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1.
Top Curr Chem (Cham) ; 378(2): 29, 2020 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-32125542

RESUMEN

The efficacy of photocatalysis strongly depends on the activity of the catalysts and the operational factors, especially factors associated with mass transfer and the possibility of catalyst deactivation. The use of ultrasound has great potential to enhance catalyst activity, during both the synthesis and actual oxidation processes due to the cavitational effects of turbulence and liquid streaming. This article presents an overview of the application aspects of ultrasound, both in the synthesis of the photocatalyst and applications for wastewater treatment. A review of the literature revealed that the use of ultrasound in the synthesis processes can result in a catalyst with a lower mean size and higher surface area as well as uniform size distribution. The application of ultrasound in the actual photocatalytic oxidation facilitates enhancement of the oxidation capacity, leading to higher degradation rates, sometimes synergistic results and definitely lower treatment times. This article also presents guidelines for the selection of the best operating conditions for the use of ultrasound in photocatalytic systems and includes a discussion on the possible reactor configurations suitable for large-scale operations. Overall, a combination of ultrasound with photocatalytic oxidation or the optimized application of ultrasound in catalyst synthesis can yield significant benefits.


Asunto(s)
Sonicación , Rayos Ultravioleta , Catálisis , Metales/química , Nanopartículas/química , Oxidación-Reducción , Óxidos/química , Fotólisis/efectos de la radiación , Contaminantes Químicos del Agua/química
2.
Anticancer Res ; 40(2): 689-694, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32014909

RESUMEN

BACKGROUND/AIM: Piperine, a major alkaloid of the fruit of black pepper plants, selectively inhibits the growth of triple-negative breast cancer cells but its lipophilicity restricts possible clinical application. This study therefore determined the feasibility of encapsulating piperine in nanoparticles (NPs) to increase its solubility in an aqueous environment. MATERIALS AND METHODS: Piperine-loaded biodegradable methoxy poly(ethylene glycol)-poly(lactic-co-glycolic) acid copolymer-based NPs were produced by single emulsion solvent extraction and thin-film hydration. Growth and viability of triple-negative breast cancer (TNBC) cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin-V-FLUOS/propidium iodide staining, respectively. RESULTS: Thin-film hydration was superior to single emulsion solvent extraction, yielding piperine-loaded NPs with an average size of 50 nm. Piperine-loaded NPs inhibited TNBC cell growth and induced apoptosis while sparing normal fibroblasts. CONCLUSION: It is feasible to deliver a cytotoxic concentration of piperine to TNBC cells via NPs with the potential for improved bioavailability and solubility in biological fluids.


Asunto(s)
Alcaloides/administración & dosificación , Benzodioxoles/administración & dosificación , Nanopartículas/administración & dosificación , Piperidinas/administración & dosificación , Alcamidas Poliinsaturadas/administración & dosificación , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Alcaloides/química , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/química , Apoptosis/efectos de los fármacos , Benzodioxoles/química , Línea Celular Tumoral , Emulsiones/administración & dosificación , Emulsiones/química , Femenino , Humanos , Nanopartículas/química , Piperidinas/química , Poliésteres/administración & dosificación , Poliésteres/química , Polietilenglicoles/administración & dosificación , Polietilenglicoles/química , Alcamidas Poliinsaturadas/química , Neoplasias de la Mama Triple Negativas/patología
3.
J Agric Food Chem ; 68(9): 2795-2802, 2020 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-32031786

RESUMEN

Polydopamine (PDA) possesses high aqueous dispersibility, strong optical absorption, and a zwitterionic property, which give it multitudes of advantages to coat light-sensitive hydrophobic curcumin (Cur) for pH-responsive release. However, PDA is formed in alkaline conditions, which hinders its potential application for alkali-sensitive curcumin coating. Here, we developed a method to prepare PDA-coated Cur nanoparticles (NPs), which reduced chemical degradation of Cur in alkaline conditions. Encapsulation efficiency and loading capacity decreased to 73.69% and 51.80%, as the time for dopamine polymerization went on. PDA could protect Cur from light-induced degradation in powder and solution forms. Controlled release and pH-responsive delivery of PDA-coated Cur were observed under stomach and intestinal conditions compared to free Cur, which resulted from the coverage and thickness of the PDA shell and the electrostatic attraction between PDA and Cur. PDA-coated Cur NPs could be a promising way for the application of Cur in the beverage and food industry.


Asunto(s)
Curcumina/química , Indoles/química , Nanopartículas/química , Polímeros/química , Portadores de Fármacos/química , Composición de Medicamentos , Concentración de Iones de Hidrógeno , Cinética , Tamaño de la Partícula
4.
Top Curr Chem (Cham) ; 378(1): 18, 2020 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-32009187

RESUMEN

DNA molecules with superior flexibility, affinity and programmability have garnered considerable attention for the controllable assembly of nanoparticles (NPs). By controlling the density, length and sequences of DNA on NPs, the configuration of NP assemblies can be rationally designed. The specific recognition of DNA enables changes to be made to the spatial structures of NP assemblies, resulting in differences in tailorable optical signals. Comprehensive information on the fabrication of DNA-driven NP assemblies would be beneficial for their application in biosensing and bioimaging. This review analyzes the progress of DNA-driven NP assemblies, and discusses the tunable configurations determined by the structural parameters of DNA skeletons. The collective optical properties, such as chirality, fluorescence and surface enhanced Raman resonance (SERS), etc., of DNA-driven NP assemblies are explored, and engineered tailorable optical properties of these spatial structures are achieved. We discuss the development of DNA-directed NP assemblies for the quantification of DNA, toxins, and heavy metal ions, and demonstrate their potential application in the biosensing and bioimaging of tumor markers, RNA, living metal ions and phototherapeutics. We hihghlight possible challenges in the development of DNA-driven NP assemblies, and further direct potential prospects in the practical applications of macroscopical materials and photonic devices.


Asunto(s)
Técnicas Biosensibles/métodos , ADN/química , Nanopartículas/química , Imagen Óptica/métodos , Biomarcadores de Tumor/análisis , Grafito/química , Humanos , Metales/química , Espectrometría Raman
6.
Chem Commun (Camb) ; 56(20): 3019-3022, 2020 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-32048647

RESUMEN

Nucleus-targeting NPs based on RuO2 (RuO2NPs) were developed by controlling the size and the surface charge of nanoparticles (NPs). This study not only demonstrates a facile approach for the fabrication of ultrasmall CS-RuO2NPs with good biocompatibility and excellent photothermal properties but also their unique potential for the nucleus-targeted low-temperature PTT.


Asunto(s)
Nanopartículas/química , Imagen Óptica , Óxidos/química , Técnicas Fotoacústicas , Rutenio/química , Temperatura Ambiental , Núcleo Celular/efectos de los fármacos , Humanos , Rayos Infrarrojos , Células MCF-7 , Óxidos/farmacología , Tamaño de la Partícula , Fototerapia , Rutenio/farmacología , Propiedades de Superficie
7.
Chem Commun (Camb) ; 56(21): 3183-3186, 2020 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-32067022

RESUMEN

A novel nanoarchitecture (MSN-Tb-UbR) was prepared by modifying rhodamine B-labelled Ubs (Ub-Rs) on the surface of mesoporous silica nanoparticles (MSNs) loaded with Tb3+-complexes. The MSN-Tb-UbR exhibits ratiometric sensing ability for DUB (UCH-L1) with good sensitivity and selectivity.


Asunto(s)
Nanopartículas/química , Dióxido de Silicio/química , Ubiquitina Tiolesterasa/análisis , Transferencia Resonante de Energía de Fluorescencia/métodos , Colorantes Fluorescentes/química , Porosidad , Rodaminas/química , Propiedades de Superficie , Terbio/química
8.
Life Sci ; 248: 117466, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32101760

RESUMEN

AIMS: Nanoparticles (NPs)-based drugs have been recently introduced to improve the efficacy of current therapeutic strategies for the treatment of cancer; however, the molecular mechanisms by which a NP interacts with cellular systems still need to be delineated. Here, we utilize the autophagic potential of TiO2 NPs for improving chemotherapeutic effects of 5-fluorouracil (5-FU) in human AGS gastric cells. MATERIALS AND METHODS: Cell growth and viability were determined by trypan blue exclusion test and MTT assay, respectively. Vesicular organelles formation was evaluated by acridine orange staining of cells. Cell cycle and apoptosis were monitored by flow cytometry. Reactive oxygen species (ROS) level were measured by DCHF-DA staining. Autophagy was examined by q-PCR and western blotting. Molecular docking was used for studying NP interaction with autophagic proteins. KEY FINDINGS: TiO2 NPs increase ROS production, impair lysosomal function and subsequently block autophagy flux in AGS cells. In addition, the autophagy blockade induced by non-toxic concentrations of TiO2 NPs (1 µg/ml) can promote cytotoxic and apoptotic effects of 5-FU in AGS cells. SIGNIFICANCE: These results confirm the beneficial effects of TiO2 NPs in combination with chemotherapy in in vitro model of gastric cancer, which may pave the way to develop a possible solution to circumvent chemoresistance in cancer.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacología , Autofagia/efectos de los fármacos , Fluorouracilo/farmacología , Regulación Neoplásica de la Expresión Génica , Nanopartículas/química , Titanio/farmacología , Antimetabolitos Antineoplásicos/química , Apoptosis/efectos de los fármacos , Apoptosis/genética , Autofagia/genética , Proteína 5 Relacionada con la Autofagia/genética , Proteína 5 Relacionada con la Autofagia/metabolismo , Proteína 7 Relacionada con la Autofagia/genética , Proteína 7 Relacionada con la Autofagia/metabolismo , Beclina-1/genética , Beclina-1/metabolismo , Ciclo Celular/efectos de los fármacos , Ciclo Celular/genética , Línea Celular Tumoral , Proliferación Celular , Vesículas Citoplasmáticas/efectos de los fármacos , Vesículas Citoplasmáticas/metabolismo , Sinergismo Farmacológico , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Células Epiteliales/patología , Fluorouracilo/química , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patología , Humanos , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Proteínas Asociadas a Microtúbulos/antagonistas & inhibidores , Proteínas Asociadas a Microtúbulos/química , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Simulación del Acoplamiento Molecular , Nanopartículas/ultraestructura , Conformación Proteica , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Especies Reactivas de Oxígeno/agonistas , Especies Reactivas de Oxígeno/metabolismo , Proteína Sequestosoma-1/antagonistas & inhibidores , Proteína Sequestosoma-1/genética , Proteína Sequestosoma-1/metabolismo , Titanio/química , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismo
9.
Chem Biol Interact ; 318: 108974, 2020 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-32032594

RESUMEN

AIM: The aim of this study was the synthesis of ion doped silica-based nanoparticles and the evaluation of their toxic effect on erythrocytes. MATERIALS & METHODS: Their synthesis was performed using the sol-gel method, by the progressive addition of calcium, magnesium and copper ions on pure silica nanoparticles. The toxicity evaluation was based on hemolysis, lipid peroxidation, ROS, H2O2 species and antioxidant enzyme production. RESULTS: The addition of Mg and Cu in the SNs presented better hemocompatibility by protecting erythrocytes from oxidative stress. CONCLUSION: Ion doping with magnesium in the investigated calcium silicate system induces a protective effect in erythrocyte membrane in compare with pure silica nanoparticles.


Asunto(s)
Cobre/toxicidad , Eritrocitos/efectos de los fármacos , Magnesio/toxicidad , Nanopartículas/química , Nanopartículas/toxicidad , Dióxido de Silicio/química , Células Cultivadas , Cobre/química , Eritrocitos/metabolismo , Glutatión/metabolismo , Humanos , Peróxido de Hidrógeno , Magnesio/química , Malondialdehído/metabolismo , Microscopía Electrónica de Transmisión , Espectroscopía Infrarroja por Transformada de Fourier
10.
J Agric Food Chem ; 68(7): 1986-1997, 2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-31986044

RESUMEN

In this study, the impact of cerium oxide nanoparticles on the nutritional value of tomato (Solanum lycopersicum) fruit grown in soil infested with Fusarium oxysporum f. sp. lycopersici was investigated in a greenhouse pot study. Three-week old seedlings of Bonny Best tomato plants were exposed by foliar and soil routes to nanoparticle CeO2 (NP CeO2) and cerium acetate (CeAc) at 0, 50, and 250 mg/L and transplanted into pots containing a soil mixture infested with the Fusarium wilt pathogen. Fruit biomass, water content, diameter, and nutritional content (lycopene, reducing and total sugar) along with elemental composition, including Ce, were evaluated. Fruit Ce concentration was below the detection limit in all treatments. Foliar exposure to NP CeO2 at 250 increased the fruit dry weight (67%) and lycopene content (9%) in infested plants, compared with the infested untreated control. Foliar exposure to CeAc at 50 mg/L reduced fruit fresh weight (46%) and water content (46%) and increased the fruit lycopene content by 11% via root exposure as compared with the untreated infested control. At 250 mg/L, CeAc increased fruit dry weight (94%), compared with the infested untreated control. Total sugar content decreased in fruits of infested plants exposed via roots to NP CeO2 at 50 mg/kg (63%) and 250 mg/kg (54%), CeAc at 50 mg/kg (46%), and foliarly at 50 mg/L (50%) and 250 mg/L (50%), all compared with the infested untreated control. Plants grown in Fusarium-infested soil had decreased fruit dry weight (42%) and lycopene content (17%) and increased total sugar (60%) and Ca content (140%), when compared with the noninfested untreated control (p ≤ 0.05). Overall, the data suggested minimal negative effects of NP CeO2 on the nutritional value of tomato fruit while simultaneously suppressing Fusarium wilt disease.


Asunto(s)
Cerio/farmacología , Frutas/química , Fungicidas Industriales/farmacología , Fusarium/fisiología , Lycopersicon esculentum/microbiología , Enfermedades de las Plantas/microbiología , Frutas/efectos de los fármacos , Frutas/crecimiento & desarrollo , Frutas/microbiología , Fusarium/efectos de los fármacos , Lycopersicon esculentum/química , Lycopersicon esculentum/efectos de los fármacos , Lycopersicon esculentum/crecimiento & desarrollo , Nanopartículas/química , Valor Nutritivo , Suelo/química , Microbiología del Suelo
11.
Photochem Photobiol Sci ; 19(1): 29-33, 2020 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-31932832

RESUMEN

We demonstrate amyloid fibril (AF) decomposition induced by NIR-active upconversion nanoparticles complexed with photosensitisers. The process is triggered by upconversion, which initiates a photochemical reaction cascade that culminates in the generation of the highly reactive singlet-oxygen product 1O2 close to the amyloid superstructures, resulting in AF decomposition.


Asunto(s)
Amiloide/antagonistas & inhibidores , Nanopartículas/química , Fármacos Fotosensibilizantes/farmacología , Amiloide/metabolismo , Humanos , Rayos Infrarrojos
12.
Chem Commun (Camb) ; 56(8): 1255-1258, 2020 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-31898700

RESUMEN

Here we demonstrated that the stiffness of cationized gelatin nanoparticles determined the efficiency of RNAi in myeloid leukemia cells when the particle size and surface charges were kept constant. The siRNA delivery system with an elastic modulus of 0.87 MPa showed the largest siRNA uptake and RNAi efficiency for hard-to-transfect suspension cells.


Asunto(s)
Gelatina/química , Leucemia Mieloide/patología , Nanopartículas/química , Interferencia de ARN , Cationes/química , Supervivencia Celular/efectos de los fármacos , Sistemas de Liberación de Medicamentos , Humanos , Células K562 , Leucemia Mieloide/tratamiento farmacológico , Tamaño de la Partícula , ARN Interferente Pequeño/química , ARN Interferente Pequeño/farmacología , Propiedades de Superficie
13.
J Agric Food Chem ; 68(5): 1405-1418, 2020 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-31940190

RESUMEN

The aim of this study was to develop a novel system for the co-delivery of resveratrol and coenzyme Q10 (CoQ10). It was achieved with a combination of resveratrol-loaded composite nanoparticles and CoQ10-loaded Pickering emulsions. Different levels of resveratrol (0.05-0.30%, w/v) were entrapped into composite nanoparticles by the method of emulsification-evaporation. The size of composite nanoparticles was around 300-600 nm, and the maximum loading capacity of resveratrol was up to 13.88% (w/w). Hydrogen bonds, hydrophobic effects, and electrostatic attraction participated in the self-assembly of composite nanoparticles. The stability of CoQ10 Pickering emulsions was monitored under simulated environmental stresses (pH, ionic strength, UV radiation, and heat) and accelerated storage conditions. The physical stability of Pickering emulsions was dependent on the particle compositions, and the CoQ10 entrapped was also protected by the resveratrol-loaded nanoparticles. The morphology of Pickering emulsions was observed with the aid of optical microscopy, confocal laser scanning microscopy, and cryo-scanning electronic microscopy. The nutraceutical Pickering emulsions were designed for the co-delivery of resveratrol and CoQ10, which has the potential to be a novel vehicle for bioactive ingredients.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Nanopartículas/química , Resveratrol/química , Ubiquinona/análogos & derivados , Estabilidad de Medicamentos , Emulsiones/química , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Concentración Osmolar , Tamaño de la Partícula , Ubiquinona/química
14.
Chemosphere ; 242: 125244, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31896184

RESUMEN

Efficient wastewater restoration depends on the robustness and capability of the catalyst to promote sophisticated decontamination technologies. In this study, Co3Fe7-CoFe2O4 nanoparticles (NPs) prepared by facile pyrolysis were completely characterized and used to decompose 2,4-dichlorophenol (2,4-DCP). Furthermore, the catalytic performance and relevant mechanisms involved in the activation of peroxymonosulfate (PMS) were also investigated. The optimal conditions were achieved at the catalyst loading of 0.05 g L-1, PMS dosage of 1.26 g L-1, and pH of 7.7 through the response surface methodology by using the Box-Behnken design model. Under optimal conditions, 97.1% efficiency of 2,4-DCP removal was obtained within 30 min. Moreover, the quenching experiments and electron paramagnetic resonance result indicated that sulfate (SO4•-) and hydroxyl (HO•) radicals were considered as the dominant reactive oxygen species, which resulted in the effective removal of 2,4-DCP in the Co3Fe7-CoFe2O4/PMS system. Moreover, Co3Fe7-CoFe2O4 showed efficient catalytic performance in continuous five runs and exhibited less metal leaching of 0.052 and 0.036 mg L-1 for Co and Fe species, respectively. Furthermore, no considerable change was observed in the structural characteristics of the fresh and used Co3Fe7-CoFe2O4 catalytic system. The above-mentioned results indicated that the synergistic effects between Co3Fe7 alloy and CoFe2O4 spinel not only significantly improved the activity and long-term durability of the catalyst, but also accelerated the Co3+/Co2+ and Fe3+/Fe2+ redox cycles. Overall, the Co3Fe7-CoFe2O4/PMS system provides a novel advanced oxidation approach to further develop multifunctional transition metal-based nanomaterials responsible for producing surface-bound radicals and enhancing the remediation of refractory pollutants in the environmental application.


Asunto(s)
Óxido de Aluminio/química , Clorofenoles/química , Óxido de Magnesio/química , Peróxidos/química , Eliminación de Residuos Líquidos/métodos , Aleaciones , Catálisis , Nanopartículas/química , Oxidación-Reducción , Fenoles , Aguas Residuales
15.
J Agric Food Chem ; 68(4): 1051-1063, 2020 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-31910005

RESUMEN

Glycyrrhizic acid (GA) and GA nanofibrils (GN) have been shown to be efficient natural emulsifiers for formation and stabilization of food emulsions. In this work, the emulsion properties of GN in the presence of soy protein isolate-pectin complex nanoparticles (SPNPs) were studied to understand the impact of the nanofibril-nanoparticle interactions on emulsion stabilization. In the presence of low GN concentrations (0.1-0.5 wt %), the synergy in reducing the interfacial tension was observed due to SPNPs-GN complexation in the bulk and at the interface by hydrogen bonding, endowing the prepared emulsions with an overall smaller droplet size. However, obvious flocculation and clustering of oil droplets occurred in these emulsions (especially at 0.25 and 0.5 wt % GN), which are probably induced by a depletion mechanism. At high GN concentrations (1-2 wt %), due to the preferential adsorption, the GN mainly dominated the interface and the subsequent formation and properties of emulsions. Accordingly, the self-standing emulsion gels were obtained, showing a small droplet size with d32 of about 1.0-1.5 µm, homogeneous appearance and microstructure, and encouraging rheological properties including high gel strength, shear sensitivity, and good thixotropic recovery. This is mainly attributed to the formation of a fibrillar hydrogel network in the continuous phase as well as around the droplet surfaces.


Asunto(s)
Ácido Glicirrínico/química , Nanofibras/química , Nanopartículas/química , Pectinas/química , Proteínas de Soja/química , Adsorción , Emulsiones/química , Geles/química , Tamaño de la Partícula
16.
Anal Bioanal Chem ; 412(1): 81-91, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31953713

RESUMEN

Methods for detecting mycotoxins are very important because of the great health hazards of mycotoxins. However, there is a high background and low signal-to-noise ratio in real-time sensing, and therefore it is difficult to meet the fast, accurate, and convenient requirements for control of food quality. Here we constructed a quantitative fluorescence image analysis based on multicolor upconversion nanocrystal (UCN)-encoded microspheres for detection of ochratoxin A and zearalenone. The background-free encoding image signal of UCN-doped microspheres was captured by fluorescence microscopy under near-infrared excitation, whereas the detection image signal of phycoerythrin-labeled secondary antibodies conjugated to the microspheres was captured under blue light excitation. We custom-wrote an algorithm to analyze the two images for the same sample in 10 s, and only the gray value in the red channel of the secondary probe confirmed the quantity. The results showed that this novel detection platform performed feasible and reliable fluorescence image measurements by this method. Additionally, the limit of detection of was 0.34721 ng/mL for ochratoxin A and 0.41162 ng/mL for zearalenone. We envision that this UCN encoding strategy will be usefully applied for fast, accurate, and convenient testing of multiple food contaminants to ensure the safety of the food.


Asunto(s)
Microesferas , Ocratoxinas/análisis , Zearalenona/análisis , Contaminación de Alimentos/análisis , Inmunoensayo/métodos , Límite de Detección , Nanopartículas/química , Relación Señal-Ruido
17.
Anal Bioanal Chem ; 412(4): 871-880, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31901958

RESUMEN

Novel carbon dots (CDs) were synthesized by a one-pot hydrothermal approach using ampicillin as a precursor, and the as-prepared CDs exhibited a high quantum yield (23%). The CDs were found to possess abundant surface functional groups, thus providing good permeability to the cell, and the antibacterial activity of CDs was evaluated. S. aureus and L. monocytogenes were selected as model bacteria, and our results showed that the CDs exhibited antibacterial activity against S. aureus and L. monocytogenes under visible light illumination, even at low concentrations. The antibacterial mechanism is believed to be the production of reactive oxygen species (ROS) from CDs under visible light irradiation, which attacked the bacterial cell membranes, resulting in the death of the bacteria. In addition, because of the multicolor fluorescence properties of CDs, staining of S. aureus and L. monocytogenes obtained multicolor fluorescence images at different excitation wavelengths. Based on these results, CDs are a promising candidate material for biological applications. Graphical abstract.


Asunto(s)
Ampicilina/farmacología , Antibacterianos/farmacología , Carbono/farmacología , Listeria monocytogenes/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Ampicilina/análogos & derivados , Ampicilina/síntesis química , Antibacterianos/síntesis química , Antibacterianos/química , Carbono/química , Humanos , Listeriosis/tratamiento farmacológico , Nanopartículas/química , Infecciones Estafilocócicas/tratamiento farmacológico
18.
Artículo en Inglés | MEDLINE | ID: mdl-31990642

RESUMEN

Titanium dioxide is a white colourant authorised as food additive E171 in the EU and is applied in a range of food products. Currently the EU specifications for E171 do not refer to the characterisation of particle size distribution; however, this may be requested in the near future. Only a few studies have been published to date reporting data on the size distribution of food grade titanium dioxide. The aim of this study was to characterise the size distribution of titanium dioxide particles contained in eight confectionery products and the pristine titanium dioxide samples used in each of the products. This allowed the direct comparison of the particle size distribution in both the pristine and the extracted materials. By using various analytical techniques, such as transmission electron microscopy, single particle inductively coupled plasma mass spectrometry (sp-ICPMS) and centrifuge liquid sedimentation (CLS) for the characterisation and quantification of the titanium dioxide particle sizes, the impact of the instrumentation on the results was systematically studied. The volume-specific surface area (VSSA) and crystalline structure were also determined for all additives.


Asunto(s)
Aditivos Alimentarios/química , Nanopartículas/química , Titanio/química , Cristalización , Análisis de los Alimentos/métodos , Tamaño de la Partícula , Propiedades de Superficie
19.
J Photochem Photobiol B ; 204: 111781, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31981989

RESUMEN

In the recent years, copper tungstate (CuWO4) has been widely researched for its photocatalytic properties as it responds in the visible light range to augment the utilization of solar energy. In the present report, CuWO4 was synthesized through a facile and cost-effective solvothermal method, followed by annealing process at 700∘C. The structural, morphological, compositional and optical property of the synthesized powders were examined by X-ray diffraction, scanning electron microscope, UV-visible, Raman and photoluminescence studies. The photocatalytic activity of the nanostructured CuWO4 was evaluated by the degradation of methylene blue (MB) and methyl orange (MO) in aqueous solution under one sun light irradiation. The degradation efficiency of MB was found to be about 70% while that of MO was only 57% at 240 min in the same irradiation time. Surprisingly, the degradation process was accelerated by the addition of electron capturing agent H2O2 and thus MB dye was completely degraded within the time interval of 30 min while MO degraded in 75 min. These results prove that CuWO4 nanoparticles possess significant photocatalytic activity towards MO and MB dyes, thus indicating the feasibility of using CuWO4 for the active treatment of organic contaminants in the industrial effluents.


Asunto(s)
Compuestos Azo/química , Peróxido de Hidrógeno/química , Azul de Metileno/química , Luz Solar , Compuestos de Tungsteno/química , Catálisis , Cobre/química , Nanopartículas/química , Oxidación-Reducción , Fotólisis/efectos de la radiación
20.
Pharm Res ; 37(3): 40, 2020 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-31970499

RESUMEN

PURPOSES: Senescence is an inevitable and irreversible process, which may lead to loss in muscle and bone density, decline in brain volume and loss in renal clearance. Although aging is a well-known process, few studies on the consumption of nanodrugs by elderly people were performed. METHODS: We evaluated three different nanosystems: i) carbon based nanosystem (Graphene Quantum Dots, GQD), ii) polymeric nanoparticles and mesoporous silica (magnetic core mesoporous silica, MMSN). In previous studies, our group has already characterized GQD and MMSN nanoparticles by dynamic light scattering analysis, atomic force microscopy, transmission electron microscopy, X-ray diffraction, Raman analysis, fluorescence and absorbance. The polymeric nanoparticle has been characterized by AFM and DLS. All the nanosystems were radiolabeled with 99 m-Tc by. The in vivo biodistribution/tissue deposition analysis evaluation was done using elder (PN270) and young (PN90) mice injected with radioactive nanosystems. RESULTS: The nanosystems used in this study were well-formed as the radiolabeling processes were stable. Biodistribution analysis showed that there is a decrease in the uptake of the nanoparticles in elder mice when compared to young mice, showing that is necessary to increase the initial dose in elder people to achieve the same concentration when compared to young animals. CONCLUSION: The discrepancy on tissue distribution of nanosystems between young and elder individuals must be monitored, as the therapeutic effect will be different in the groups. Noteworthy, this data is an alarm that some specific conditions must be evaluated before commercialization of nano-drugs. Graphical Abstract Changes between younger and elderly individuals are undoubtedly, especially in drug tissue deposition, biodistribution and pharmacokinetics. The same thought should be applied to nanoparticles. A comprehensive analysis on how age discrepancy change the biological behavior of nanoparticles has been performed.


Asunto(s)
Grafito/química , Nanopartículas/química , Nanopartículas/metabolismo , Poliésteres/química , Dióxido de Silicio/química , Factores de Edad , Animales , Marcaje Isotópico , Nanopartículas de Magnetita/química , Ratones , Modelos Animales , Nanopartículas/administración & dosificación , Tamaño de la Partícula , Porosidad , Propiedades de Superficie , Tecnecio/química , Distribución Tisular
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