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1.
Int J Mol Sci ; 22(5)2021 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-33802614

RESUMEN

In this study, dense gold-assembled SiO2 nanostructure (SiO2@Au) was successfully developed using the Au seed-mediated growth. First, SiO2 (150 nm) was prepared, modified by amino groups, and incubated by gold nanoparticles (ca. 3 nm Au metal nanoparticles (NPs)) to immobilize Au NPs to SiO2 surface. Then, Au NPs were grown on the prepared SiO2@Au seed by reducing chloroauric acid (HAuCl4) by ascorbic acid (AA) in the presence of polyvinylpyrrolidone (PVP). The presence of bigger (ca. 20 nm) Au NPs on the SiO2 surface was confirmed by transmittance electronic microscopy (TEM) images, color changes to dark blue, and UV-vis spectra broadening in the range of 450 to 750 nm. The SiO2@Au nanostructure showed several advantages compared to the hydrofluoric acid (HF)-treated SiO2@Au, such as easy separation, surface modification stability by 11-mercaptopundecanoic acid (R-COOH), 11-mercapto-1-undecanol (R-OH), and 1-undecanethiol (R-CH3), and a better peroxidase-like catalysis activity for 5,5'-Tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) reaction. The catalytic activity of SiO2@Au was two times better than that of HF-treated SiO2@Au. When SiO2@Au nanostructure was used as a surface enhanced Raman scattering (SERS) substrate, the signal of 4-aminophenol (4-ATP) on the surface of SiO2@Au was also stronger than that of HF-treated SiO2@Au. This study provides a potential method for nanoparticle preparation which can be replaced for Au NPs in further research and development.


Asunto(s)
Oro/química , Nanopartículas del Metal/química , Nanoestructuras/química , Dióxido de Silicio/química , Aminofenoles/química , Bencidinas/química , Técnicas Biosensibles/métodos , Catálisis , Ácido Fluorhídrico/química , Peróxido de Hidrógeno/química , Límite de Detección , Povidona/química , Plata/química , Compuestos de Sulfhidrilo/química
2.
Analyst ; 146(7): 2131-2137, 2021 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-33861260

RESUMEN

As inflammation plays a role in the pathogenesis of acute coronary syndromes, C-reactive protein (CRP) can be used as a biomarker. To detect CRP precisely, the authors prepared a CRP electrochemical biosensor consisting of an eight Ag ion-intercalated multifunctional DNA four-way junction (MF-DNA-4WJ) and a porous rhodium nanoparticle (pRhNP) heterolayer on a micro-gap electrode. To increase conductivity, we used eight Ag+ ion-inserted DNA four-way junctions through a C-C mismatch. Each DNA 4WJ was designed to have the CRP aptamer sequence, an anchoring region (thiol group), and two of four C-C mismatch regions at the end of the fragments. After an annealing step, the MF-DNA-4WJ assembly configuration and selective binding of CRP were confirmed through native TBM-PAGE (Tris-borate-magnesium chloride-polyacrylamide gel electrophoresis). The Au micro-gap electrode was fabricated to load 5 µl of the sample, and this was performed during eight experiments on one chip to establish the accuracy of the data. Then, pRhNPs were immobilized on a Au micro-gap electrode using cysteamine. To confirm the electrochemical properties, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were conducted. The durability of pRhNPs was confirmed through CV. To test the sensing performance of the prepared CRP biosensor, the limit of detection (LOD) and selectivity tests were conducted using EIS. The results indicated that charge transfer resistance (Rct) can be used efficiently to probe these interactions within the variable CRP concentration range, from 1 pM to 100 nM (0.23 ng L-1-23 µg L-1). The LOD of this sensor was 0.349 pM (0.08 ng L-1) (at S/N = 3). As a result of diluting the CRP to the same concentration range in a 20% human serum sample, the LOD was 3.55 fM (0.814 pg L-1) (at S/N = 3).


Asunto(s)
Técnicas Biosensibles/métodos , Proteína C-Reactiva/análisis , ADN/química , Oro/química , Rodio/química , Plata/química , ADN/genética , Técnicas Electroquímicas , Electrodos , Humanos , Nanopartículas del Metal , Sensibilidad y Especificidad
3.
Sci Rep ; 11(1): 8692, 2021 04 22.
Artículo en Inglés | MEDLINE | ID: mdl-33888738

RESUMEN

A metal nanoparticle composite, namely TPNT1, which contains Au-NP (1 ppm), Ag-NP (5 ppm), ZnO-NP (60 ppm) and ClO2 (42.5 ppm) in aqueous solution was prepared and characterized by spectroscopy, transmission electron microscopy, dynamic light scattering analysis and potentiometric titration. Based on the in vitro cell-based assay, TPNT1 inhibited six major clades of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with effective concentration within the range to be used as food additives. TPNT1 was shown to block viral entry by inhibiting the binding of SARS-CoV-2 spike proteins to the angiotensin-converting enzyme 2 (ACE2) receptor and to interfere with the syncytium formation. In addition, TPNT1 also effectively reduced the cytopathic effects induced by human (H1N1) and avian (H5N1) influenza viruses, including the wild-type and oseltamivir-resistant virus isolates. Together with previously demonstrated efficacy as antimicrobials, TPNT1 can block viral entry and inhibit or prevent viral infection to provide prophylactic effects against both SARS-CoV-2 and opportunistic infections.


Asunto(s)
Oro/farmacología , Subtipo H1N1 del Virus de la Influenza A/fisiología , Subtipo H5N1 del Virus de la Influenza A/fisiología , Plata/farmacología , Óxido de Zinc/farmacología , /metabolismo , Antivirales/química , Antivirales/farmacología , Farmacorresistencia Viral/efectos de los fármacos , Aditivos Alimentarios/farmacología , Oro/química , Células HEK293 , Humanos , Subtipo H1N1 del Virus de la Influenza A/efectos de los fármacos , Subtipo H5N1 del Virus de la Influenza A/efectos de los fármacos , Nanopartículas del Metal/química , Nanocompuestos/química , Oseltamivir/farmacología , Tamaño de la Partícula , Unión Proteica/efectos de los fármacos , Plata/química , Glicoproteína de la Espiga del Coronavirus/metabolismo , Internalización del Virus/efectos de los fármacos , Óxido de Zinc/química
4.
Int J Mol Sci ; 22(4)2021 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-33672995

RESUMEN

Multidrug-resistant (MDR) bacteria constitute a global health issue. Over the past ten years, interest in nanoparticles, particularly metallic ones, has grown as potential antibacterial candidates. However, as there is no consensus about the procedure to characterize the metallic nanoparticles (MNPs; i.e., metallic aggregates) and evaluate their antibacterial activity, it is impossible to conclude about their real effectiveness as a new antibacterial agent. To give part of the answer to this question, 12 nm gold and silver nanoparticles have been prepared by a chemical approach. After their characterization by transmission electronic microscopy (TEM), Dynamic Light Scattering (DLS), and UltraViolet-visible (UV-vis) spectroscopy, their surface accessibility was tested through the catalytic reduction of the 4-nitrophenol, and their stability in bacterial culture medium was studied. Finally, the antibacterial activities of 12 nm gold and silver nanoparticles facing Staphylococcus aureus and Escherichia coli have been evaluated using the broth microdilution method. The results show that gold nanoparticles have a weak antibacterial activity (i.e., slight inhibition of bacterial growth) against the two bacteria tested. In contrast, silver nanoparticles have no activity on S. aureus but demonstrate a high antibacterial activity against Escherichia coli, with a minimum inhibitory concentration of 128 µmol/L. This high antibacterial activity is also maintained against two MDR-E. coli strains.


Asunto(s)
Antibacterianos/toxicidad , Escherichia coli/efectos de los fármacos , Oro/química , Nanopartículas del Metal/toxicidad , Plata/química , Staphylococcus aureus/efectos de los fármacos , Antibacterianos/química , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Dispersión Dinámica de Luz , Escherichia coli/crecimiento & desarrollo , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Pruebas de Sensibilidad Microbiana/métodos , Microscopía Electrónica de Transmisión , Espectrofotometría , Staphylococcus aureus/crecimiento & desarrollo
5.
Molecules ; 26(4)2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33671921

RESUMEN

Coinage metal(I)···metal(I) interactions are widely of interest in fields such as supramolecular assembly and unique luminescent properties, etc. Only two types of polynuclear silver(I) pyrazolato complexes have been reported, however, and no detailed spectroscopic characterizations have been reported. An unexpected synthetic method yielded a polynuclear silver(I) complex [Ag(µ-L1Clpz)]n (L1Clpz- = 4-chloride-3,5-diisopropyl-1-pyrazolate anion) by the reaction of {[Ag(µ-L1Clpz)]3}2 with (nBu4N)[Ag(CN)2]. The obtained structure was compared with the known hexanuclear silver(I) complex {[Ag(µ-L1Clpz)]3}2. The Ag···Ag distances in [Ag(µ-L1Clpz)]n are slightly shorter than twice Bondi's van der Waals radius, indicating some Ag···Ag argentophilic interactions. Two Ag-N distances in [Ag(µ-L1Clpz)]n were found: 2.0760(13) and 2.0716(13) Å, and their N-Ag-N bond angles of 180.00(7)° and 179.83(5)° indicate that each silver(I) ion is coordinated by two pyrazolyl nitrogen atoms with an almost linear coordination. Every five pyrazoles point in the same direction to form a 1-D zig-zag structure. Some spectroscopic properties of [Ag(µ-L1Clpz)]n in the solid-state are different from those of {[Ag(µ-L1Clpz)]3}2 (especially in the absorption and emission spectra), presumably attributable to this zig-zag structure having longer but differently arranged intramolecular Ag···Ag interactions of 3.39171(17) Å. This result clearly demonstrates the different physicochemical properties in the solid-state between 1-D coordination polymer and metalacyclic trinuclear (hexanuclear) or tetranuclear silver(I) pyrazolate complexes.


Asunto(s)
Polímeros/síntesis química , Pirazoles/síntesis química , Plata/química , Cristalografía por Rayos X , Luminiscencia , Conformación Molecular , Polímeros/química , Pirazoles/química , Espectrofotometría Ultravioleta , Temperatura
6.
ACS Sens ; 6(3): 613-627, 2021 03 26.
Artículo en Inglés | MEDLINE | ID: mdl-33660987

RESUMEN

Viruses have caused significant damage to the world. Effective detection is required to relieve the impact of viral infections. A biomolecule can be used as a template such as deoxyribonucleic acid (DNA), peptide, or protein, for the growth of silver nanoclusters (AgNCs) and for recognizing a virus. Both the AgNCs and the recognition elements are tunable, which is promising for the analysis of new viruses. Considering that a new virus such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) urgently requires a facile sensing strategy, various virus detection strategies based on AgNCs including fluorescence enhancement, color change, quenching, and recovery are summarized. Particular emphasis is placed on the molecular analysis of viruses using DNA stabilized AgNCs (DNA-AgNCs), which detect the virus's genetic material. The more widespread applications of AgNCs for general virus detection are also discussed. Further development of these technologies may address the challenge for facile detection of SARS-CoV-2.


Asunto(s)
Técnicas Biosensibles , ADN Viral/química , Nanopartículas del Metal/química , Plata/química , Virus/genética , Fluorescencia , Humanos
7.
Molecules ; 26(5)2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33668169

RESUMEN

A series of fifteen silver (I) quinoline complexes Q1-Q15 have been synthesized and studied for their biological activities. Q1-Q15 were synthesized from the reactions of quinolinyl Schiff base derivatives L1-L5 (obtained by condensing 2-quinolinecarboxaldehyde with various aniline derivatives) with AgNO3, AgClO4 and AgCF3SO3. Q1-Q15 were characterized by various spectroscopic techniques and the structures of [Ag(L1)2]NO3Q1, [Ag(L1)2]ClO4Q6, [Ag(L2)2]ClO4Q7, [Ag(L2)2]CF3SO3Q12 and [Ag(L4)2]CF3SO3Q14 were unequivocally determined by single crystal X-ray diffraction analysis. In vitro antimicrobial tests against Gram-positive and Gram-negative bacteria revealed the influence of structure and anion on the complexes' moderate to excellent antibacterial activity. In vitro antioxidant activities of the complexes showed their good radical scavenging activity in ferric reducing antioxidant power (FRAP). Complexes with the fluorine substituent or the thiophene or benzothiazole moieties are more potent with IC50 between 0.95 and 2.22 mg/mL than the standard used, ascorbic acid (2.68 mg/mL). The compounds showed a strong binding affinity with calf thymus-DNA via an intercalation mode and protein through a static quenching mechanism. Cytotoxicity activity was examined against three carcinoma cell lines (HELA, MDA-MB231, and SHSY5Y). [Ag(L2)2]ClO4Q7 with a benzothiazole moiety and [Ag(L4)2]ClO4Q9 with a methyl substituent had excellent cytotoxicity against HELA cells.


Asunto(s)
Antibacterianos/farmacología , Antineoplásicos/farmacología , Antioxidantes/farmacología , Complejos de Coordinación/farmacología , ADN/química , Antibacterianos/síntesis química , Antibacterianos/química , Antineoplásicos/síntesis química , Antineoplásicos/química , Antioxidantes/síntesis química , Antioxidantes/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Ensayos de Selección de Medicamentos Antitumorales , Compuestos Férricos/antagonistas & inhibidores , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Oxidación-Reducción , Quinolinas/química , Quinolinas/farmacología , Bases de Schiff/química , Bases de Schiff/farmacología , Plata/química , Plata/farmacología
8.
Molecules ; 26(4)2021 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-33672102

RESUMEN

Macroalgae are sources of bioactive compounds that are interesting from both a chemical and a medical point of view. Although their use in biomedicine has increased significantly in recent years, tests conducted to date have been mostly related to species from temperate latitudes, with the potential application of Antarctic biodiversity being minor. The wide variety of algae species present on Antarctic coastal areas can be a source of new antioxidants. Bearing this in mind, the brown macroalgae Desmarestia antarctica (DA) and the red Iridaea cordata (IC) were selected for the preparation of aqueous extracts with the aim of analyzing their antioxidant activity. This analysis was performed by determining reducing power, total phenolic content, and 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity. Furthermore, both extracts were employed to synthesize gold and silver nanoparticles. The nanomaterials were fully characterized by means of UV-Visible spectroscopy, transmission electron microscopy, Z potential measurements, and Fourier transform infrared spectroscopy, which confirmed the formation of stable, spherical nanoparticles with mean diameters of 13.7 ± 3.1 and 17.5 ± 3.7 nm for Ag@DA and Ag@IC and 12.6 ± 1.9 and 12.3 ± 1.6 nm for Au@DA and Au@IC. Antioxidant assays were performed after the synthesis of the nanomaterials to evaluate their possible synergistic effect with the extracts. The results suggest that polysaccharides and proteins may play a key role in the process of reduction and stabilization. Finally, for the sake of comparison, the results obtained for the Antarctic macroalgae Desmarestia menziesii and Palmaria decipiens have also been considered in the present work.


Asunto(s)
Antioxidantes/farmacología , Oro/metabolismo , Nanopartículas del Metal/química , Phaeophyta/química , Rhodophyta/química , Plata/metabolismo , Regiones Antárticas , Antioxidantes/síntesis química , Antioxidantes/química , Compuestos de Bifenilo/antagonistas & inhibidores , Oro/química , Tamaño de la Partícula , Picratos/antagonistas & inhibidores , Plata/química
9.
Carbohydr Polym ; 260: 117835, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712172

RESUMEN

Bacterial breeding is the main cause of food perishability, which is harmful to human health. Silver nanoparticles (AgNPs) are one of the most widely used antimicrobial agents, but they are easy to release and cause cumulative toxicity. In this work, with corn stalk as green reductant and GO as template, a simple electrostatic self-assembled sandwich-like chitosan (CS) wrapped rGO@AgNPs nanocomposite film (CS/rGO@AgNPs) was synthesized to achieve stabilizing and controlled-release of AgNPs. The results showed that the the CS/rGO@AgNPs film continued releasing AgNPs for up to 14 days, and the final release amount of silver nanoparticles was only about 1.9 %. More importantly, the nanocomposite film showed durable antibacterial effect and good antibacterial activity against E. coli and S. aureus, and they showed no toxicity to cells. Hence, the nanocomposite film has potential application as an effective and safe packaging material to prolong the shelf life of food products.


Asunto(s)
Antibacterianos/química , Quitosano/química , Grafito/química , Nanopartículas del Metal/química , Nanocompuestos/química , Antibacterianos/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Escherichia coli/efectos de los fármacos , Humanos , Nanocompuestos/toxicidad , Plata/química , Solubilidad , Staphylococcus aureus/efectos de los fármacos , Resistencia a la Tracción
10.
Int J Nanomedicine ; 16: 2187-2201, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33758506

RESUMEN

The physicochemical and optical properties of silver nanoparticles (SNPs) and gold nanoparticles (GNPs) have allowed them to be employed for various biomedical applications, including delivery, therapy, imaging, and as theranostic agents. However, since they are foreign body systems, they are usually redistributed and accumulated in some vital organs, which can produce toxic effects; therefore, this a crucial issue that should be considered for potential clinical trials. This review aimed to summarize the reports from the past ten years that have used SNPs and GNPs for in vivo studies on the diagnosis and treatment of brain diseases and those related to the central nervous system, emphasizing their toxicity as a crucial topic address. The article focuses on the effect of the nanoparticle´s size and chemical composition as relevant parameters for in vivo toxicity. At the beginning of this review, the general toxicity and distribution studies are discussed separately for SNPs and GNPs. Subsequently, this manuscript analyzes the principal applications of both kinds of nanoparticles for glioma, neurodegenerative, and other brain diseases, and discusses the advances in clinical trials. Finally, we analyze research prospects towards clinical applications for both types of metallic nanoparticles.


Asunto(s)
Enfermedades del Sistema Nervioso Central/patología , Oro/química , Nanopartículas del Metal/química , Nanopartículas del Metal/toxicidad , Tamaño de la Partícula , Plata/química , Pruebas de Toxicidad , Animales , Humanos , Nanopartículas del Metal/ultraestructura , Distribución Tisular/efectos de los fármacos
11.
Carbohydr Polym ; 260: 117772, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712130

RESUMEN

Nanoparticle-polymer composites are important functional materials but structural control of their assembly is challenging. Owing to its crystalline internal structure and tunable nanoscale morphology, cellulose is promising polymer scaffold for templating such composite materials. Here, we show bottom-up synthesis of reducing end thiol-modified cellulose chains by iterative bi-enzymatic ß-1,4-glycosylation of 1-thio-ß-d-glucose (10 mM), to a degree of polymerization of ∼8 and in a yield of ∼41% on the donor substrate (α-d-glucose 1-phosphate, 100 mM). Synthetic cellulose oligomers self-assemble into highly ordered crystalline (cellulose allomorph II) material showing long (micrometers) and thin nanosheet-like morphologies, with thickness of 5-7 nm. Silver nanoparticles were attached selectively and well dispersed on the surface of the thiol-modified cellulose, in excellent yield (≥ 95%) and high loading efficiency (∼2.2 g silver/g thiol-cellulose). Examined against Escherichia coli and Staphylococcus aureus, surface-patterned nanoparticles show excellent biocidal activity. Bottom-up approach by chemical design to a functional cellulose nanocomposite is presented. Synthetic thiol-containing nanocellulose can expand the scope of top-down produced cellulose materials.


Asunto(s)
Antibacterianos/química , Celulosa/química , Nanopartículas del Metal/química , Nanocompuestos/química , Compuestos de Sulfhidrilo/química , Antibacterianos/farmacología , Pruebas Antimicrobianas de Difusión por Disco , Escherichia coli/efectos de los fármacos , Nanocompuestos/toxicidad , Plata/química , Staphylococcus aureus/efectos de los fármacos
12.
Int J Nanomedicine ; 16: 1901-1911, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33707945

RESUMEN

Purpose: Developing a sensitive SERS-based method to quantitatively detect serum biomarkers (Aß1-42 and P-Tau-181) for the early diagnosis of Alzheimer's disease (AD). Methods: In this study, a novel SERS-based sandwich immunoassay, which consists of tannin-capped silver nanoparticles and magnetic graphene oxide (Fe3O4@GOs), was developed. We firstly applied this method for the detection of protein standards in buffer solution, obtaining the regression equation. Then, its potential value on real serum samples of AD was further explored. Results: The detection linear range of Aß1-42 and P-Tau-181 protein standards were observed to range from 100 pg mL-1 to 10 fg mL-1, 100 pg mL-1 to 1 fg mL-1 respectively. We finally explored clinical application of the proposed method in 63 serum samples. As a result, P-tau-181 differentiated AD from non-AD dementia patients (AUC = 0.770), with a more favored ROC than Aß1-42 (AUC = 0.383). Conclusion: The developed SERS-based immunoassay is successfully applied to the determination of Aß1-42 and P-Tau-181 in human serum specimens, which provides a promising tool for the early diagnosis of AD.


Asunto(s)
Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/diagnóstico , Biomarcadores/sangre , Inmunoensayo/métodos , Sondas Moleculares/química , Plata/química , Espectrometría Raman/métodos , Péptidos beta-Amiloides/sangre , Benzoatos/química , Calibración , Femenino , Grafito/química , Humanos , Límite de Detección , Masculino , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Compuestos de Sulfhidrilo/química , Difracción de Rayos X , Proteínas tau/sangre
13.
Int J Mol Sci ; 22(4)2021 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-33670386

RESUMEN

Sequence-specific nucleic acids exhibiting selective recognition properties towards low-molecular-weight substrates and macromolecules (aptamers) find growing interest as functional biopolymers for analysis, medical applications such as imaging, drug delivery and even therapeutic agents, nanotechnology, material science and more. The present perspective article introduces a glossary of examples for diverse applications of aptamers mainly originated from our laboratory. These include the introduction of aptamer-functionalized nanomaterials such as graphene oxide, Ag nanoclusters and semiconductor quantum dots as functional hybrid nanomaterials for optical sensing of target analytes. The use of aptamer-functionalized DNA tetrahedra nanostructures for multiplex analysis and aptamer-loaded metal-organic framework nanoparticles acting as sense-and-treat are introduced. Aptamer-functionalized nano and microcarriers are presented as stimuli-responsive hybrid drug carriers for controlled and targeted drug release, including aptamer-functionalized SiO2 nanoparticles, carbon dots, metal-organic frameworks and microcapsules. A further application of aptamers involves the conjugation of aptamers to catalytic units as a means to mimic enzyme functions "nucleoapzymes". In addition, the formation and dissociation of aptamer-ligand complexes are applied to develop mechanical molecular devices and to switch nanostructures such as origami scaffolds. Finally, the article discusses future challenges in applying aptamers in material science, nanotechnology and catalysis.


Asunto(s)
Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/uso terapéutico , Sistemas de Liberación de Medicamentos , Nanoestructuras/química , Nanoestructuras/uso terapéutico , Animales , Catálisis , Humanos , Plata/química , Plata/uso terapéutico
14.
Int J Mol Sci ; 22(4)2021 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-33546211

RESUMEN

In a previous article, we reported on the higher toxicity of silver(I) complexes of miconazole [Ag(MCZ)2NO3 (1)] and [Ag(MCZ)2ClO4 (2)] in HepG2 tumor cells compared to the corresponding salts of silver, miconazole and cisplatin. Here, we present the synthesis of two silver(I) complexes of miconazole containing two new counter ions in the form of Ag(MCZ)2X (MCZ = 1-[2-(2,4-dichlorobenzyloxy)-2-(2,4-dichlorophenyl)ethyl]-1H-imidazole]; X = BF4- (3), SbF6- (4)). The novel silver(I) complexes were characterized by elemental analysis, 1H NMR, 13C NMR and infrared (IR) spectroscopy, electrospray ionization (ESI)-MS spectrometry and X-ray-crystallography. In the present study, the antimicrobial activity of all obtained silver(I) complexes of miconazole against six strains of Gram-positive bacteria, five strains of Gram-negative bacteria and yeasts was evaluated. The results were compared with those of a silver sulfadiazine drug, the corresponding silver salts and the free ligand. Silver(I) complexes exhibited significant activity against Gram-positive bacteria, which was much better than that of silver sulfadiazine and silver salts. The highest antimicrobial activity was observed for the complex containing the nitrate counter ion. All Ag(I) complexes of miconazole resulted in much better inhibition of yeast growth than silver sulfadiazine, silver salts and miconazole. Moreover, the synthesized silver(I) complexes showed good or moderate activity against Gram-negative bacteria compared to the free ligand.


Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Complejos de Coordinación/síntesis química , Miconazol/química , Plata/química , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Levaduras/efectos de los fármacos
15.
Int J Mol Sci ; 22(4)2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33578653

RESUMEN

We present a template-assisted method for synthesizing nanogap shell structures for biomolecular detections based on surface-enhanced Raman scattering. The interior nanogap-containing a silver shell structure, referred to as a silver nanogap shell (Ag NGS), was fabricated on silver nanoparticles (Ag NPs)-coated silica, by adsorbing small aromatic thiol molecules on the Ag NPs. The Ag NGSs showed a high enhancement factor and good signal uniformity, using 785-nm excitation. We performed in vitro immunoassays using a prostate-specific antigen as a model cancer biomarker with a detection limit of 2 pg/mL. To demonstrate the versatility of Ag NGS nanoprobes, extracellular duplex surface-enhanced Raman scattering (SERS) imaging was also performed to evaluate the co-expression of cancer biomarkers, human epidermal growth factor-2 (HER2) and epidermal growth factor receptor (EGFR), in a non-small cell lung cancer cell line (H522). Developing highly sensitive Ag NGS nanoprobes that enable multiplex biomolecular detection and imaging can open up new possibilities for point-of-care diagnostics and provide appropriate treatment options and prognosis.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Nanopartículas del Metal/química , Receptor ErbB-2/análisis , Plata/química , Biomarcadores de Tumor/análisis , Línea Celular Tumoral , Receptores ErbB/análisis , Humanos , Nanopartículas del Metal/ultraestructura , Espectrometría Raman/métodos
16.
Molecules ; 26(4)2021 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-33562272

RESUMEN

For many antibacterial polymer fibres, especially for those with natural functional additives, the antibacterial response might not last over time. Moreover, the mechanical performance of polymeric fibres degrades significantly during the intended operation, such as usage in textile and industrial filter applications. The degradation process and overall ageing can lead to emitted volatile organic compounds (VOCs). This work focused on the usage of pine rosin as natural antibacterial chemical and analysed the weathering of melt-spun polyethylene (PE) and poly lactic acid (PLA) polyfilaments. A selected copolymer surfactant, as an additional chemical, was studied to better integrate rosin with the molecular structure of the plastics. The results reveal that a high 20 w-% of rosin content can be obtained by surfactant addition in non-oriented PE and PLA melt-spun polyfilaments. According to the VOC analysis, interestingly, the total emissions from the melt-spun PE and PLA fibres were lower for rosin-modified (10 w-%) fibres and when analysed below 60 ℃. The PE fibres of the polyfilaments were found to be clearly more durable in terms of the entire weathering study, i.e., five weeks of ultraviolet radiation, thermal ageing and standard washing. The antibacterial response against Gram-positive Staphylococcus aureus by the rosin-containing fibres was determined to be at the same level (decrease of 3-5 logs cfu/mL) as when using 1.0 w-% of commercial silver-containing antimicrobial. For the PE polyfilaments with rosin (10 w-%), full killing response (decrease of 3-5 logs cfu/mL) remained after four weeks of accelerated ageing at 60 ℃.


Asunto(s)
Antibacterianos/química , Polietileno/química , Resinas de Plantas/química , Compuestos Orgánicos Volátiles/química , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Pinus/química , Plásticos/química , Plásticos/farmacología , Poliésteres/química , Polietileno/farmacología , Polímeros/química , Polímeros/farmacología , Plata/química , Staphylococcus aureus/efectos de los fármacos , Textiles/análisis , Compuestos Orgánicos Volátiles/farmacología
17.
Nat Commun ; 12(1): 1292, 2021 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-33637710

RESUMEN

Surface-enhanced Raman spectroscopy (SERS) has emerged as a powerful tool to detect biomolecules in aqueous environments. However, it is challenging to identify protein structures at low concentrations, especially for the proteins existing in an equilibrium mixture of various conformations. Here, we develop an in situ optical tweezers-coupled Raman spectroscopy to visualize and control the hotspot between two Ag nanoparticle-coated silica beads, generating tunable and reproducible SERS enhancements with single-molecule level sensitivity. This dynamic SERS detection window is placed in a microfluidic flow chamber to detect the passing-by proteins, which precisely characterizes the structures of three globular proteins without perturbation to their native states. Moreover, it directly identifies the structural features of the transient species of alpha-synuclein among its predominant monomers at physiological concentration of 1 µM by reducing the ensemble averaging. Hence, this SERS platform holds the promise to resolve the structural details of dynamic, heterogeneous, and complex biological systems.


Asunto(s)
Pinzas Ópticas , Proteínas/química , Espectrometría Raman/métodos , Nanopartículas del Metal/química , Microfluídica , Muramidasa/química , Proteínas/metabolismo , Dióxido de Silicio/química , Plata/química , Propiedades de Superficie
18.
Food Chem ; 350: 129025, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33609938

RESUMEN

Silver-coated gold nanoparticles (Au@AgNPs) were optimized with different gold (Au) core sizes and modified surface with mercaptooctane (MCO) to determine fungicide residues in pear fruit extracts. The developed MCO/Au@AgNPs with a gold core size of 28 nm and silver shell thickness of 6 nm exhibited high sensitivity and significant enhancement of Raman scattering in detecting tricyclazole (TCZ) and thiram fungicides in standard and pear fruit samples. The detection limits for TCZ and thiram in the pear fruit extracts were 0.005 and 0.003 ppm with coefficients of determination of (R2) of 0.9984 and 0.9971, percent recovery ranging from 82.7 to 107.4% and 80.7 to 109.8%, and relative standard deviation (RSD) of 1.5 to 7.9% and 3.7 to 9.5%, respectively. Results showed that this easily prepared method could be employed as SERS active platforms for the rapid assessment of trace contaminants of agrochemicals in agriculture production.


Asunto(s)
Fungicidas Industriales/análisis , Oro/química , Nanopartículas del Metal/química , Pyrus/química , Plata/química , Tiazoles/química , Tiram/análisis , Límite de Detección , Extractos Vegetales/análisis , Reproducibilidad de los Resultados , Espectrometría Raman/métodos
19.
Food Chem ; 351: 129252, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33626469

RESUMEN

Herein, an innovative enzyme free electrochemiluminescence chlorpyrifos sensor was reported based on the incorporation of ternary nanocomposite (ruthenium nanobeads/silver nanoparticles/graphene oxide) on the surface of glassy carbon electrode. The silver nanoparticles as a robust signal enhancing agent were well deposited on the modified graphene oxide/glassy carbon electrode and exhibited supreme electrocatalytic proficiency. Then, Ru(bipy)32+ species in bead-like nanoparticles were uniformly anchored on the surface of the modified electrode with the help of chitosan, as a good crosslinking agent. Boron nitride quantum dots as a new coreactant species showed the excellent proficiency for signal enhancement of the fabricated electrode. The fabricated electrode was successfully used as an ultra-sensitive sensor for trace analysis of chlorpyrifos by ECL technique. The wide linear range and the low detection limit were obtained from 5.0 × 10-15 to 4.2 × 10-9 M and 6.5 × 10-16 M, respectively.


Asunto(s)
Cloropirifos/análisis , Técnicas Electroquímicas/métodos , Mediciones Luminiscentes/métodos , Nanocompuestos/química , Compuestos de Boro/química , Catálisis , Técnicas Electroquímicas/instrumentación , Electrodos , Grafito/química , Límite de Detección , Mediciones Luminiscentes/instrumentación , Nanopartículas del Metal/química , Puntos Cuánticos/química , Rutenio/química , Plata/química
20.
Life Sci ; 272: 119262, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33639151

RESUMEN

The perpetual lack of advanced strategies to prevent aggressive breast cancer with multiple categories represents challenging scientific society problems. Reduced graphene oxide- can treat disease, which was recently investigated due to its ability to induce apoptosis-based death. This research tested the chemotherapeutics in vitro efficacy of reduced graphene oxide embedded with gold and silver nanoparticles toward drug-sensitive breast cancer cells (MCF-7) and their cytotoxicity. Synthesis of the Au-Ag/rGO-5FU nanocomposites has been conducted using a wet chemical approach with chitosan aid as a pore directing and capping agent. The particle structure and morphology well characterized using different systems. HR-TEM shows a narrow-sized distribution of less than 100 nm, which is proper for cell membranes and medical use. The physical combination of the nanocomposite and 5-FU drug has been conducted mechanically using wet chemistry. The Au/Ag/rGO-5FU material's high activity enables it to produce reactive oxygen radicals, which display a potential against MCF-7 cell lines. All the results, including those obtained via cytometry, use the combination of Au/Ag/rGO-5FU to show a more substantial anticancer influence and more drug stability than pure 5-FU.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Oro/farmacología , Grafito/farmacología , Plata/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Fluorouracilo/farmacología , Oro/química , Grafito/metabolismo , Humanos , Células MCF-7 , Nanopartículas del Metal/química , Nanopartículas del Metal/uso terapéutico , Nanocompuestos/química , Especies Reactivas de Oxígeno/metabolismo , Plata/química
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