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1.
Small ; : e2401558, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38829043

RESUMO

By primarily adjusting the reagent amounts, particularly the volume of AgNO3 solution introduced, Ag2O cubes with decreasing sizes from 440 to 79 nm, octahedra from 714 to 106 nm, and rhombic dodecahedra from 644 to 168 nm are synthesized. 733 nm cuboctahedra are also prepared for structural analysis. With in-house X-ray diffraction (XRD) peak calibration, shape-related peak shifts are recognizable. Synchrotron XRD measurements at 100 K reveal the presence of bulk and surface layer lattices. Bulk cell constants also deviate slightly. They show a negative thermal expansion behavior with shrinking cell constants at higher temperatures. The Ag2O crystals exhibit size- and facet-dependent optical properties. Bandgaps red-shift continuously with increasing particle sizes. Optical facet effect is also observable. Moreover, synchrotron XRD peaks of a mixture of Cu2O rhombicuboctahedra and edge- and corner-truncated cubes exposing all three crystal faces can be deconvoluted into three components with the bulk and the [111] microstrain phase as the major component. Interestingly, while the unheated Cu2O sample shows clear diffraction peak asymmetry, annealing the sample to 450 K yields nearly symmetric peaks even when returning the sample to room temperature, meaning even moderately high temperatures can permanently change the crystal lattice.

2.
Chemistry ; 30(44): e202401637, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-38837442

RESUMO

We propose silver oxide as a cost-effective and sustainable alternative to noble metals for the catalytic reduction of nitroaromatics. In the present investigation, we adopt a facile and green synthetic route for the synthesis of silver oxide nanostructures. The prepared nanostructures were found to crystallize in the cuprite phase and exhibit absorbance across the entire visible range of the electromagnetic spectrum. The catalytic potential of the silver oxide was evaluated by following the kinetics of nitrophenol reduction under ambient conditions and is observed to follow pseudo-first order kinetics with the apparent rate constant k a p p = 4 . 24 × 10 - 3 ${{k}_{app}=4.24\ \times {10}^{-3}}$ s-1 at minimum concentration of the catalyst. We attribute the observed catalytic activity to the freshly generated catalytic surface featuring a partially reduced form of silver oxide during reaction. The findings highlight the efficacy of silver oxide in mitigating the environmental pollution originating from the recalcitrant nitroarenes.

3.
Microb Cell Fact ; 23(1): 220, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39107838

RESUMO

BACKGROUND: Biotechnology provides a cost-effective way to produce nanomaterials such as silver oxide nanoparticles (Ag2ONPs), which have emerged as versatile entities with diverse applications. This study investigated the ability of endophytic bacteria to biosynthesize Ag2ONPs. RESULTS: A novel endophytic bacterial strain, Neobacillus niacini AUMC-B524, was isolated from Lycium shawii Roem. & Schult leaves and used to synthesize Ag2ONPS extracellularly. Plackett-Burman design and response surface approach was carried out to optimize the biosynthesis of Ag2ONPs (Bio-Ag2ONPs). Comprehensive characterization techniques, including UV-vis spectral analysis, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, dynamic light scattering analysis, Raman microscopy, and energy dispersive X-ray analysis, confirmed the precise composition of the Ag2ONPS. Bio-Ag2ONPs were effective against multidrug-resistant wound pathogens, with minimum inhibitory concentrations (1-25 µg mL-1). Notably, Bio-Ag2ONPs demonstrated no cytotoxic effects on human skin fibroblasts (HSF) in vitro, while effectively suppressing the proliferation of human epidermoid skin carcinoma (A-431) cells, inducing apoptosis and modulating the key apoptotic genes including Bcl-2 associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), Caspase-3 (Cas-3), and guardian of the genome (P53). CONCLUSIONS: These findings highlight the therapeutic potential of Bio-Ag2ONPs synthesized by endophytic N. niacini AUMC-B524, underscoring their antibacterial efficacy, anticancer activity, and biocompatibility, paving the way for novel therapeutic strategies.


Assuntos
Antibacterianos , Nanopartículas Metálicas , Compostos de Prata , Humanos , Nanopartículas Metálicas/química , Compostos de Prata/farmacologia , Compostos de Prata/química , Antibacterianos/farmacologia , Antibacterianos/biossíntese , Testes de Sensibilidade Microbiana , Bacillaceae/metabolismo , Óxidos/farmacologia , Óxidos/química , Fibroblastos/efeitos dos fármacos , Apoptose/efeitos dos fármacos
4.
Biometals ; 37(4): 971-982, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38409305

RESUMO

The 'sacred leaf' or "Hoja Santa" (Piper auritum Kunth) has a great value for Mexican culture and has gained popularity worldwide for its excellent properties from culinary to remedies. To contribute to its heritage, in this project we proposed the green synthesis of silver oxide nanoparticles (Ag2O NPs) using an extract of "Hoja Santa" (Piper auritum) as a reducing and stabilizing agent. The synthesized Ag2O NPs were characterized by UV-Visible spectroscopy (plasmon located at 405 nm), X-ray diffraction (XRD) (particle size diameter of 10 nm), scanning electron microscopy (SEM) (particle size diameter of 13.62 ± 4.61 nm), and Fourier-transform infrared spectroscopy (FTIR) (functional groups from "Hoja Santa" attached to nanoparticles). Antioxidant capacity was evaluated using DPPH, ABTS and FRAP methods. Furthermore, the antimicrobial activity of NPs against a panel of clinically relevant bacterial strains, including both Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Salmonella Enteritidis and Escherichia coli O157:H7), was over 90% at concentrations of 200 µg/mL. Additionally, we assessed the antibiofilm activity of the NPs against Pseudomonas aeruginosa (reaching 98% of biofilm destruction at 800 µg/mL), as biofilm formation plays a crucial role in bacterial resistance and chronic infections. Moreover, we investigated the impact of Ag2O NPs on immune cell viability, respiratory burst, and phagocytic activity to understand their effects on the immune system.


Assuntos
Antibacterianos , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Piper , Extratos Vegetais , Compostos de Prata , Staphylococcus aureus , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Compostos de Prata/química , Compostos de Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Piper/química , Nanopartículas Metálicas/química , Óxidos/química , Óxidos/farmacologia , Antioxidantes/farmacologia , Antioxidantes/química , Antioxidantes/síntese química , Animais , Camundongos , Salmonella enteritidis/efeitos dos fármacos , Tamanho da Partícula , Células RAW 264.7 , Escherichia coli O157/efeitos dos fármacos , Folhas de Planta/química
5.
Environ Sci Technol ; 57(41): 15715-15724, 2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37807513

RESUMO

Bisphenol B (BPB, 2,2-bis(4-hydroxyphenyl) butane), as a substitute for bisphenol A, has been widely detected in the environment and become a potential threat to environmental health. This work found that silver oxide nanoparticles (Ag2O) could greatly promote the removal of BPB by ferrate (Fe(VI)). With the presence of 463 mg/L Ag2O, the amount of Fe(VI) required for the complete removal of 10 µM BPB will be reduced by 70%. Meanwhile, the recyclability and stability of Ag2O have been verified by recycling experiments. The characterization results and in situ electrochemical analyses showed that Ag(II) was produced from Ag(I) in the Fe(VI)-Ag2O system, which has a higher electrode potential to oxidize BPB to enhance its removal. A total of 13 intermediates were identified by high-resolution mass spectrometry, and three main reaction pathways were proposed, including oxygen transfer, bond breaking, and polymerization. Based on the toxicity assessment through the ECOSAR program, it is considered that the presence of Ag2O reduced the toxicity of BPB oxidation intermediates to aquatic organisms. These results would deepen our understanding of the interaction between Fe(VI) and Ag2O, which may provide an efficient and environmentally friendly method for water and wastewater treatment.


Assuntos
Nanopartículas , Poluentes Químicos da Água , Purificação da Água , Ferro/química , Oxirredução , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos
6.
Int J Mol Sci ; 24(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36614309

RESUMO

Foodborne infections are an important global health problem due to their high prevalence and potential for severe complications. Bacterial contamination of meat during processing at the enterprise can be a source of foodborne infections. Polymeric coatings with antibacterial properties can be applied to prevent bacterial contamination. A composite coating based on fluoroplast and Ag2O NPs can serve as such a coating. In present study, we, for the first time, created a composite coating based on fluoroplast and Ag2O NPs. Using laser ablation in water, we obtained spherical Ag2O NPs with an average size of 45 nm and a ζ-potential of -32 mV. The resulting Ag2O NPs at concentrations of 0.001-0.1% were transferred into acetone and mixed with a fluoroplast-based varnish. The developed coating made it possible to completely eliminate damage to a Teflon cutting board. The fluoroplast/Ag2O NP coating was free of defects and inhomogeneities at the nano level. The fluoroplast/Ag2O NP composite increased the production of ROS (H2O2, OH radical), 8-oxogualnine in DNA in vitro, and long-lived active forms of proteins. The effect depended on the mass fraction of the added Ag2O NPs. The 0.01-0.1% fluoroplast/NP Ag2O coating exhibited excellent bacteriostatic and bactericidal properties against both Gram-positive and Gram-negative bacteria but did not affect the viability of eukaryotic cells. The developed PTFE/NP Ag2O 0.01-0.1% coating can be used to protect cutting boards from bacterial contamination in the meat processing industry.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Antibacterianos/farmacologia , Politetrafluoretileno , Peróxido de Hidrogênio , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Bactérias , Carne
7.
Nanotechnology ; 33(40)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35767930

RESUMO

Alternating current electroluminescent (AC-EL) device can be considered as a potential candidate for next generation of multifunctional light-emitting sources. In this work, we present a new design of AC-EL device with inclusion of a silver oxide humidity-sensing layer instead of an insulating buffer layer for humidity detection. The ZnS:Cu, Cl and ZnS:Ag+(Zn,Cd)S:Ag phosphors were used as an emissive layer prepared by screen printing method. The silver oxide (AgO/Ag2O) nanoparticles synthesized via a green method were employed as a humidity sensing layer. The developed AC-EL devices exhibited high response, good productivity, high stability, high repeatability and linear relationship with humidity in range of 10%-90% RH as well as no significant effects with several VOCs/gases such as NH3, CO2, acetone, methanol, toluene and propan at room temperature. The effects of parameters such as excitation frequency, applied voltage, and waveforms on the luminance intensity are discussed. The development of the present AC-EL device offers a simplified architecture to enable sensing functions of the AC-EL device via monitoring of light emission changing.

8.
J Environ Manage ; 311: 114884, 2022 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-35287075

RESUMO

In this study, nano-sized silver oxides were loaded on activated carbon (nAg2O/AC) through a facile impregnation-calcination method for enhanced bacterial inactivation from drinking water, in which Escherichia coli (E. coli) was used as target bacteria. XRD and SEM characterization confirmed that nano-sized Ag2O particles (50-200 nm) were successfully prepared and uniformly distributed on the surfaces and pores of AC. Due to the structural reducing groups of AC, surface-bound Ag(I) was partially converted to Ag in the nAg2O matrix and the resulted Ag could sterilize E. coli directly. More importantly, surface-bound Ag could catalyze O2 and H2O to generate reactive oxygen species (ROS) for oxidation sterilization, thus significantly enhanced the inactivation efficiency from 0.8 log10 CFU/mL (nAg2O control) and 0.2 log10 CFU/mL (AC control) to 6.0 log10 CFU/mL in the nAg2O/AC system. The inactivation process was highly pH-dependent, and neutral pH was favorable for sterilization. A sterilization efficiency of 5.2 log10 CFU/mL could still be achieved after 5 running cycles, indicating stable sterilization performance of nAg2O/AC. In addition, the nAg2O/AC also exhibited excellent renewability since a sterilization efficiency of 5.8 log10 CFU/mL was obtained after nAg2O being stripped and reloaded on the AC. These results demonstrated that nAg2O-modified AC is an efficient material for sterilization in water treatment.

9.
Int J Environ Health Res ; 32(3): 616-627, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32627584

RESUMO

As therapeutic antiviral agents, biological nanoparticles can fight the drug-resistant types of viruses helping the antiviral drug development. In this study, two blue-green algal strains; Oscillatoria sp. and Spirulina platensis were used, mediated by green Ag2O|AgO-NPs and Au-NPs, respectively. For NPs characterization, the UV/Vis spectroscopy were used where their formation and crystallinity were proven with λmax values for silver and gold NPs of 432 and 552 nm, respectively. The transmission electron microscope (TEM) X-ray diffraction showed a spherical-shaped Ag2O|AgO-NPs (size; 14.42 to 48.97) while Au-NPs appeared with octahedral, pentagonal and triangular structures (size; 15.60-77.13 nm). The reducing, capping, and stabilization activities of algal polysaccharides and proteins were indicated via FTIR spectroscopy. Both Ag2O|AgO-NPs and Au-NPs were investigated against Herpes Simplex virus (HSV-1) that has been indicated by its reduction activity of cytopathic effect (CPE). Cytotoxicity was evaluated on Vero cells and measured by MTT assay. Results showed a 90% reduction in CPE of HSV-1 applying Ag2O|AgO-NPs, and Au-NPs at 31.25 µL., with a high reduction rate (49.23%) with Ag2O|AgO-NPs than that of Au-NPs (42.75%). Current results proved the efficiency of green nanotechnology application with both Ag2O|AgO-NPs, and Au-NPs as reducing and inhibitory agents for the HSV-1 replication.


Assuntos
Herpesvirus Humano 1 , Nanopartículas Metálicas , Animais , Antivirais/farmacologia , Chlorocebus aethiops , Técnicas de Cultura , Ouro , Prata , Células Vero
10.
Mol Biol Rep ; 48(12): 7933-7946, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34655404

RESUMO

BACKGROUND: There is an emergency need for the natural therapeutic agents to treat arious life threatening diseases such as cardio- vascular disease, Rheumatoid arthritis and cancer. Among these diseases, cancer is found to be the second life threatening disease; in this view the present study focused to synthesize the silver oxide nanoparticles (AgONPs) from endophytic fungus. METHODS: The endophytic fungus was isolated from a medicinal tree Aegle marmelos (Vilva tree) and the potential strain was screened through antagonistic activity. The endophytic fungus was identified through microscopic (Lactophenol cotton blue staining and spore morphology in culture media) and Internal Transcribed Spacer (ITS) 1, ITS 4 and 18S rRNA amplification. The endophyte was cultured for the synthesis of AgONPs and the synthesized NPs were characterized through UV- Vis, FT- IR, EDX, XRD and SEM. The synthesized AgONPs were determined for antimicrobial, antioxidant and anti- angiogenic activity. RESULTS: About 35 pigmented endophytic fungi were isolated, screened for antagonistic activity against 12 pathogens and antioxidant activity through DPPH radical scavenging assay; among the isolates, FC36AY1 explored the highest activity and the strain FC36AY1 was identified as Aspergillus terreus. The AgONPs were synthesized from the strain FC36AY1 and characterized for its confirmation, functional groups, nanostructures with unit cell dimensions, size and shape, presence of elements through UV-Vis spectrophotometry, FT-IR, XRD, SEM with EDX analysis. The myco-generated AgONPs manifested their antimicrobial and antioxidant properties with maximum activity at minimum concentration. Moreover, the inhibition of angiogenesis by the AgONPs in Hen's Egg Test on the Chorio-Allantoic Membrane analysis were tested on the eggs of Chittagong breed evinced at significant bioactivity least concentration at 0.1 µg/mL. CONCLUSIONS: Thus, the results of this study revealed that the fungal mediated AgONPs can be exploited as potential in biomedical applications.


Assuntos
Aspergillus/metabolismo , Nanopartículas Metálicas/química , Óxidos/química , Compostos de Prata/química , Inibidores da Angiogênese/farmacologia , Animais , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Aspergillus/enzimologia , Embrião de Galinha/efeitos dos fármacos , Endófitos/metabolismo , Testes de Sensibilidade Microbiana/métodos , Óxidos/farmacologia , Compostos de Prata/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
11.
Sensors (Basel) ; 21(6)2021 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-33804688

RESUMO

Wearable electronics are playing an important role in the health care industry. Wearable sensors are either directly attached to the body surface or embedded into worn garments. Textile-based batteries can help towards development of body conformal wearable sensors. In this letter, we demonstrate a 2D planar textile-based primary Ag2O-Zn battery fabricated using the stencil printing method. A synthetic polyester woven fabric is used as the textile substrate and polyethylene oxide material is used as the separator. The demonstrated battery achieves an areal capacity of 0.6 mAh/cm2 with an active electrode area of 0.5 cm × 1 cm.


Assuntos
Dispositivos Eletrônicos Vestíveis , Fontes de Energia Elétrica , Prata , Têxteis , Zinco
12.
Ceram Int ; 47(3): 2917-2948, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32994658

RESUMO

Nanomedicine has seen a significant rise in the development of new research tools and clinically functional devices. In this regard, significant advances and new commercial applications are expected in the pharmaceutical and orthopedic industries. For advanced orthopedic implant technologies, appropriate nanoscale surface modifications are highly effective strategies and are widely studied in the literature for improving implant performance. It is well-established that implants with nanotubular surfaces show a drastic improvement in new bone creation and gene expression compared to implants without nanotopography. Nevertheless, the scientific and clinical understanding of mixed oxide nanotubes (MONs) and their potential applications, especially in biomedical applications are still in the early stages of development. This review aims to establish a credible platform for the current and future roles of MONs in nanomedicine, particularly in advanced orthopedic implants. We first introduce the concept of MONs and then discuss the preparation strategies. This is followed by a review of the recent advancement of MONs in biomedical applications, including mineralization abilities, biocompatibility, antibacterial activity, cell culture, and animal testing, as well as clinical possibilities. To conclude, we propose that the combination of nanotubular surface modification with incorporating sensor allows clinicians to precisely record patient data as a critical contributor to evidence-based medicine.

13.
Chemistry ; 26(36): 8053-8063, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32145116

RESUMO

Following our discovery that silver(I) oxide-promoted glycosylation with glycosyl bromides can be greatly accelerated in the presence of catalytic TMSOTf or TfOH, we report herein a new discovery that glycosyl chlorides are even more effective glycosyl donors under these reaction conditions. The developed reaction conditions work well with a variety of glycosyl chlorides. Both benzoylated and benzylated chlorides have been successfully glycosidated, and these reaction conditions proved to be effective in coupling substrates containing nitrogen and sulfur atoms. Another convenient feature of this glycosylation is that the progress of the reaction can be monitored visually; its completion can be judged by the disappearance of the characteristic dark color of Ag2 O.

14.
Mikrochim Acta ; 187(11): 591, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33025245

RESUMO

An electrochemical method has been developed to determine iodide in urine using an electrode modified with silver oxide microparticles-poly acrylic acid/poly vinyl alcohol (Ag2OMPs-PAA/PVA). Silver oxide particles were formed by electrochemical oxidation via cyclic voltammetry. The modified electrode exhibited an excellent response to iodide detection by cathodic stripping voltammetry. The fabrication and operation conditions were optimized in terms of PVA concentration, K2HPO4 concentration, amount of AgMPs-PAA/PVA, number of cycles for oxide formation, electrolyte, applied potential (vs. Ag/AgCl), and time. Under the optimum conditions, iodide determination produced a linear range from 1 to 40 µM. The limit of detection was 0.3 µM. Precision was found to be within 7.4% RSD. The developed method was applied to the determination of iodide in urine samples of pregnant women with satisfying recoveries (86 ± 1 to 108 ± 1%). Graphical abstract.


Assuntos
Iodetos/urina , Gravidez/urina , Resinas Acrílicas/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Feminino , Humanos , Iodetos/química , Iodo/deficiência , Limite de Detecção , Óxidos/química , Álcool de Polivinil/química , Complicações na Gravidez/diagnóstico por imagem , Complicações na Gravidez/urina , Compostos de Prata/química
15.
Molecules ; 25(10)2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32414219

RESUMO

The present study aimed to explore the eco-friendly synthesis of prism-like silver oxide nanoparticles (Ag2ONPs) from nappa cabbage extract and its p-nitrophenol sensing activity. The prepared Ag2ONPs were characterized by X-ray diffraction (XRD), field-emission scanning spectroscopy (FESEM), energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and ultraviolet (UV)-visible light spectral analysis (UV-Vis). p-Nitrophenol sensing properties of the prepared nanoparticles were also determined using a simple I-V method. The results showed that the as-prepared Ag2ONPs have a face-centered cubic (fcc) crystalline nature and a prism-like morphology with particle size in the range 21.61-92.26 nm. The result also showed a high intensity of the (111) facet, making the Ag2ONP-carbon black/nickel foam electrode (Ag2ONP-C/NFE) exhibit a high-performance response to p-nitrophenol spanning a wide range of concentrations from 1.0 mM to 0.1 pM and a response time of around 5 s, indicating a high potential for water treatment applications.


Assuntos
Brassica napus/química , Nanopartículas/química , Nitrobenzenos/análise , Óxidos/química , Extratos Vegetais/química , Compostos de Prata/química , Nanopartículas/ultraestrutura , Tamanho da Partícula
16.
Inflammopharmacology ; 26(4): 1025-1035, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29204780

RESUMO

Silver and silver oxides are gaining interest in medical applications for their prominent antibacterial and antimicrobial potentials. Recent studies suggest that nanosilver oxide has remarkable anti-inflammatory effects and enhances wound healing. Nevertheless, its effect on gastric ulcer has not yet been illustrated. Thus the current study aimed to explore the prospect protective effect of nanosilver oxide against indomethacin-induced gastric ulcer. A new approach has been followed to synthesize nanosilver oxide. X-ray diffraction, UV-Vis spectroscopy and transition electron microscope techniques have been successfully used to characterize the synthesized nanoparticles. Treatment of ulcerated rats with different doses of nanosilver oxide especially (175 and 350 ppm/p.o.) alleviated adverse effects of indomethacin-induced gastric injury as demonstrated by decreasing ulcer index and elevating % of ulcer inhibition. These positive effects excelled those exerted by the reference antiulcer drug omeprazole. Nanosilver oxide suppressed gastric inflammation by reducing myeloperoxidase, tumor necrosis alpha, interleukin 1beta and interferon gamma. Moreover, nanosilver oxide halted gastric oxidative stress via inhibiting lipid  peroxidation and enhancing glutathione and paraoxonase-1. Regarding gastric apoptosis, nanosilver oxide down regulated the expression of caspase 9, tumor protein 53, and nuclear factor kappa B and allograft inflammatory factor-1 genes. These findings emphasize the antiulcerogenic potential of nanosilver oxide against indomethacin-induced gastric ulcers which are multi-factorial including anti-inflammatory, antioxidant and antiapoptotic effects.


Assuntos
Antiulcerosos/farmacologia , Nanopartículas Metálicas , Óxidos/farmacologia , Compostos de Prata/farmacologia , Úlcera Gástrica/prevenção & controle , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios não Esteroides/toxicidade , Antiulcerosos/administração & dosagem , Antioxidantes/administração & dosagem , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Relação Dose-Resposta a Droga , Indometacina/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Microscopia Eletrônica de Transmissão , Estresse Oxidativo/efeitos dos fármacos , Óxidos/administração & dosagem , Ratos , Ratos Wistar , Compostos de Prata/administração & dosagem , Úlcera Gástrica/induzido quimicamente , Difração de Raios X
17.
Chemotherapy ; 62(5): 279-289, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28490010

RESUMO

BACKGROUND: Development of novel strategies to kill cancer by sparing normal cells is of utmost importance. Apart from their known antimicrobial activity, only limited information has been recorded regarding the antitumor potential of biocompatible silver oxide nanoparticles (AgONPs). There is a need to evaluate the anticancer potential of biocompatible AgONPs in vitro. METHODS: A new approach of utilizing the leaf extract of Excoecaria agallocha was used to synthesize AgONPs. This was then characterized by ultraviolet-visible spectrophotometry, nanoparticle-tracking analysis, and ζ-potential analysis. Cytotoxicity and apoptotic potential were evaluated with an MTT assay and an annexin V-binding assay against the murine melanoma (B16F10), murine colon cancer (CT26), murine lung adenocarcinoma (3LL), and murine Ehrlich ascites carcinoma (EAC) cell lines. Cellular localization of AgONPs was evaluated on fluorescence microscopy. RESULTS: UV peaks at 270 and 330 nm indicated the formation of nanoparticles (NPs) and the NP-tracking analyzer revealed them to have a size of 228 nm. AgONPs exerted initial cytotoxicity, specifically against all the experimental malignant cells by sparing the normal cell lines. Moreover, AgONPs exert apoptosis equally on all the malignant cells in vitro and ex vivo. This cytotoxicity possibly occurs via the nuclear translocation of AgONPs as analyzed in B16F10 cells. CONCLUSIONS: AgONPs utilizing natural sources would be a new medicinal approach against a broad spectrum of malignancy.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Nanopartículas Metálicas/química , Óxidos/química , Extratos Vegetais/farmacologia , Compostos de Prata/química , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Euphorbiaceae/química , Euphorbiaceae/metabolismo , Química Verde , Humanos , Camundongos , Microscopia Confocal , Tamanho da Partícula , Extratos Vegetais/química , Folhas de Planta/química , Folhas de Planta/metabolismo
18.
Molecules ; 22(9)2017 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-28880225

RESUMO

This paper reports the synthesis and characterization of silver oxide films for use as bactericidal coatings. Synthesis parameters, dissolution/elution rate, and bactericidal efficacy are reported. Synthesis conditions were developed to create AgO, Ag2O, or mixtures of AgO and Ag2O on surfaces by reactive magnetron sputtering. The coatings demonstrate strong adhesion to many substrate materials and impede the growth of all bacterial strains tested. The coatings are effective in killing Escherichia coli and Staphylococcus aureus, demonstrating a clear zone-of-inhibition against bacteria growing on solid media and the ability to rapidly inhibit bacterial growth in planktonic culture. Additionally, the coatings exhibit very high elution of silver ions under conditions that mimic dynamic fluid flow ranging between 0.003 and 0.07 ppm/min depending on the media conditions. The elution of silver ions from the AgO/Ag2O surfaces was directly impacted by the complexity of the elution media, with a reduction in elution rate when examined in complex cell culture media. Both E. coli and S. aureus were shown to bind ~1 ppm Ag⁺/mL culture. The elution of Ag⁺ resulted in no increases in mammalian cell apoptosis after 24 h exposure compared to control, but apoptotic cells increased to ~35% by 48 and 72 h of exposure. Taken together, the AgO/Ag2O coatings described are effective in eliciting antibacterial activity and have potential for application on a wide variety of surfaces and devices.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Óxidos/química , Óxidos/farmacologia , Compostos de Prata/química , Compostos de Prata/farmacologia , Prata/química , Células 3T3 , Animais , Sobrevivência Celular , Escherichia coli/efeitos dos fármacos , Humanos , Íons/química , Camundongos , Testes de Sensibilidade Microbiana/métodos , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
19.
Chemistry ; 22(34): 12160-5, 2016 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-27430192

RESUMO

In this work, single-crystal and single-domain PbTiO3 nanoplates are employed as substrates to prepare Ag2 O/PbTiO3 composite materials through a photodeposition method. It is revealed that silver oxide nanocrystals with an average size of 63 nm are selectively deposited on the positive polar surface of the ferroelectric substrate. The possible mechanism leading to the formation of silver oxide is that silver ions are first reduced to silver and then oxidized by oxygen generation. The composite shows an efficient photodegradation performance towards rhodamine B (RhB) and methyl orange (MO) under visible-light irradiation. Such highly efficient photoactivity can be attributed to the ferroelectric polarization effect of the substrate, which promotes the separation of photogenerated electrons and holes at the interface.

20.
Bot Stud ; 65(1): 17, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38985236

RESUMO

BACKGROUND: Silver nanoparticles are widely used in various fields such as industry, medicine, biotechnology, and agriculture. However, the inevitable release of these nanoparticles into the environment poses potential risks to ecosystems and may affect plant productivity. Coronatine is one of the newly identified compounds known for its beneficial influence on enhancing plant resilience against various stress factors. To evaluate the effectiveness of coronatine pretreatment in mitigating the stress induced by silver nanoparticles on cress plants, the present study was carried out. RESULTS: Our findings indicated a decrease in multiple growth parameters, proline content, chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in cress plants exposed to silver nanoparticle treatment. This decline could be attributed to the oxidative stress induced by the presence of silver nanoparticles in the plants. Conversely, when coronatine treatment was applied, it effectively mitigated the reduction in growth parameters and pigments induced by the silver nanoparticles. Furthermore, we observed an increase in silver content in both the roots and shoot portions, along with elevated levels of malondialdehyde (MDA) content, hydrogen peroxide (H2O2), anthocyanins, glutathione (GSH), and antioxidant enzyme activities in plants exposed to silver nanoparticles. Concurrently, there was a decrease in total phenolic compounds, ascorbate, anthocyanins, and proline content. Pre-treatment of cress seeds with coronatine resulted in increased levels of GSH, total phenolic compounds, and proline content while reducing the silver content in both the root and shoot parts of the plant. CONCLUSIONS: Coronatine pre-treatment appeared to enhance both enzymatic and non-enzymatic antioxidant activities, thereby alleviating oxidative stress and improving the response to stress induced by silver nanoparticles.

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