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1.
Chem Commun (Camb) ; 55(70): 10380-10383, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31397448

RESUMO

A strategy for the photoelectrochemical detection of miRNA with ultra-low background noise was developed using tungsten diselenide-cysteine-dopamine (WSe2/Cys/DA) as a nanoprobe coupled with mismatched catalytic hairpin assembly target recycling. A superior detection limit of 3.3 aM toward miRNA-221 was achieved.


Assuntos
Cisteína/química , Dopamina/química , Técnicas Eletroquímicas/métodos , MicroRNAs/análise , Sondas Moleculares/química , Nanoestruturas , Processos Fotoquímicos , Selênio/química , Tungstênio/química , Técnicas Biossensoriais , Catálise , Humanos , Limite de Detecção , MicroRNAs/sangue , Estudo de Prova de Conceito
2.
J Phys Chem A ; 123(28): 5995-6002, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31268326

RESUMO

High-resolution X-ray crystallography and two-dimensional NMR studies demonstrate that water-mediated conventional hydrogen-bonding interactions (N-H···N, O-H···N, etc.) bridging two or more amino acid residues contribute to the stability of proteins and protein-ligand complexes. In this work, we have investigated single water-mediated selenium hydrogen-bonding interactions (unconventional hydrogen-bonding) between amino acid residues in proteins through extensive protein data bank (PDB) analysis coupled with gas-phase spectroscopy and quantum chemical calculation of a model complex consisting of indole, dimethyl selenide, and water. Here, indole and dimethyl selenide represent the amino acid residues tryptophan and selenomethionine, respectively. The current investigation demonstrates that the most stable structure of the model complex observed in the IR spectroscopy mimics single water-mediated selenium hydrogen-bonded structural motifs present in the crystal structures of proteins. The present work establishes that water-mediated Se hydrogen-bonding interactions are ubiquitous in proteins and the number of these interactions observed in the PDB is more than that of direct Se hydrogen-bonds present there.


Assuntos
Proteínas/química , Selênio/química , Água/química , Biologia Computacional , Cristalografia por Raios X , Bases de Dados de Proteínas , Ligações de Hidrogênio , Indóis/química , Ligantes , Modelos Moleculares , Compostos Organosselênicos/química , Teoria Quântica , Selenometionina/química , Espectrofotometria Infravermelho , Triptofano/química
3.
J Photochem Photobiol B ; 197: 111510, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31163288

RESUMO

Treatment of chronic lung infection becomes a great challenge due to the drug resistant bacteria. In this scenario, evolving a new drug based on lipid metal conjugation loaded with potential antibiotic provides better drug delivery. In this study, ciprofloxacin loaded selenium-lipid nanoparticle (CxLSENPs) is produced in a novel route and its antimicrobial properties were tested against clinically important Gram-negative P. aeruginosa. The synthesized CxLSENPs was characterized by biophysical techniques (UV, Fluorescence spectroscopy, Raman spectroscopy, FTIR, FESEM, HRTEM and Zeta potential). Raman spectra coupled with FTIR spectra confirmed the possible interaction of lipid components in the NPs. HRTEM analysis confirmed the spherical shape of NPs. CxLSENPs recorded greater antibacterial effects on P. aeruginosa. A drastic reduction in the count of P. aeruginosa was observed after treatment with CxLSENPs. In order to further confirm the antibacterial efficiency, the live/dead cell assay was carried out. Live/dead analysis helps us to investigate the viability of bacterial cells. The number of dead bacterial cells was significantly higher in CxLSENPs treated groups when compare to the control. Furthermore, CxLSENPs increased the antioxidant enzyme activities (SOD, GPx, CAT and LPO) in mouse and protected the liver damage from bacterial infection. This study concludes that the developed CxLSENPs might be employed as strong antimicrobial and antioxidant agents for treating lung infection or interstitial lung diseases.


Assuntos
Antibacterianos/química , Ciprofloxacino/química , Portadores de Fármacos/síntese química , Lipídeos/química , Nanopartículas/química , Selênio/química , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Antioxidantes/metabolismo , Infecções Bacterianas/microbiologia , Infecções Bacterianas/prevenção & controle , Catalase/metabolismo , Ciprofloxacino/farmacologia , Ciprofloxacino/uso terapêutico , Portadores de Fármacos/química , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Doenças Pulmonares Intersticiais/tratamento farmacológico , Doenças Pulmonares Intersticiais/microbiologia , Doenças Pulmonares Intersticiais/patologia , Masculino , Camundongos , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Superóxido Dismutase/metabolismo
4.
Anal Bioanal Chem ; 411(20): 5277-5285, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31161325

RESUMO

Rapid, highly sensitive detection of tau protein and other neurodegenerative biomarkers remains a significant hurdle for diagnostic tests for Alzheimer's disease. In this work, we developed a novel tyrosinase (TYR)-induced tau aptamer-tau-tau antibody (anti-tau) sandwich fluorescence immunoassay to detect tau protein that used dopamine (DA)-functionalized CuInS2/ZnS quantum dots as the fluorophore. CuInS2/ZnS core/shell quantum dots with high luminescence, low toxicity, and excellent biocompatibility were successfully fabricated and decorated with DA through amide conjugation. Meanwhile, TYR was conjugated with anti-tau by a click reaction. When DA-functionalized CuInS2/ZnS quantum dots were added to the sandwich system, TYR catalyzed the transformation of DA to dopamine quinone, which acted as an effective electron acceptor and triggered fluorescence quenching. The fluorescence intensity of the immunoassay based on DA-functionalized CuInS2/ZnS quantum dots shows good performance in terms of linearity with the logarithm of tau protein concentration, with a linear concentration range from 10 pM to 200 nM. This work is the first to use a TYR-induced fluorescence immunoassay for the rapid detection of tau protein, paving a new way for the detection of disease biomarkers. Graphical abstract.


Assuntos
Cobre/química , Imunofluorescência/métodos , Índio/química , Monofenol Mono-Oxigenase/química , Pontos Quânticos/química , Selênio/química , Sulfetos/química , Compostos de Zinco/química , Proteínas tau/análise , Cristalografia por Raios X , Dopamina/análogos & derivados , Dopamina/química , Microscopia Eletrônica de Transmissão , Análise Espectral/métodos
5.
Environ Pollut ; 251: 945-951, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31234261

RESUMO

The removals of arsenic and selenium pollutants are always urgent desires for the water security. In this study, both sorption and catalysis strategies were combined for the effective removals of As(V) and Se(VI) over magnetic graphene oxide sheets (GOs)-oxidized carbon nanotubes (OCNTs) hydrogels. The sorption behavior facilitated the operation of catalysis reactions, meanwhile, the catalytic reduction promoted the release of occupied sorption sites and then restarted a new sorption-catalysis cycle. The synergic effect of sorption and catalysis realized 258.2 mg g-1 for As(V) enrichment capacity on MPG2T1, and ultra-fast sorption and catalysis equilibriums were identified within 9 min. In the case of Se(VI), a moderate enrichment performance was observed to be 46.2 mg g-1. Similarly, the ultra-fast sorption and reduction of Se(VI) were realized within 2 min. In the competition experiments, only SO42-, SO32-, and HPO42- showed interference for As(V) and Se(VI) removals. These results testified the superiority of the synergy effect of sorption and catalysis, and the feasibility of 3D magnetic GOs-OCNTs hydrogel in practical implementations.


Assuntos
Arsênico/química , Grafite/química , Nanotubos de Carbono/química , Selênio/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Catálise , Hidrogéis/química
6.
Environ Sci Pollut Res Int ; 26(22): 22421-22430, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31154647

RESUMO

The synergistic effects of trace elements selenium (Se) and cadmium (Cd) are well known. But the reasons for the trending accumulation behavior in both trace elements are under debate in the scientific community. The present investigation was conducted to evaluate the impact of heat units on the accumulation behavior in two environments. Se and Cd were applied in three groups (T0; 0:0, T1; 0.4:1, T2; 1:2) mg kg-1. As the time of planting and heat units consumed by the crop to attain its physiological maturity appears to be different. The sunlight may contribute as an important manipulating factor for the accumulation of heavy metals in the plant. The results of the present study indicated that the behavior in the accumulation pattern of both elements appears to be distinct in the same material. The increased fertilizer treatment in soil bulk linearly increased the metal contents in rice grain. The studies between different plant parts disclosed panicle as the primary reservoir for Se and Cd accumulation. The plant sown earlier accumulates more Se than Cd while the plants uptake more Cd when sown 1 month later. The plant completes the critical developmental phases (tillering, heading, and flowering) within 20-30 days interval depending on the variety. But the late-sown plants complete these transitional phases within 9-10 days interval ultimately result in less utilization of heat units. These quick transitional changes may lead to the uptake of an ample amount of Cd contents in rice grain even at a low level of Cd stress (1 and 2 mg kg-1), making rice unsafe for edible purposes. The proper time of planting could be effective in timely acclimatization of Se and Cd sequestration and translocation in rice various components. Graphical Abstract.


Assuntos
Cádmio/análise , Grão Comestível/química , Fertilizantes/análise , Metais Pesados/análise , Oryza/efeitos dos fármacos , Selênio/análise , Transporte Biológico , Metais Pesados/química , Oryza/química , Selênio/química , Solo
7.
Environ Sci Pollut Res Int ; 26(21): 21609-21618, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31129892

RESUMO

Biochar (BC) and activated carbon (AC) were both produced from corn straw. Biochar-supported zerovalent iron (BC-ZVI) and activated carbon-supported zerovalent iron (AC-ZVI) were synthesized and applied for Se(IV)/Se(VI) removal. The sorption capacity of BC-ZVI for Se(IV) and Se(VI) was reported at 62.52 and 35.39 mg g-1, higher than that of AC-ZVI (56.02 and 33.24 mg g-1), respectively, due to its higher iron content and more positive charges. The spectroscopic analyses showed that Se(IV)/Se(VI) were reduced to Se(0)/Se(-II) of less toxicity and solubility. The effects of various factors such as pH, ionic strength, co-existing cations and anions, and natural organic matter (NOM) were also investigated. Ionic strength showed no significant effect on Se(IV)/Se(VI) removal, but pH was critical. The presence of NO3- and SO42- did not cause obvious inhibition to the removal, while PO43- inhibited the sorption capacity of BC-ZVI and AC-ZVI for Se(IV)/Se(VI) significantly. Common cations (K+, Ca2+, and Mg2+) were found to slightly enhance the removal, while NOM significantly decreased the sorption capacity of BC-ZVI and AC-ZVI for Se(IV)/Se(VI). Besides, NOM showed stronger inhibition effect on AC-ZVI than that on BC-ZVI. These results indicated that BC-ZVI, compared with AC-ZVI, could be a promising sorbent to remove Se(IV)/Se(VI) due to its low cost and high efficiency.


Assuntos
Carvão Vegetal , Ferro/química , Selênio/química , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio , Concentração Osmolar
8.
IET Nanobiotechnol ; 13(2): 214-218, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31051453

RESUMO

Selenium (Se) is a rare and essential element for the human body and other living organisms because of its role in the structure of several proteins and having anti-oxidant properties to reduce oxidative stress at cells. Some microorganisms can absorb Se oxyanions and convert them into zero-valent Se (Se0) in the nanoscale dimensions, which can be used for producing Se nanoparticles (SeNPs). In the present study, SeNPs were intracellularly biosynthesised by yeast Nematospora coryli, which is an inexpensive method and does not involve using materials hazardous for human and environment. The produced NPs were refined by a two-phase system and then characterised and identified by ultraviolet-visible, X-ray diffraction, X-ray fluorescence, transmission electron microscope, and Fourier transform infrared spectroscopy analyses. The structural analysis of biosynthesised SeNPs showed spherical-shaped NPs with size ranging from 50 to 250 nm. Also, extracted NPs were applied to explore their anti-candida and anti-oxidant activities. The results of this investigation confirm the biological properties of Se.


Assuntos
Antifúngicos/metabolismo , Antioxidantes/metabolismo , Nanopartículas/química , Saccharomycetales/metabolismo , Selênio/metabolismo , Antifúngicos/química , Antifúngicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Compostos de Bifenilo/análise , Compostos de Bifenilo/metabolismo , Candida/efeitos dos fármacos , Tamanho da Partícula , Picratos/análise , Picratos/metabolismo , Saccharomycetales/química , Selênio/química
9.
Environ Sci Pollut Res Int ; 26(21): 21828-21834, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31134545

RESUMO

The effect of selenium on excessive fatty acid-induced apoptosis and abnormal amino acid metabolism in the liver is well known, because it is an important site in the fatty acid metabolism pathway. However, the protective role of nano-elemental selenium (nano-Se) supplementation against hexavalent chromium (K2Cr2O7)-induced abnormal fatty acid metabolism has not been evaluated yet. Therefore, we conducted chicken experiments with different nano-Se supplementation doses to investigate the role of nano-Se against Cr(VI)-induced adverse effects. For this purpose, a total of 120 1-day-old chicks were randomly divided into control group, Cr(VI)-exposed group, protection group, treatment group, prevention group, and nano-Se control group. The results of RT-qPCR showed that the nano-Se supplementation notably downregulated (P < 0.01) the messenger RNA (mRNA) expression levels of fatty acid synthase (FASN), whereas nano-Se supplementation significantly upregulated (P < 0.01) the mRNA expression level of acyl-coenzyme A oxidase 1 (ACOX1) in chicken's liver at day 35 of the experiment. Similar results were further verified by western blot analysis. Moreover, nano-Se supplementation significantly enhanced and reduced the antibody expression levels of ACOX1 and FASN in immunohistochemical analysis, respectively. Thus, finally, it was concluded that nano-Se can alleviate K2Cr2O7-induced abnormal fatty acid metabolism in chicken's liver.


Assuntos
Galinhas/metabolismo , Cromo/toxicidade , Ácidos Graxos/metabolismo , Fígado/efeitos dos fármacos , Selênio/farmacologia , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Animais , Apoptose/efeitos dos fármacos , Suplementos Nutricionais , Ácido Graxo Sintase Tipo I/genética , Ácido Graxo Sintase Tipo I/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Nanopartículas/administração & dosagem , Nanopartículas/química , Substâncias Protetoras/farmacologia , Selênio/administração & dosagem , Selênio/química
10.
Chem Commun (Camb) ; 55(46): 6523-6526, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31099806

RESUMO

Cu2-xSe nanoparticles (Cu2-xSeNPs) were camouflaged with a red blood cell membrane (RBC) to create nanoparticles with improved biocompatibility, longer blood retention times, excellent absorption properties, superior photothermal conversion efficiency (67.2%) and singlet oxygen production capabilities for the synergistic photothermal and photodynamic therapy of cancer in the second near-infrared (NIR-II) window.


Assuntos
Antineoplásicos/uso terapêutico , Membrana Eritrocítica/química , Nanopartículas/uso terapêutico , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/síntese química , Antineoplásicos/efeitos da radiação , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Cobre/química , Temperatura Alta , Humanos , Hipertermia Induzida/métodos , Raios Infravermelhos , Camundongos , Nanopartículas/química , Nanopartículas/efeitos da radiação , Nanopartículas/toxicidade , Fotoquimioterapia/métodos , Células RAW 264.7 , Selênio/química , Oxigênio Singlete/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Chem Commun (Camb) ; 55(41): 5817-5820, 2019 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-31041939

RESUMO

A novel Au-Se nanoprobe with remarkable anti-interference ability for glutathione was developed for real-time in situ monitoring of the upstream and downstream regulatory relationship between uPA and MMP-9 proteins in the pathway.


Assuntos
Ouro/química , Metaloproteinase 9 da Matriz/análise , Nanoestruturas/química , Neoplasias/diagnóstico por imagem , Imagem Óptica/métodos , Selênio/química , Ativador de Plasminogênio Tipo Uroquinase/análise , Glutationa/química , Humanos , Células MCF-7 , Nanoestruturas/ultraestrutura , Neoplasias/enzimologia
12.
Chem Commun (Camb) ; 55(49): 7037-7040, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31143887

RESUMO

A π-extended red absorbing Se-rhodamine (Se-NR) was synthesised and characterized. By masking the amine of Se-NR as an azide, we successfully constructed a bio-orthogonally activatable photosensitizer (Se-NR-Az). Se-NR-Az was not photocytotoxic, but when activated by the Staudinger reaction, photocytotoxicity was restored.


Assuntos
Azidas/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Rodaminas/farmacologia , Selênio/farmacologia , Azidas/química , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Estrutura Molecular , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Rodaminas/química , Selênio/química , Relação Estrutura-Atividade
13.
Chemistry ; 25(36): 8513-8521, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31012517

RESUMO

Insulin analogues, mainstays in the modern treatment of diabetes mellitus, exemplify the utility of protein engineering in molecular pharmacology. Whereas chemical syntheses of the individual A and B chains were accomplished in the early 1960s, their combination to form native insulin remains inefficient because of competing disulfide pairing and aggregation. To overcome these limitations, we envisioned an alternative approach: pairwise substitution of cysteine residues with selenocysteine (Sec, U). To this end, CysA6 and CysA11 (which form the internal intrachain A6-A11 disulfide bridge) were each replaced with Sec. The A chain[C6U, C11U] variant was prepared by solid-phase peptide synthesis; while sulfitolysis of biosynthetic human insulin provided wild-type B chain-di-S-sulfonate. The presence of selenium atoms at these sites markedly enhanced the rate and fidelity of chain combination, thus solving a long-standing challenge in chemical insulin synthesis. The affinity of the Se-insulin analogue for the lectin-purified insulin receptor was indistinguishable from that of WT-insulin. Remarkably, the thermodynamic stability of the analogue at 25 °C, as inferred from guanidine denaturation studies, was augmented (ΔΔGu ≈0.8 kcal mol-1 ). In accordance with such enhanced stability, reductive unfolding of the Se-insulin analogue and resistance to enzymatic cleavage by Glu-C protease occurred four times more slowly than that of WT-insulin. 2D-NMR and X-ray crystallographic studies demonstrated a native-like three-dimensional structure in which the diselenide bridge was accommodated in the hydrophobic core without steric clash.


Assuntos
Dissulfetos/química , Insulina/química , Selênio/química , Cristalografia por Raios X , Cisteína/química , Humanos , Insulina/genética , Insulina/metabolismo , Ligação Proteica , Dobramento de Proteína , Estabilidade Proteica , Estrutura Terciária de Proteína , Receptor de Insulina/química , Receptor de Insulina/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Selenocisteína/química , Termodinâmica
14.
J Anim Sci ; 97(6): 2569-2582, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-30957833

RESUMO

The goal of this study was to test the hypothesis that sodium selenite (ISe), SEL-PLEX (OSe), vs. a 1:1 blend (MIX) of ISe and OSe in a basal vitamin-mineral mix would differentially affect serological and hepatic parameters of growing steers grazing toxic endophyte-infected tall fescue-mixed forage pasture. Predominately Angus steers (BW = 183 ± 34 kg) were randomly selected from herds of fall-calving cows grazing endophyte-infected tall fescue-mixed pasture and consuming vitamin-mineral mixes that contained 35 ppm Se as ISe, OSe, and MIX forms. Steers were weaned, depleted of Se for 98 d, and subjected to summer-long common grazing of an endophyte-infected tall fescue-mixed pasture (0.51 ppm total ergovaline + ergovalinine; 10.1 ha). Steers were assigned (n = 8 per treatment) to the same Se form treatments upon which they were raised. Se treatments were administered by daily top-dressing 85 g of vitamin-mineral mix onto 0.23 kg soyhulls, using in-pasture Calan gates. The PROC MIXED procedure of SAS was used to assess the effect of Se form treatments on serum parameters at day 0, 22, 43, 64, and 86. After slaughter, the effect of Se treatment on hepatic alkaline phosphatase (tissue nonspecific isoform, TNALP) mRNA, protein, and albumin protein content was assessed using the PROC GLM procedure of SAS. Fisher's protected LSD procedure was used to separate treatment means. Partial correlation analysis was used to evaluate the relationship among whole blood Se concentration and serum parameters, accounting for the effect of time. Across periods, MIX steers had more (P ≤ 0.04) serum albumin than OSe and ISe steers, respectively. However, the relative hepatic bovine serum albumin protein content was not affected (P = 0.28) by Se treatments. Serum alkaline phosphatase activity was greater (P ≤ 0.01) in MIX and OSe steers. Similarly, hepatic TNALP protein content in MIX steers was greater (P = 0.01) than ISe steers. Partial correlation analysis revealed that serum albumin, blood urea nitrogen, and alkaline phosphatase activity were correlated (r ≥ 0.23, P ≤ 0.02) with whole blood Se concentration. In summary, consumption of 3 mg Se/d as OSe or MIX forms of Se in vitamin-mineral mixes increased serum albumin concentration and alkaline phosphatase activity, the reduction of which is associated with fescue toxicosis. We conclude that the organic forms of Se ameliorated the depression of 2 of known serological biomarkers of fescue toxicosis.


Assuntos
Ração Animal/análise , Doenças dos Bovinos/prevenção & controle , Bovinos/fisiologia , Endófitos/fisiologia , Festuca/microbiologia , Selênio/química , Fosfatase Alcalina/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Animais , Nitrogênio da Ureia Sanguínea , Fígado/metabolismo , Masculino , Minerais/química , Distribuição Aleatória , Estações do Ano , Selênio/farmacologia , Albumina Sérica/efeitos dos fármacos , Selenito de Sódio/química , Selenito de Sódio/farmacologia , Ureia/metabolismo , Vitaminas/química , Vitaminas/metabolismo
15.
Int J Mol Sci ; 20(8)2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-31022831

RESUMO

The modulation of the photophysical properties of a series of recently synthetized oxobacteriochlorins with the introduction of heavy atoms in the macrocycles, was investigated at density functional level of theory and by means of the time-dependent TDDFT formulation. Absorption frequencies, singlet-triplet energy gaps and spin-orbit coupling (SOC) constants values were computed for all the investigated compounds. Results show how the sulfur- selenium- and iodine-substituted compounds possess improved properties that make them suitable for application in photodynamic therapy (PDT).


Assuntos
Iodo/química , Fármacos Fotossensibilizantes/química , Porfirinas/química , Selênio/química , Enxofre/química , Desenho de Drogas , Modelos Moleculares , Fotoquimioterapia , Teoria Quântica
16.
IET Nanobiotechnol ; 13(1): 30-35, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30964034

RESUMO

This study was designed to evaluate and compare the stability, antioxidant and anticancer activities of selenium nanoparticles (SeNPs) decorated with different molecular weight (MW) of chitosan (CS) (1500 Da, 48 kDa, 510 kDa). The size range of well-dispersed SeNPs was effectively controlled by I- first and then coated with CS. The morphology, size and surface charge of generated SeNPs were characterised by several technologies. Fourier transform infrared spectroscopy was used to investigate the relationship between SeNPs and CS. SeNPs decorated with CS (510 kDa) can keep stable for more than 45 days. As observed from the results of a simple photometric system, the antioxidant activities of decorated SeNPs were enhanced compared to undecorated SeNPs. SeNPs coated with higher MW of CS (510 kDa) showed the strongest antioxidant activities. Moreover, the treatments of SeNPs decorated with CS inhibited the growth of HepG2 cells in a time- and dose-dependent manner. The proposed results demonstrated the critical roles of the MW of CS on the stability, antioxidant and anticancer properties of CS-coated SeNPs, which provided an important design cue for future applications of functional foods and additives.


Assuntos
Antineoplásicos , Antioxidantes , Quitosana , Nanopartículas/química , Selênio , Antineoplásicos/química , Antineoplásicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Quitosana/farmacologia , Células Hep G2 , Humanos , Peso Molecular , Selênio/química , Selênio/farmacologia
17.
Molecules ; 24(7)2019 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-30959902

RESUMO

Polysulfides (H2Sx) represent a class of reactive sulfur species (RSS) which includes molecules such as H2S2, H2S3, H2S4, and H2S5, and whose presence and impact in biological systems, when compared to other sulfur compounds, has only recently attracted the wider attention of researchers. Studies in this field have revealed a facet-rich chemistry and biological activity associated with such chemically simple, still unusual inorganic molecules. Despite their chemical simplicity, these inorganic species, as reductants and oxidants, metal binders, surfactant-like "cork screws" for membranes, components of perthiol signalling and reservoirs for inorganic hydrogen sulfide (H2S), are at the centre of complicated formation and transformation pathways which affect numerous cellular processes. Starting from their chemistry, the hidden presence and various roles of polysulfides in biology may become more apparent, despite their lack of clear analytical fingerprints and often murky biochemical footprints. Indeed, the biological chemistry of H2Sx follows many unexplored paths and today, the relationship between H2S and its oxidized H2Sx species needs to be clarified as a matter of "unmistaken identity". Simultaneously, emerging species, such as HSSeSH and SenS8-n, also need to be considered in earnest.


Assuntos
Selênio/química , Sulfetos/química , Enxofre/química , Sulfeto de Hidrogênio/química , Nanopartículas/química , Oxirredução , Análise Espectral , Compostos de Enxofre/química
18.
Nanoscale ; 11(16): 7600-7608, 2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-30968107

RESUMO

The treatment of malignant glioblastoma is a huge challenge due to the existence of the blood-brain barrier. Herein, we report the treatment of orthotopic malignant glioblastoma with imaging guided second near-infrared (NIR-II) photodynamic therapy and chemotherapy by using drug-loaded ultra-small Cu2-xSe theranostic nanoparticles (NPs). Ultra-small Cu2-xSe NPs possess a strong absorbance in the NIR-II window, and their absorption at 1064 nm is around 2 times that at 808 nm. Their strong NIR-II absorbance and the deeper-tissue penetration of NIR-II light ensure excellent photodynamic therapy performance under irradiation with a 1064 nm laser. We also demonstrate that ultra-small Cu2-xSe NPs can produce vast amounts of reactive oxygen species via electron transfer (for ˙OH generation) and energy transfer (for 1O2 generation) mechanisms under irradiation. In addition, these NPs can be effectively and locally transported into orthotopic malignant glioblastoma with the assistance of focused ultrasound. The deposited Cu2-xSe NPs can be used for photoacoustic imaging to guide the combined NIR-II photodynamic therapy and chemotherapy. The results show that the tumor growth can be significantly suppressed. This work demonstrates the great potential of drug-loaded ultra-small Cu2-xSe NPs as a promising therapeutic agent for the treatment of orthotopic malignant glioblastoma.


Assuntos
Cobre/química , Raios Infravermelhos , Nanopartículas/química , Selênio/química , Animais , Encéfalo/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Glioblastoma/tratamento farmacológico , Glioblastoma/mortalidade , Glioblastoma/patologia , Humanos , Camundongos , Camundongos Nus , Nanopartículas/uso terapêutico , Nanopartículas/toxicidade , Fotoquimioterapia , Oxigênio Singlete/química , Oxigênio Singlete/metabolismo , Taxa de Sobrevida , Transplante Heterólogo
19.
Molecules ; 24(7)2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30987088

RESUMO

Selenium is a micronutrient that is essential for the proper functioning of all organisms. Studies on the functions of selenium are rapidly developing. This element is a cofactor of many enzymes, for example, glutathione peroxidase or thioredoxin reductase. Insufficient supplementation of this element results in the increased risk of developing many chronic degenerative diseases. Selenium is important for the protection against oxidative stress, demonstrating the highest activity as a free radical scavenger and anti-cancer agent. In food, it is present in organic forms, as exemplified by selenomethionine and selenocysteine. In dietary supplementation, the inorganic forms of selenium (selenite and selenate) are used. Organic compounds are more easily absorbed by human organisms in comparison with inorganic compounds. Currently, selenium is considered an essential trace element of fundamental importance for human health. Extreme selenium deficiencies are widespread among people all over the world. Therefore, it is essential to supplement the deficiency of this micronutrient with selenium-enriched food or yeast cell biomass in the diet.


Assuntos
Análise de Alimentos , Micronutrientes , Selênio , Fenômenos Químicos , Dieta , Suplementos Nutricionais , Monitoramento Ambiental , Humanos , Micronutrientes/química , Selênio/química , Oligoelementos
20.
Environ Pollut ; 249: 647-654, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30933762

RESUMO

Rice grain is known to accumulate methylmercury (MeHg) and has been confirmed to be the major pathway of MeHg exposure to residents in mercury (Hg) mining areas in China. Selenium (Se) supplementation has been proven to be effective in mitigating the toxicity of Hg. To understand how Se supplementation influences soil Hg speciation, a wide range of Se (0-500 mg/kg) was applied to Hg polluted paddy soils in this study, which decreased MeHg concentration in soil from 2.95 ±â€¯0.36 to 0.69 ±â€¯0.16 µg/kg (or 77%). After Se addition, humic acid state Hg (F4) was transformed into strong-complexed state Hg (F5), indicating that Hg bound up to the non-sulfur functional groups of humic acid (non-RSH) was released and reabsorbed by strong binding Se functional group (F5). As a result, inorganic Hg (IHg) was reduced by >48%, 18%, and 80% in root, stem, and grain, respectively, however, the reduction was not apparent in leaf. Substantial reductions were also found for MeHg in grain and root, but not in stem and leaf. Soil is suggested to be the main source of both MeHg and IHg in rice grain. Such a finding may provide an idea for improving Hg-polluted paddies through controlling soil IHg and MeHg. Further research on the molecular structure of the strong-complexed Hg in F5 should be conducted to elucidate the mechanism of Hg-Se antagonism.


Assuntos
Compostos de Mercúrio/análise , Mercúrio/análise , Compostos de Metilmercúrio/análise , Oryza/efeitos dos fármacos , Selênio/química , Poluentes do Solo/análise , Transporte Biológico , China , Grão Comestível/química , Substâncias Húmicas/análise , Compostos de Mercúrio/metabolismo , Compostos de Metilmercúrio/metabolismo , Mineração , Oryza/metabolismo , Estruturas Vegetais/metabolismo , Selênio/farmacologia , Solo/química
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