanoids, glutathione, vitamin C, and vitamin E, in pink tomato fruit. Proteomic analysis using isobaric tags for relative and absolute quantification was performed on tomato fruit at the commercial harvest stage. When comparing Se-enriched tomato fruit with the control group, we identified an aggregate of 269 differentially expressed proteins. Proteins involved in carbohydrate metabolism, amino acids metabolism, and secondary metabolism were highly affected by Se treatment. The results help elucidate the mechanism of Se treatment on improved nutritional quality of tomato fruit.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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•A. brasilense is able to efficiently reduce toxic selenite to Se0S0-nanoparticles.•Reduction was also possible in environmental waters supplemented with selenite.•Biogenic ...nanoparticles are Se8-nSn structured spheres, most likely Se6S2.•Se0S0- nanoparticles occur extracellularly with an average size of 400nm.•Se0S0-nanoparticles form a (destabilized) colloidal suspension (ζ-potential −18mV).
This study combines the interaction between the toxic oxyanions selenite and selenate and the plant growth promoting bacterium Azospirillum brasilense with a comprehensive characterization of the formed selenium particles. As selenium is an essential trace element, but also toxic in high concentrations, its state of occurrence in nature is of major concern. Growth of the bacterium was affected by selenite (1–5mM) only, observable as a prolonged growth lag-phase of 3days. Subsequently, selenite reduction occurred under aerobic conditions resulting in extracellularly formed insoluble Se0 particles. Complementary studies by microscopic and spectroscopic techniques revealed the particles to be homogeneous and stable Se8-nSn structured spheres with an average size of 400nm and highly negative surface charge of −18mV in the neutral pH range. As this is the first study showing Azospirillum brasilense being able to biotransform selenite to selenium particles containing a certain amount of sulfur, even if environmental waters supplemented with selenite were used, they may significantly contribute to the biogeochemical cycling of both elements in soil as well as to their soil-plant transfer. Therefore, microbial biotransformation of selenite under certain circumstances may be used for various bio-remediation and bio-technological applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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•Total Se content of L. edodes was ranked as selenite > selenate > Se yeast in different treatments.•The main Se speciation was SeMet in L. edodes regardless Se applied.•Se-enriched ...L. edodes is a good source of dietary Se and selenite is more valuable for its production.
Edible fungi have strong ability to transform inorganic Se into organic forms. Therefore, different concentrations of selenite, selenate and Se-yeast were injected as Se-supplements into substrates to produce Se-enriched Lentinula edodes. The Se content and its speciation distribution in the fruit bodies of L. edodes were analysed at different harvest times. Results indicate that Se concentrations of L. edodes increased first and then decreased over time. Based on Se accumulation in L. edodes, selenium use efficiency was ranked as selenite > selenate > Se-yeast. SeMet was the predominant Se speciation in the fruit bodies of L. edodes. SeMet made up the biggest proportion of total Se content and increased with application time for selenite and selenate treatments, whereas no significant change was found for Se-yeast treatment. This study demonstrates that Se-enriched L. edodes is a good source of dietary Se.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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