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1.
Chem Commun (Camb) ; 55(67): 9955-9958, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31364619

RESUMO

A silver nanocluster-based ratiometric fluorescent nanosensor was developed for the determination of ATP in the cerebrospinal fluid of a mouse brain. Using this useful tool with good stability and high selectivity as well as a wide linear detection range, it was found that the ATP concentration in a mouse brain with Alzheimer's disease was 2300-fold higher than that in a normal one.


Assuntos
Trifosfato de Adenosina/líquido cefalorraquidiano , Química Encefálica , DNA/química , Corantes Fluorescentes/química , Nanopartículas Metálicas/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Encéfalo/citologia , Encéfalo/patologia , Córtex Cerebral/química , Hipocampo/química , Camundongos , Conformação de Ácido Nucleico , Prata/química , Espectrometria de Fluorescência/métodos
2.
Chem Commun (Camb) ; 55(71): 10571-10574, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31417999

RESUMO

A portable dual-mode sensing platform based on a self-standing TiO2 nanotube membrane is developed for simultaneously performing both qualitative analysis by the naked eye and quantitative analysis by ionic current. This dual-mode diagnosis strategy exhibits a high performance in telomerase detection in urine specimens from patients with bladder cancer.


Assuntos
Nanotubos/química , Telomerase/urina , Titânio/química , Neoplasias da Bexiga Urinária/diagnóstico , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Cor , Ouro/química , Humanos , Membranas Artificiais , Nanopartículas Metálicas/química , Prata/química , Neoplasias da Bexiga Urinária/urina
3.
Phys Chem Chem Phys ; 21(35): 19288-19297, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31451821

RESUMO

This paper reports a facile, fast, and cost-effective method for the synthesis of three-dimensional (3D) porous AgNPs/Cu composites as SERS substrates for the super-sensitive and quantitative detection of food organic contaminations. Due to the 3D porous hotspot architecture and the strong plasmonic coupling between Ag and Cu, the porous AgNPs/Cu substrate achieves ultrasensitive detection of multiple analytes as low as 10-11 M (crystal violet, CV), 10-9 M (malachite green, MG), 10-11 M (acephate), and 10-9 M (thiram) even with a portable Raman device. Moreover, this 3D solid substrate has good signal uniformity (RSD < 11%) and superior stability (<14% signal loss), allowing for practical SERS detections. Importantly, by simply wiping the real sample surface using the substrate, it successfully detects CV and MG residues on crayfish, and the limit of detection (LOD) of CV and MG is determined to be 1.14 × 10-9 M and 0.94 × 10-7 M, respectively. Further, the substrate can also be applied to detect acephate on eggplant with a LOD of 1.41 × 10-9 M and thiram on an apple surface with a LOD of 1.04 × 10-7 M. Note that all these SERS detections on real samples have a broad dynamic concentration range and a good linear dependence. As a "proof of concept", multi-component detection on a real sample has also been demonstrated. This 3D solid substrate possesses excellent detection sensitivity, diversity, and accuracy, which allows rapid and reliable determination of toxic substances in foods.


Assuntos
Técnicas de Química Analítica/métodos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Praguicidas/análise , Análise Espectral Raman , Animais , Técnicas de Química Analítica/economia , Cobre/química , Limite de Detecção , Nanopartículas Metálicas/química , Reprodutibilidade dos Testes , Prata/química
4.
Pharm Res ; 36(10): 147, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31414240

RESUMO

PURPOSE: The aim was to design and thoroughly characterize monodisperse Fe3O4@SiO2-Ag nanoparticles with strong antibacterial properties, which makes them a candidate for targeting bacterial infections. METHODS: The monodisperse Fe3O4 nanoparticles were prepared by oleic acid-stabilized thermal decomposition of Fe(III) oleate; the particles were coated with silica shell using a water-in-oil reverse microemulsion, involving hydrolysis and condensation of tetramethyl orthosilicate. Resulting Fe3O4@SiO2 particles were modified by (3-mercaptopropyl)trimethoxysilane to introduce 1.1 mmol SH/g. Finally, the Fe3O4@SiO2-SH nanoparticles were decorated with silver nanoclusters formed by reduction of silver nitrate with NaBH4. The particles were analyzed by FTIR, X-ray photoelectron and atomic absorption spectroscopy, dynamic light scattering and vibrating sample magnetometry. The antibacterial activity of the Fe3O4@SiO2 and Fe3O4@SiO2-Ag nanoparticles was tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria cultivated on Luria agar plates or in Luria broth. RESULTS: The superparamagnetic Fe3O4@SiO2-Ag nanoparticles (21 nm in diameter; saturation magnetization 26 A∙m2/kg) were successfully obtained and characterized. Inhibitory and toxic effects against bacteria were documented by incubation of the Fe3O4@SiO2-Ag nanoparticles with Staphylococcus aureus and Escherichia coli. CONCLUSIONS: The combination of magnetic properties together with bactericidal effects is suitable for the disinfection of medical instruments, water purification, food packaging, etc.


Assuntos
Antibacterianos/química , Nanopartículas de Magnetita/química , Prata/química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Ácido Oleico/química , Tamanho da Partícula , Silanos/química , Dióxido de Silício/química , Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
5.
Food Chem ; 298: 125014, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260973

RESUMO

Natural red purple dye, Betanin, was extracted from the beetroot, purified by aqueous two- phase extraction and gel permeation column chromatography, and used as a reducing agent for the synthesis of silver-betanin core-shell triangular nanodisks for the first time. Spectroscopic data show that the nanoparticle structure is core@shell like with Ag as core and betanin as shell. Langmuir monolayer model (qm = 32.4 mg/g, RL = 0.99 and R2 = 0.997) was the best fit adsorption isotherm for the dye removal. Adsorption kinetics is well explained by pseudo-second-order equation. Gibbs free energy (ΔG0 = -2.59 kJ mol-1), enthalpy (ΔH0 = 18.05 kJ mol-1), and entropy (ΔS0 = 68.92 J/K/mol) were calculated and discussed. The antibacterial activity of betanin-AgNPs were determined against Escherichia coli MTCC-450 (E. coli) and Staphylococcus aureus MTCC-3160 (S. aureus) bacteria.


Assuntos
Antibacterianos/farmacologia , Beta vulgaris/química , Betacianinas/farmacologia , Corantes/farmacologia , Nanopartículas Metálicas/química , Prata/química , Adsorção , Antibacterianos/química , Betacianinas/química , Betacianinas/isolamento & purificação , Corantes/química , Corantes/isolamento & purificação , Entropia , Escherichia coli/efeitos dos fármacos , Cinética , Staphylococcus aureus/efeitos dos fármacos , Termodinâmica
6.
Chem Commun (Camb) ; 55(61): 8935-8938, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31286126

RESUMO

The Eubacterium saburreum serine protease inhibitor from the human gut microbiota inhibits the eukaryotic pancreatic elastase associated with acute pancreatitis. Interestingly, the inhibition efficiency and stability are markedly increased by the para-sulphonato-calix[8]arene capped silver nanoparticles. Moreover, this enzyme is distinguishable by its high inhibitory effect at broad pH range between 2-10 and temperatures from 10 to 40 °C, in the presence of para-sulphonato-calix[8]arene capped silver nanoparticles the enzyme remains active even at 70 °C.


Assuntos
Calixarenos/química , Nanopartículas Metálicas/química , Elastase Pancreática/antagonistas & inibidores , Serpinas/química , Prata/química , Sequência de Aminoácidos , Animais , Ensaios Enzimáticos , Eubacterium/química , Concentração de Íons de Hidrogênio , Estabilidade Proteica , Alinhamento de Sequência , Serpinas/isolamento & purificação , Ácidos Sulfônicos/química , Suínos , Temperatura Ambiente
7.
Chem Commun (Camb) ; 55(65): 9697-9700, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31347623

RESUMO

An ultra-high sensitivity sensor with the function of chiral signal amplification has been proposed for the enantiomer discrimination of various amino acid enantiomers based on charge transfer (CT)-induced SERS spectroscopy. The introduced TiO2 in this sensor improves the CT behavior and discrimination efficiency distinctly and enantiomeric discrimination is realized even at low concentration.


Assuntos
Compostos de Anilina/química , Nanopartículas Metálicas/química , Compostos de Sulfidrila/química , Triptofano/análise , beta-Ciclodextrinas/química , Ligações de Hidrogênio , Fenilalanina/análise , Fenilalanina/química , Prata/química , Análise Espectral Raman/métodos , Estereoisomerismo , Titânio/química , Triptofano/química , Tirosina/análise , Tirosina/química
8.
J Photochem Photobiol B ; 197: 111536, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31326846

RESUMO

The latent utilization of biomaterials that are osteo-conducive in the advancement of healing bone fracture has fascinated extensive consideration. This work includes the synthesis of silver nanoparticles (AgNPs) with the help of a Bauhinia acuminate plant flower extract through an ecofriendly synthetic process without any use of harmful reductants. In the fabrication of AgNPs, Bauhinia acuminate plant flower extract bio constituents acts as both stabilizing and reducing agent. The studies of Fourier transform infrared (FTIR) and X-ray diffraction (XRD) techniques confirmed the formation of AgNPS. TEM images revealed that AgNPs are uniform with average particle size of 17 nm. Further, this work explored if silver nanoparticles (AgNPs) might endorse the osteogenesis and proliferation of mesenchymal stem cells (MSCs) and advance the curing of bone fractures. We also exhibited that the prepared AgNPs could promote the in -vitro osteogenic differentiation and proliferation of MSCs'. Also, the prepared AgNps could stimulate the proliferation of mMSCs at specific concentrations of 6-20 µM. Further, cell viability studies showed that AgNPs exhibited no reduction in mouse mesenchymal stem cell viability at <4 µM. Further, these results indicated the induction effects of AgNPs on osteogenic differentiation and proliferation on MSCs, as well as the advancement of meniscus injury healing.


Assuntos
Bauhinia/química , Nanopartículas Metálicas/química , Osteogênese , Extratos Vegetais/química , Prata/química , Animais , Bauhinia/metabolismo , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Flores/química , Flores/metabolismo , Consolidação da Fratura/efeitos dos fármacos , Química Verde , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Nanopartículas Metálicas/toxicidade , Camundongos , Microscopia Eletrônica de Transmissão , Osteogênese/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier
9.
J Environ Radioact ; 208-209: 106017, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31325735

RESUMO

Silver (Ag)-based technologies are amongst the most common approaches to removing radioiodine from aqueous waste streams. As a result, a large worldwide inventory of radioactive AgI waste presently exits, which must be stabilized for final disposition. In this work, the efficacy of silver-impregnated granular activated carbon (Ag-GAC) to remove iodide (I-), iodate (IO3-) and organo-iodine (org-I) from cementitious leachate was examined. In addition, cementitious materials containing I-, IO3-, or org-I loaded Ag-GAC were characterized by iodine K-edge XANES and EXAFS to provide insight into iodine stability and speciation in these waste forms. The Ag-GAC was very effective at removing I- and org-I, but ineffective at removing IO3- from slag-free grout leachate under oxic conditions. I- or org-I removal was due to the formation of insoluble AgI(s) or Ag-org-I(s) on the Ag-GAC. When I--loaded Ag-GAC material was cured with slag-free and slag grouts, I- was released from AgI(s) to form a hydrated I- species. Conversely, when org-I loaded Ag-GAC material was cured in the two grout formulations, no change was observed in the iodine speciation, indicating the org-I species remained bound to the Ag. Because little IO3- was bound to the Ag-GAC, it was not detectable in the grout. Thus, grout formulation and I speciation in the waste stream can significantly influence the effectiveness of the long-term disposal of radioiodine associated with Ag-GAC in grout waste forms.


Assuntos
Carvão Vegetal/química , Radioisótopos do Iodo/química , Modelos Químicos , Prata/química , Iodetos
10.
Pestic Biochem Physiol ; 157: 45-52, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31153476

RESUMO

Herein, we describe the enhanced antifungal activity of silver nanoparticles biosynthesized by cell free filtrate of Trichoderma viride (MTCC 5661) in comparison to chemically synthesized silver nanoparticles (CSNP) of similar shape and size. Biosynthesized silver nanoparticles (BSNP) enhanced the reduction in dry weight by 20 and 48.8% of fungal pathogens Fusarium oxysporum and Alternaria brassicicola respectively in comparison to their chemical counterparts (CSNP). Nitroblue tetrazolium and Propidium iodide staining demonstrated the higher generation of superoxide radicals lead to higher death in BSNP treated fungus in comparison to CSNP. Scanning electron microscopy of A. brassicicola revealed the osmotic imbalance and membrane disintegrity to be major cause for fungal cell death after treatment with BSNP. To gain an insight into the mechanistic aspect of enhanced fungal cell death after treatment of BSNP in comparison to CSNP, stress responses and real time PCR analysis was carried out with A. brassicicola. It revealed that generation of ROS, downregulation of antioxidant machinery and oxidative enzymes, disruption of osmotic balance and cellular integrity, and loss of virulence are the mechanisms employed by BSNP which establishes them as superior antifungal agent than their chemical counterparts. With increasing drug resistance and ubiquitous presence of fungal pathogens in plant kingdom, BSNP bears the candidature for new generation of antifungal agent.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Nanopartículas Metálicas/química , Doenças das Plantas/microbiologia , Prata/química , Alternaria/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismo
11.
Carbohydr Polym ; 219: 290-297, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151528

RESUMO

Microbial contamination has evolved as a life-threatening problem afflicting people due to various diseases caused by pathogenic bacteria in drinking water. Thus developing novel antibacterial materials is an urgent need. Herein, a chitosan (CTS)/ biochar-nanosilver (C-Ag) antibacterial composite was prepared by a method of CTS-coated on C-Ag obtained through a facile high-temperature carbonization process using corn straw as the carbon substrate. The results from FT-IR, XRD, SEM and TG-DSC revealed that the biochar loading spherical silver nanoparticles was coated with CTS in the composite. The antibacterial activity of the CTS/C-Ag composite was investigated using the plate counting method with Escherichia coli (E. coli), and the results suggest that the composite exhibited excellent antibacterial activity against E. coli. In this application study, it was proven that the CTS/C-Ag composite exhibits sustainable antibacterial activity and good reusability for drinking water. Therefore, the CTS/C-Ag composite has potential application in drinking water treatment.


Assuntos
Antibacterianos , Quitosana/farmacologia , Água Potável , Escherichia coli/efeitos dos fármacos , Nanocompostos/química , Purificação da Água/métodos , Antibacterianos/química , Antibacterianos/farmacologia , Carvão Vegetal/química , Quitosana/química , Água Potável/análise , Água Potável/microbiologia , Nanopartículas Metálicas/química , Extratos Vegetais/química , Prata/química , Zea mays/química
12.
Pharm Res ; 36(8): 122, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31218556

RESUMO

PURPOSE: A non-propellant based foam (NPF) system was developed incorporating the antibiotics, pectin capped green nano-silver and sulfadiazine (SD) for the topical treatment of burn wounds as a convenient alternative to the existing therapies. METHODS: NPF were prepared using various surfactants and oils forming a nanoemulsion. Anti-microbial studies by resazurin microtitre assay, ex vivo diffusion, in vivo skin permeation and deposition studies, and acute irritation studies were carried out. NPF was applied onto secondary thermal wounds manifested on mice models followed by macroscopic and histological examinations. RESULTS: NPF had an average globule size of <75 nm. The viscosity was ~10 cP indicating the feasibility of expulsion from the container upon actuation. With no skin irritation, the foams showed a higher skin deposition of SD. A high contraction and an evident regeneration of the skin tissue upon treatment with NPF indicated a good recovery from the thermal injury was apparent from the histology studies. CONCLUSION: NPF represents an alternative topical formulation that can be employed as a safe and effective treatment modality for superficial second degree (partial thickness) burn wounds. With a minimal requirement of mechanical force, the no-touch application of NPF makes it suitable for sensitive and irritant skin surfaces.


Assuntos
Antibacterianos/farmacologia , Queimaduras/tratamento farmacológico , Nanopartículas Metálicas/química , Prata/química , Sulfadiazina/farmacologia , Cicatrização/efeitos dos fármacos , Administração Tópica , Animais , Antibacterianos/administração & dosagem , Queimaduras/patologia , Queimaduras/fisiopatologia , Composição de Medicamentos/métodos , Quimioterapia Combinada , Emulsões , Escherichia coli/efeitos dos fármacos , Química Verde , Humanos , Masculino , Camundongos , Óleos/química , Tamanho da Partícula , Permeabilidade , Pele/efeitos dos fármacos , Pele/patologia , Pele/fisiopatologia , Staphylococcus aureus/efeitos dos fármacos , Sulfadiazina/administração & dosagem , Tensoativos/química
13.
Anal Bioanal Chem ; 411(17): 3829-3838, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31172234

RESUMO

The rapid detection of bacterial strains has become a major topic thoroughly discussed across the biomedical field. Paired with the existence of nosocomial pathogen agents that imply extreme medical and financial challenges throughout diagnosis and treatment, the development of rapid and easy-to-use sensing devices has gained an increased amount of attention. Moreover, antibiotic resistance considered by World Health Organization as one of the "biggest threats to global health, food security, and development today" enables this topic as high priority. Pseudomonas aeruginosa, one of the most ubiquitous bacterial strains, has various quorum-sensing systems that are a direct cause of their virulence. One of them is represented by pyocyanin, a blue pigment with electroactive properties that is synthesized from early stages of bacterial colonization. Thus, the sensitive detection of this biomarker could enable a personalized and efficient therapy. It was achieved with the development of an electrochemical sensor based on a thermosensitive polymer, modified with Au/Ag nanoalloy for the rapid and accurate detection of pyocyanin, a virulence biomarker of Pseudomonas aeruginosa. The sensor displayed a linear range from 0.12 to 25 µM, and a limit of detection of 0.04 µM (signal/noise = 3). It was successfully tested in real samples spiked with the target analyte without any pretreatment other than a dilution step. The detection of pyocyanin with high recovery in whole blood in a time frame of 5-10 min from the moment of collection was performed with this electrochemical sensor. Graphical abstract.


Assuntos
Ligas/química , Ouro/química , Hidrogéis/química , Nanopartículas Metálicas/química , Piocianina/análise , Prata/química , Ágar/química , Artefatos , Biomarcadores/análise , Técnicas Biossensoriais , Técnicas Eletroquímicas/métodos , Limite de Detecção , Sistemas Automatizados de Assistência Junto ao Leito , Pseudomonas aeruginosa/isolamento & purificação , Piocianina/sangue , Reprodutibilidade dos Testes , Temperatura Ambiente
14.
Chem Commun (Camb) ; 55(56): 8076-8078, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31225560

RESUMO

We developed a novel "signal-on" photoelectrochemical (PEC) aptasensor with a near-zero background signal by using AgVO3 as a single photoactive material for the sensitive detection of vascular endothelial growth factor (VEGF165).


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas/métodos , Óxidos/química , Processos Fotoquímicos , Prata/química , Compostos de Vanádio/química , Fator A de Crescimento do Endotélio Vascular/análise , Humanos , Limite de Detecção
15.
Anal Bioanal Chem ; 411(20): 5023-5031, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31177332

RESUMO

A simple method to determine hazardous silver nanoparticles (AgNPs) based on ionic liquid (IL) dispersive liquid-liquid microextraction and back-extraction is described. This approach involves AgNP stabilization using a cationic surfactant followed by extraction from the sample matrix by means of an IL as an extraction phase. Certain ILs have high affinity for metals, and preliminary experiments showed that those ILs consisting of imidazolium cation efficiently extracted AgNPs in the presence of a cationic surfactant and a chelating agent. Afterward, histamine was used as a dispersing agent to promote phase transfer of differently coated AgNPs from the IL in aqueous solution to be subsequently analyzed by UV-visible spectrometry. The analytical procedure allows AgNPs to be recovered from the sample matrix in an aqueous medium, the enrichment factor being up to 4, preserving both AgNP size and AgNP shape as demonstrated by transmission electron microscopy images and the localized surface plasmon resonance band characteristic of each AgNP. The present method exhibited a linear response for AgNPs in the range from 3 to 20 µg/mL, the limit of detection being 0.15 µg/mL. Method efficiency was assessed in spiked orange juice and face cream, yielding recoveries ranging from 75.7% to 96.6%. The method was evaluated in the presence of other nanointerferents (namely, gold nanoparticles). On the basis of diverse electrophoretic mobilities and surface plasmon resonance bands for metal nanoparticles, capillary electrophoresis was used to prove the lack of interaction of the target AgNPs with gold nanoparticles during the whole protocol; thus, interferents do not affect AgNP determination. As a consequence, the analytical approach described has great potential for the analysis of engineered nanosilver in consumer products. Graphical abstract Simple protocol for the determination of silver nanoparticles (AgNPs) based on dispersive liquid-liquid extraction with a specific short alkyl side chain ionic liquid and their quantitative detection with a UV-visible spectrometer. HMIM•PF6 1-hexyl-3-methylimidazolium hexafluorophosphate, NP nanoparticle, SPR surface plasmon resonance.


Assuntos
Cosméticos/química , Sucos de Frutas e Vegetais/análise , Líquidos Iônicos/química , Microextração em Fase Líquida/métodos , Nanopartículas Metálicas/análise , Prata/química , Artefatos , Estudos de Viabilidade , Limite de Detecção , Nanopartículas Metálicas/química , Espectrofotometria Ultravioleta/métodos , Ressonância de Plasmônio de Superfície
16.
Int J Nanomedicine ; 14: 3427-3438, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190801

RESUMO

Background: Biogenic silver nanoparticles (AgNPs) have wider range of biomedical applications. The present work synthesized Tp-AgNPs using mycelial extract of endophytic fungus Talaromyces purpureogenus (MEEF), characterized, and analyzed for antibacterial, anti-proliferation and cell wounding healing activities. Methods: The synthesized Tp-AgNPs were characterized by UV-visible spectrophotometer (UV-Vis), field emission transmission electron microscopy (FETEM) with energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), particle size analysis (PSA) and X-ray diffraction (XRD). Further, antibacterial activity was determined by Kirby-Bauer test and anti-proliferation activity was tested in human lung carcinoma A549 by water-soluble tetrazolium and flow cytometer assay. In addition, cell wounding healing activity was determined by scratch assay. Results: UV-Vis results displayed a strong absorption peak from 390 nm to 420 nm, which indicated the successful synthesis of Tp-AgNPs. FETEM-EDS results indicated the round and triangle shaped Tp-AgNPs with the average size of 25 nm in accordance with PSA. FTIR analysis indicated the involvement of various functional molecules from MEEF in the synthesis of Tp-AgNPs. XRD result proved nature of Tp-AgNPs as a high-quality crystal. The Tp-AgNPs significantly inhibited the growth of bacterial pathogens at the minimal inhibitory concentration of 16.12 µg.mL-1 for Gram+, and 13.98 µg.mL-1 for Gram- bacteria. Further, Tp-AgNPs (2 µg.mL-1) showed a strong anti-proliferation effect in A549. Interestingly, Tp-AgNPs was not cytotoxic to normal NIH3T3 cells. In addition, the NPs exhibited a strong cell wounding healing activity. Conclusion: This work biosynthesized AgNPs with strong antibacterial, anticancer and cell wound healing properties using endophytic fungus T. purpureogenus.


Assuntos
Antibacterianos/farmacologia , Nanopartículas Metálicas/química , Prata/farmacologia , Talaromyces/metabolismo , Células A549 , Animais , Bactérias/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Sobrevivência Celular , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Humanos , Nanopartículas Metálicas/ultraestrutura , Camundongos , Testes de Sensibilidade Microbiana , Células NIH 3T3 , Prata/química , Cicatrização/efeitos dos fármacos
17.
J Photochem Photobiol B ; 197: 111529, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31220803

RESUMO

The therapeutic molecules recovered from the marine biological origin are widely used for the treatment of diverse levels of infections caused by microbial pathogens. In addition, the eco-friendly preparations of nanomaterials together with the secondary metabolites' producing active microbial strains effectively suppress the spreading of the pathogenic bacteria. Considering their importance, the present study evaluated the environmental friendly synthesis of Silver nitrate nanomaterials (SNM) from the active marine Streptomyces strain Al-Dhabi-91 isolated from the Dammam region of Saudi Arabia. The obtained SNM was chemically characterized by various spectroscopic techniques such as UV, XRD, FTIR, SEM, TEM and EDAX; and its biological applications such as antimicrobial properties and antioxidant potential were recorded by DPPH methods. Biochemical and micromorphological studies together with the molecular techniques confirmed that the isolate Al-Dhabi-91 belonged to Streptomyces species. The characterization techniques confirmed that the UV spectrum showed maximum absorption peak at 305 nm indicating the plasmodium characteristics. SEM and TEM analyses evidenced 5-2 nm which are agglomerated, cool to form porous asymmetrical networks. Additionally, the FTIR spectrum showed maximum peak at 1194 cm-1 and 1394 cm-1, confirming the presence of aromatic CH bending and aromatic CC bending in the SNM. SNM exhibited prolific antibacterial activity against Gram negative pathogens, K. pneumoniae (28.33 mm) and E. coli (21.66 mm) respectively. The MIC values of SNM were significant with respect to E. faecalis (125 µg/ml), S. aureus (250 µg/ml), P. aeruginosa (125 µg/ml), K. pneumoniae (500 µg/ml) and E. coli (250 µg/ml) respectively. In addition, the antioxidant potential of the SNM was another value added importance. Especially 50 µg/ml of the nanoparticles showed 33% antioxidant potential; similarly in nitric oxide radical inhibition assay the concentration of 50 µg/ml nanoparticles showed 33% of inhibition potential. Overall, the eco-friendly synthesis of SNM from the marine Streptomyces strain Al-Dhabi-91 was an ideal active source for the treatment of infectious disease and health associated disorders.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Sedimentos Geológicos/microbiologia , Nanopartículas Metálicas/química , Prata/química , Streptomyces/química , Anti-Infecciosos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Química Verde , Nanopartículas Metálicas/toxicidade , Testes de Sensibilidade Microbiana , Filogenia , Arábia Saudita , Streptomyces/classificação , Streptomyces/isolamento & purificação
18.
Food Chem ; 295: 16-25, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174745

RESUMO

The instability of Laurel essential oil (LEO) and easy leakage of silver nanoparticle (AgNP) restricts their application in food field. To control their release, liposomes were used to encapsulate LEO and AgNPs (Lip-LEO-AgNPs), and mixed with chitosan to coat polyethylene (PE) films (PC-Lip/LEO/AgNPs) to package pork. The results show that only about 29.30% of LEO and 11.79% of AgNPs were released from the liposome after 7 days at 25 °C. Nevertheless, Lip-LEO-AgNPs showed good antioxidant properties. Moreover, PC-Lip/LEO/AgNPs films had good antimicrobial activity. Evaluation tests on pork indicate that PC-Lip/LEO/AgNPs films could keep the quality of pork at 4 °C for 15 days while pure PE film only kept it for 9 days, and that the coating films had no cytotoxicity. PC-Lip/LEO/AgNPs films exhibited significant combined action in functional packaging to extend storage period, and provided a new idea for the application of LEO and AgNPs in food.


Assuntos
Conservação de Alimentos/métodos , Lipossomos/química , Óleos Voláteis/química , Carne Vermelha , Sesquiterpenos/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Quitosana/química , Qualidade dos Alimentos , Armazenamento de Alimentos/métodos , Humanos , Lipossomos/farmacologia , Nanopartículas Metálicas/química , Óleos Voláteis/farmacologia , Tamanho da Partícula , Sesquiterpenos/farmacologia , Prata/química , Suínos , Temperatura Ambiente
19.
Anal Chim Acta ; 1073: 62-71, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31146837

RESUMO

In this study, silver nanostructures decorated magnetic nanoparticles for surface-enhanced Raman scattering (SERS) measurements were prepared via heat induced catalytic activity of ZnO nanostructures. The ZnO/Fe3O4 composite was first prepared by dispersing pre-formed magnetic nanoparticles into alkaline zinc nitrate solutions. After annealing of the precipitates, the formed ZnO/Fe3O4 composites were successfully decorated with silver nanostructures by dispersing the composites into silver nitrate/ethylene glycol solution at 95 °C in water bath. To find the optimal condition when preparing Ag/ZnO/Fe3O4 composites for SERS measurements, factors such as reaction time and concentration of silver nitrate were studied. Results indicated that the formation of silver nanoparticles (AgNPs) on ZnO/Fe3O4 was significantly improved with the assistance of ZnO. The concentration of silver nitrate and reaction time affected the morphologies and sizes of the formed composites and optimal condition in preparation of the composites for SERS measurement was found using 100 mM of silver nitrate with a reaction time of 20 min. Under optimized conditions, the obtained SERS intensities were highly reproducible. The substrates were applied for quantitative analysis of uric acid in aqueous solution and a linear response for concentrations up to 10 µM was obtained. Successful application of these prepared composites to determine uric acid in urine sample without any pretreatment of the urine sample was done.


Assuntos
Óxido Ferroso-Férrico/química , Nanopartículas de Magnetita/química , Nanopartículas Metálicas/química , Prata/química , Ácido Úrico/análise , Óxido de Zinco/química , Tamanho da Partícula , Análise Espectral Raman , Propriedades de Superfície
20.
Anal Chim Acta ; 1072: 46-53, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31146864

RESUMO

In clinical practice, the excess concentration of bilirubin can trigger diseases such as neonatal jaundice, hepatic failure, septicemia, and so on. The concentration of bilirubin is one of important clinical indexes to evaluate patients with hepatic function disease in clinical practice. Therefore, it is very necessary to develop a rapid detection technique detecting the bilirubin in body fluids. Here, a new electrochemical sensor based on Au nanoparticles/tetrathiafulvalene-carboxylate functionalized reduced grapheneoxide 0D-2D heterojunction(AuNPs/TTF-COOH/RGO) was fabricated for the discrimination of bilirubin in real human blood. The TTF-COOH could effectively repair electron conductivity of RGO nanosheets, decrease interface resistance, and also enhance the dispersity of TTF-COOH/RGO nanosheets in water. What's more, the S atoms of TTF-COOH can bonding the gold nano-particles (AuNPs) to fabricate a 0D-2D heterojunction with excellent biocompatibility and enhanced specific surface area. After bilirubin oxidases were self-assembled on the surface of AuNPs, a specific recognition interface was formed as a sensor for the detection of bilirubin. The heterojunction showed enhanced interface electron transfer rate, excellent biocompatibility, and also prominent electrocatalytic activity for the high efficiency catalysis of bilirubin. The sensor shows a linear response for bilirubin from 2.66 to 83  µmol L-1 and a low detection limit of 0.74 µmol L-1 at 3σ. This work provides one novel approach to detection of bilirubin by functional RGO nanosheets, and broadens the application area of RGO nanosheets in selective catalysis and detection of biomolecule in biological specimens, such as blood, urine.


Assuntos
Bilirrubina/sangue , Ácidos Carboxílicos/química , Técnicas Eletroquímicas , Ouro/química , Grafite/química , Compostos Heterocíclicos/química , Nanopartículas Metálicas/química , Eletrodos , Humanos , Prata/química
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