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1.
Chem Commun (Camb) ; 55(66): 9833-9836, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31363722

RESUMO

Herein, through using electropolymerized pyrrole (PPy) to coat near-infrared upconversion nanoparticles (UCNPs) on an indium tin oxide (ITO) electrode, the as-prepared PPy/UCNPs photoelectrode could generate an interfacial electric field, release rare earth ions and induce reactive oxygen species (ROS) in PC12 cells under NIR irradiation, which could realize wireless neurite development and outgrowth.


Assuntos
Estimulação Elétrica , Crescimento Neuronal , Tecnologia sem Fio , Animais , Raios Infravermelhos , Células PC12 , Polimerização , Pirróis/química , Ratos , Espectrofotometria Ultravioleta
2.
Chem Commun (Camb) ; 55(66): 9829-9832, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31363730

RESUMO

Polyethylene glycol grafted pyrrole-based conjugated polymers are synthesized through a one-pot multicomponent methodology, the self-assemblies of which enable nanoparticle size-selective encapsulation of drug molecules and their sustained release. Efficient loading of curcumin through drug-nanoparticle core interactions is probed using FRET, and the inherently fluorescent nature of polypyrrole could be used to detect these nanocarriers intracellularly.


Assuntos
Portadores de Fármacos , Nanopartículas/química , Polietilenoglicóis/química , Polímeros/química , Pirróis/química , Linhagem Celular Tumoral , Curcumina/administração & dosagem , Transferência Ressonante de Energia de Fluorescência , Humanos , Interações Hidrofóbicas e Hidrofílicas , Concentração Inibidora 50 , Microscopia Eletrônica de Transmissão , Espectrofotometria Ultravioleta
3.
Int J Nanomedicine ; 14: 4667-4679, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31308652

RESUMO

Purpose: The pathogenicity in Candida spp was attributed by several virulence factors such as production of tissue damaging extracellular enzymes, germ tube formation, hyphal morphogenesis and establishment of drug resistant biofilm. The objective of present study was to investigate the effects of silver nanoparticles (AgNPs) on growth, cell morphology and key virulence attributes of Candida species. Methods: AgNPs were synthesized by the using seed extract of Syzygium cumini (Sc), and were characterized by UV-Vis spectrophotometer, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscopy (TEM). ScAgNPs were used to evaluate their antifungal and antibacterial activity as well as their potent inhibitory effects on germ tube and biofilm formation and extracellular enzymes viz. phospholipases, proteinases, lipases and hemolysin secreted by Candida spp. Results: The MICs values of ScAgNPs were ranged from 0.125-0.250 mg/ml, whereas the MBCs and MFCs were 0.250 and 0.500 mg/ml, respectively. ScAgNPs significantly inhibit the production of phospholipases by 82.2, 75.7, 78.7, 62.5, and 65.8%; proteinases by 82.0, 72.0, 77.5, 67.0, and 83.7%; lipase by 69.4, 58.8, 60.0, 42.9, and 65.0%; and hemolysin by 62.8, 69.7, 67.2, 73.1, and 70.2% in C. albicans, C. tropicalis, C. dubliniensis, C. parapsilosis and C. krusei, respectively, at 500 µg/ml. ScAgNPs inhibit germ tube formation in C. albicans up to 97.1% at 0.25 mg/ml. LIVE/DEAD staining results showed that ScAgNPs almost completely inhibit biofilm formation in C. albicans. TEM analysis shows that ScAgNPs not only anchored onto the cell surface but also penetrated and accumulated in the cytoplasm that causes severe damage to the cell wall and cytoplasmic membrane. Conclusion: To summarize, the biosynthesized ScAgNPs strongly suppressed the multiplication, germ tube and biofilm formation and most importantly secretion of hydrolytic enzymes (viz. phospholipases, proteinases, lipases and hemolysin) by Candia spp. The present research work open several avenues of further study, such as to explore the molecular mechanism of inhibition of germ tubes and biofilm formation and suppression of production of various hydrolytic enzymes by Candida spp.


Assuntos
Antifúngicos/farmacologia , Candida/crescimento & desenvolvimento , Candida/patogenicidade , Nanopartículas Metálicas/química , Prata/farmacologia , Antifúngicos/química , Biofilmes/efeitos dos fármacos , Candida/citologia , Candida/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Proteínas Hemolisinas/metabolismo , Humanos , Hidrólise , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Syzygium/química , Virulência/efeitos dos fármacos , Fatores de Virulência
4.
Chem Commun (Camb) ; 55(66): 9769-9772, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31329196

RESUMO

We report the accelerated photoisomerization of amphiphilic lophine dimers based on the inner environments of molecular assemblies and rapid control of the interfacial properties of aqueous solution with photoirradiation. This novel photoisomerization system enables on-demand controlled release of drugs, perfumes, and other active compounds.


Assuntos
Imidazóis/química , Dimerização , Sistemas de Liberação de Medicamentos , Isomerismo , Processos Fotoquímicos , Espectrofotometria Ultravioleta , Tensão Superficial
5.
Food Chem ; 298: 125086, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31272050

RESUMO

Methylglyoxal (MGO) is a highly reactive ɑ-dicarbonyl compound that may adversely impact food quality and human health by modifying proteins. The kinetics of the reaction of naringenin with MGO was studied at pH 6-8 and 37 °C by UV-Vis spectrophotometry and reaction products were characterized by liquid chromatography-mass spectrometry (LC-MS/MS). The apparent second order rate constant (k2) increased at pH above the lowest pKa value of naringenin, indicating deprotonated naringenin as the main reactant. A Lederer-Manasse type reaction mechanism is suggested, with dehydration of the MGO-dihydrate as a rate determining step. The quantitative data obtained in the present study was used to simulate the competitive reaction between MGO and nucleophilic amino acid residues (Lys, Arg and Cys) and naringenin in milk. It is predicted that naringenin will be able to efficiently trap MGO during storage of milk, although the reversible trapping of MGO by Cys residues is initially kinetically favourable.


Assuntos
Flavanonas/química , Aldeído Pirúvico/química , Aminoácidos/química , Cromatografia Líquida , Concentração de Íons de Hidrogênio , Cinética , Proteínas do Leite/química , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Ultravioleta , Espectrometria de Massas em Tandem
6.
Int J Nanomedicine ; 14: 4017-4028, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239667

RESUMO

Background: The design of novel nanoparticles with higher therapeutic efficacy and lower side effects, is still difficult but encouraging in cancer therapy. Specifically, for upconversion nanoparticles (UCNP)-based drug release, a high intensity of NIR light (1.4~5.0 W/cm2) above the maximum permissible exposure (0.33 W/cm2 for 980 nm) is commonly used and severely limits its practical application. Methods: The highly emissive UCNP is first synthesized and then coated with mesoporous silica (MS) shell (UCMS). Next, the surface of UCMS is modified with the thioether (-S-BP) linker, leading to UCMS-S-BP nanoparticles. Finally, after the drug doxorubicin (Dox) is loaded into the pore channels of UCMS, the pore openings are blocked by the ß-cyclodextrin (ß-CD) gatekeeper through the association with the -S-BP linker (UCMS(Dox)-S-BP@ß-CD). Results: Upon 980 nm NIR light irradiation with an ultralow intensity of 0.30 W/cm2, it is found that the loaded Dox can be released through the cleavage of thioether linkers triggering dissociation of ß-CD gatekeepers. The in vitro results exhibited significantly therapeutic efficacy with 85.2% of HeLa cells killed in this study. Conclusions: An ultralow-intensity NIR light triggered on-demand drug release system has been developed by employing highly emissive UCNP and photocleavable linker with low bond dissociation energy to avoid the potential photodamage on healthy neighbor cells.


Assuntos
Liberação Controlada de Fármacos , Raios Infravermelhos , Nanopartículas/química , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Teoria da Densidade Funcional , Doxorrubicina/farmacologia , Endocitose/efeitos dos fármacos , Fluorescência , Células HeLa , Humanos , Nanopartículas/ultraestrutura , Espectrofotometria Ultravioleta , Termodinâmica
7.
Anal Bioanal Chem ; 411(21): 5563-5576, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31209547

RESUMO

The Surface-enhanced Raman spectroscopy (SERS) method based on gold nanoparticles as SERS substrate was investigated for the label-free detection and quantification of probiotic bacteria that are widely used in various pharmaceutical formulations. Indeed, the development of a simple and fast SERS method dedicated to the quantification of bacteria should be very useful for the characterization of such formulations in a more convenient way than the usually performed tedious and time-consuming conventional counting method. For this purpose, uncoated near-spherical gold nanoparticles were developed at room temperature by acidic treatment of star-like gold nanoparticle precursors. In this study, we first investigated the influence of acidic treatment conditions on both the nanoparticle physicochemical properties and SERS efficiency using Rhodamine 6G (R6G) as "model" analyte. Results highlighted that an effective R6G Raman signal enhancement was obtained by promoting chemical effect through R6G-anion interactions and by obtaining a suitable aggregation state of the nanoparticles. Depending on the nanoparticle synthesis conditions, R6G SERS signals were up to 102-103-fold greater than those obtained with star-like gold nanoparticles. The synthesized spherical gold nanoparticles were then successfully applied for the detection and quantification of Lactobacillus rhamnosus GG (LGG). In that case, the signal enhancement was especially due to the combination of anion-induced chemical enhancement and nanoparticle aggregation on LGG cell wall consecutive to non-specific interactions. Both the simplicity and speed of the procedure, achieved under 30 min, including nanoparticle synthesis, sample preparation, and acquisition of SERS spectra, appeared as very relevant for the characterization of pharmaceutical formulations incorporating probiotics. Graphical abstract.


Assuntos
Ouro/química , Lactobacillus rhamnosus/isolamento & purificação , Nanopartículas Metálicas/química , Análise Espectral Raman/métodos , Probióticos , Rodaminas/química , Espectrofotometria Ultravioleta
8.
Food Chem ; 293: 112-119, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151590

RESUMO

A fast and simple method, which employs QuEChERS and HPLC-UV, was developed to determine preservatives in processed foods from different classes. The method showed correlation coefficients above 0.99, LOQs between 0.13 and 0.33 mg kg-1 and recoveries between 91 and 107%, with RSD ≤ 5.3%. Levels of preservatives were up to 2040 mg kg-1 for benzoates, up to 3185 mg kg-1 for sorbates and up to 452 mg kg-1 for methylparaben. Only four out of 82 samples under analysis were above the maximum level allowed by the legislation. Additionally, daily intakes of preservatives were estimated. Regarding benzoates, relatively high intakes were estimated (25% of the acceptable daily intake - ADI) in comparison with sorbates (5% of ADI) and parabens (<1% of ADI), when mean consumption is considered. This method is a good alternative to determining preservatives in different food samples.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Conservantes de Alimentos/análise , Benzoatos/análise , Cromatografia Líquida de Alta Pressão/normas , Análise de Alimentos , Limite de Detecção , Nível de Efeito Adverso não Observado , Parabenos/análise , Controle de Qualidade , Ácido Sórbico/análise , Espectrofotometria Ultravioleta , Inquéritos e Questionários
9.
Anal Bioanal Chem ; 411(20): 5023-5031, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31177332

RESUMO

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


Assuntos
Cosméticos/química , Sucos de Frutas e Vegetais/análise , Líquidos Iônicos/química , Microextração em Fase Líquida/métodos , Nanopartículas Metálicas/análise , Prata/química , Artefatos , Estudos de Viabilidade , Limite de Detecção , Nanopartículas Metálicas/química , Espectrofotometria Ultravioleta/métodos , Ressonância de Plasmônio de Superfície
10.
Anal Bioanal Chem ; 411(20): 5175-5186, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31187200

RESUMO

An ultrasensitive electrochemiluminescence (ECL) immunosensor for alpha-fetoprotein (AFP) detection based on a poly(aniline-luminol)/graphene oxide nanocomposite was developed. The nanocomposite, which was prepared using a fast and simple chemical oxidation strategy for the first time, showed excellent ECL performance. This outstanding ECL performance is due to the formation of poly(aniline-luminol) on the graphene oxide (GO) surface and the excellent electron-transfer properties of GO. Moreover, the poly(aniline-luminol)/graphene oxide nanocomposite has abundant amino groups at its surface, making it a good platform for biomacromolecule labeling. Using the nanocomposite, a novel ECL immunosensor for the determination of AFP was successfully developed. Anti-AFP was immobilized on the surface of a poly(aniline-luminol)/graphene oxide nanocomposite-modified electrode using a glutaraldehyde crosslinking method to form the ECL immunosensor. The AFP was then captured at the modified electrode surface through an antigen-antibody immunoreaction. When the AFP was captured by its antibody, the ECL intensity decreased. This ECL immunosensor for the detection of AFP exhibited a linear range of 1.7 × 10-12 to 1.7 × 10-8 mg mL-1 and a detection limit of 5 × 10-13 mg mL-1, indicating high sensitivity and linearity across a wide concentration range. Furthermore, the immunosensor was successfully applied to determine AFP in a real-world human serum sample. Graphical abstract A new poly(aniline-luminol)/graphene oxide nanocomposite was prepared using a fast and simple strategy for the first time, and an ultrasensitive electrochemiluminescence (ECL) immunosensor for alpha-fetoprotein (AFP) detection based on this nanocomposite was developed.


Assuntos
Compostos de Anilina/química , Técnicas Biossensoriais , Técnicas Eletroquímicas/métodos , Grafite/química , Luminescência , Luminol/química , Nanocompostos/química , alfa-Fetoproteínas/análise , Humanos , Limite de Detecção , Microscopia Eletrônica de Transmissão , Reprodutibilidade dos Testes , Soro , Espectrofotometria Ultravioleta , Análise Espectral Raman , alfa-Fetoproteínas/imunologia
11.
Anal Bioanal Chem ; 411(20): 5287-5296, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31201461

RESUMO

Singlet oxygen (1O2) is the focus of study in many fields, including phototoxicity, antioxidant activity, pollutant weathering, photodynamic therapy, and water disinfection. The imidazole plus RNO (Imd/RNO) method, originated by Kraljic and El Mohsni, is commonly used to monitor singlet oxygen production. In this method, 1O2 is quenched by an acceptor, imidazole (Imd), during the formation of a trans-annular peroxide intermediate that bleaches the sensor, p-nitrosodimethylaniline (RNO). Though the method has been widely used, including to monitor 1O2 production in complex environments, such as surfactants and cells, studies reporting the efficiency of the assay in complex solvents have not been reported. In this research, the Imd/RNO method in complex, biorelevant solvents, i.e., sodium dodecyl sulfate, octanol, and phosphate buffer-saturated octanol, was compared with reference solvents, i.e., phosphate buffer, ethanol, and methanol, for monitoring 1O2 produced by Rose Bengal photosensitization using time-resolved, broadband UV-Vis absorbance measurements. Rates of sensor bleaching and sensitizer photodegradation were simultaneously monitored in each solvent to investigate correlations between the disappearance rates of sensor and sensitizer. The quantum yields of 1O2 production (ϕ∆) in each solvent were calculated using a relative actinometric method. The dependence of sensor bleaching and sensitizer degradation on acceptor concentration and solvent polarity, and the results of assay controls suggest mechanistic differences underlying the reactions comprising the Imd/RNO method. These results demonstrate the need for caution and controls when using the method in complex samples including those containing cells, tissues, or nanoscale particles.


Assuntos
Imidazóis/química , Compostos Nitrosos/química , Oxigênio Singlete/análise , Solventes/química , Fármacos Fotossensibilizantes/química , Rosa Bengala/química , Espectrofotometria Ultravioleta
12.
Food Chem ; 293: 66-73, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151650

RESUMO

A simple biologically active phenolic methyl gallate (MeG) was used as a model compound to identify the nature of the complexes it formed with Al3+, Fe3+, Cu2+, and Sn2+ as analyzed by ultraviolet (UV) spectroscopic and computational methods. The results showed that, among all the metal ions studied in the present study, MeG has the highest formation constant with Al3+, and the complexation between MeG and metal ions is a pH-dependent reaction. At pH 6.0, complexes with a stoichiometry of 1:1 were formed with Al3+, Fe3+, and Sn2+, whereas 2:3 complexes were formed with Cu2+. Using a functional density quantum-chemical method, it was shown that the ligand involved in the complexation of MeG-Al undergoes significant changes in electronic delocalization. Modeling of electronic spectra with water as solvent shows high reproducibility for the experimental features of the complexes. The calculations confirm that chelation of Al3+ occurs at the double-deprotonated phenolic hydroxyls.


Assuntos
Ácido Gálico/análogos & derivados , Metais/química , Teoria da Densidade Funcional , Ácido Gálico/química , Concentração de Íons de Hidrogênio , Íons/química , Espectrofotometria Ultravioleta
13.
Plant Physiol Biochem ; 141: 407-414, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31228797

RESUMO

Polyphenols are constituents of all higher plants. However, their biosynthesis is often induced when plants are exposed to abiotic stresses, such as drought. The aim of the present work was to determine the phenolic status in the roots of olive trees grown under water deficit conditions. The results revealed that roots of water-stressed plants had a higher content of total phenols. The main compound detected in well-watered olive tree roots was verbascoside. Oleuropein was established as the predominant phenolic compound of water-stressed plants. The oleuropein/verbascoside ratio varied between 0.31 and 6.02 in well-watered and water-stressed plants respectively, which could be a useful indicator of drought tolerance in olive trees. Furthermore, this study is the first to provide experimental evidence showing that luteolin-7-rutinoside, luteolin-7-glucoside and apigenin-7-glucoside were the dominant flavonoid glucosides in olive tree roots and showed the most significant variations under water stress.


Assuntos
Secas , Iridoides/química , Olea/fisiologia , Raízes de Plantas/fisiologia , Antioxidantes/química , Apigenina/química , Flavonoides/química , Glucosídeos/química , Fenol/química , Fenóis/química , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/química , Extratos Vegetais/química , Folhas de Planta/fisiologia , Polifenóis/química , Espectrofotometria Ultravioleta , Estresse Fisiológico , Água
14.
Int J Nanomedicine ; 14: 3273-3282, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190793

RESUMO

Background: Biotemplates are attractive templates for the synthesis of nanometals and inorganic compound nanostructures. Methods: In this work, for the first time, iron oxide quantum dot nanoparticles (QDNPs) were prepared using albumen as a biotemplate. Next, the prepared nanoparticles were characterized using dynamic light scattering for determination and evaluation of the hydrodynamic diameter and zeta potential of the particles. Moreover, optical and scanning electron microscopes were applied to evaluate morphology. Spherically shaped iron oxide QDNPs were obtained with appropriate particle size and distribution. Fe(NO3)3.9H2O and egg whites were used as the source of the Fe element and particle size control agent in the aqueous medium, respectively. Afterward, the effect of calcination temperature parameters on the crystallinity purity and size of Fe nanocrystals were investigated. Also, products were characterized by various detection analyses such as thermogravimetry analysis/DTA, XRD, UV-vis, Fourier transform infrared (FT-IR,) transmission electron microscopy, and SEM. In order to investigate the antibacterial effect of the synthesized Fe nanobiological samples against bacterial strains, they were dissolved in dimethyl sulfoxide and diluted using distilled water. Then, different serial dilutions of 64 µg/mL, 32 µg/mL, 16 µg/mL, 8 µg/mL, 4 3BCg/mL, 2 µg/mL, 1 µg/mL, and 0.5 µg/mL of nanobiological samples were prepared and added to the Mueller-Hinton agar medium. Results: The minimum inhibitory concentration of the synthesized iron oxide quantum dot nanobiological was determined against pathogenic microbial strains of bacteria including Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Micrococcus luteus, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, and Klebsiella pneumonia on the culture medium plate. Conclusion: The present nanobiological samples can be considered as a new material candidate for antibacterial drugs.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Proteínas do Ovo/química , Compostos Férricos/química , Nanopartículas/química , Pontos Quânticos/química , Animais , Difusão Dinâmica da Luz , Camundongos , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Espectrofotometria Ultravioleta , Difração de Raios X
15.
Int J Nanomedicine ; 14: 3439-3454, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190802

RESUMO

Objective: The microbial, physico-chemical and optical corruptions threaten a variety of foods and drugs and consequently the human biological safety and its accessible resources. The humanbeing's tendency towards bio-based materials and natural plant-extracts led to an increase in the usage of antimicrobial biocomposites based on medicinal herbs. Miswak (Salvadora persica L.) extract (SPE) has been proved effective for its antimicrobial and other biological activities. Therefore, in this study, titanium dioxide (TiO2) nanoparticles (TONP) and SPE were applied to fabricate antimicrobial carboxymethyl cellulose (Na-CMC) based bio-nanocomposites which would simultaneously promote some thermo-physical and barrier properties. Methods: CMC-neat film (C1), CMC/TONP-2% (C2) and CMC/TONP-2% with 150, 300 and 450 mg/mL SPE (SPE150, SPE30 and SPE450, respectively) were fabricated. The physical and mechanical properties; elemental mapping analysis (MAP), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA-DTG); fourier transform infrared (FTIR), energy-dispersive X-ray (EDX) and UV-vis spectroscopies were done to further validate the results. Results: Addition of TONP (2%) improved the blocking of UV light at 280 nm while SPE-containing nanocomposites completely blocked it. FTIR, XRD and SEM confirmed the formation of homogeneous films and high miscibility of applied materials. TONP led to an increase in Young's modulus (YM) and stress at break (SB) while SPE decreased them and enhanced the elongation to break (EB) (flexibility) of the active nanocomposites. Compared to CMC-film, the thermo-gravimetric analysis (TGA-DTG) showed a higher thermal stability for CMC/TONP and CMC/TONP/SPE nanocomposites. The EDX spectroscopy and elemental mapping analysis (MAP) proved the existence and well-distributedness of Na, K, Cl, S, Ti, F and N elements in SPE-activated nanocomposites. The pure SPE and SPE-activated nanocomposites showed a favorable antimicrobial activity against both gram-positive (Staphylococcus aureus) and negative (Escherichia coli) bacteria. Conclusion: The CMC-TiO2-SPE nanocomposites were homogeneously produced. Combination of TiO2 nanoparticles and dose-dependent SPE led to an improvement of thermal stability, and high potential in antimicrobial and UV-barrier properties. These results can generally highlight the role of the fabricated antimicrobial bio-nanocomposites as a based for different applications especially in food/drug packaging or coating.


Assuntos
Antibacterianos/farmacologia , Nanocompostos/química , Nanopartículas/química , Extratos Vegetais/farmacologia , Salvadoraceae/química , Temperatura Ambiente , Titânio/química , Elementos , Humanos , Umidade , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Permeabilidade , Espectrofotometria Ultravioleta , Staphylococcus aureus/efeitos dos fármacos , Vapor , Termogravimetria , Difração de Raios X
16.
Int J Nanomedicine ; 14: 3533-3541, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190810

RESUMO

Background: Himalayan honey, a natural product of wild honey bees found in the Himalayan mountains of Nepal, has been used in medicine for many years. The successful development of nanotechnology and beneficial effects of honey would bring a new opportunity to synthesize hybrid nanomaterials for biomedical applications. Thus, the purpose of this study was to load Himalayan honey onto iron oxide nanoparticles (IO-NPs) and study their antioxidant and antimicrobial activities. Methods: Himalayan honey loaded iron oxide nanoparticles (HHLIO-NPs) were synthesized and X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses were performed for characterization. UV-VIS spectra confirmed the loading of honey onto nanoparticles. The antioxidant activity of these nanoparticles was studied against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical system. We also tested antimicrobial activity of HHLIO-NPs using well diffusion method towards both Gram-positive and Gram-negative bacterial strains of Staphylococus aureus & Escherichia coli. Results: From XRD analysis, the average particle size was found to be 33-40 nm. The SEM images show needle shape porous structures of HHLIO-NPs compared to free IO-NPs indicating the surfactant-like behaviour of honey. In DPPH radical system, the scavenging activities of Himalayan honey (HH), free IO-NPs and HHLIO-NPs ranged 7.93-35.99%, 11.02-52.02% and 16.10-80.52% respectively, with corresponding IC50 values of 1.36 mg/mL, 1.09 mg/mL and 0.52 mg/mL. The antimicrobial property of all test samples showed a noteworthy inhibition on both bacterial strains. However, the HH and HHLIO-NPs exhibited strong antibacterial activity against E. coli. Conclusion: This work reveals that the biological activity of HH is enhanced significantly after loading into IO-NPs. Thus, the HHLIO-NPs would be a promising alternative for antioxidant and antimicrobial agents.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Compostos Férricos/química , Mel , Nanopartículas Metálicas/química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Concentração Inibidora 50 , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Espectrofotometria Ultravioleta , Staphylococcus aureus/efeitos dos fármacos , Difração de Raios X
17.
Int J Nanomedicine ; 14: 3543-3555, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190811

RESUMO

Background: In recent years, non-invasive imaging technologies for early cancer detection have drawn worldwide attention. In this study, an antinucleolin aptamer, AS1411, was successfully conjugated to BODIPY-labeled chitosan and studied on T47D and HEK-293 cell lines. Methods: After conjugation of the aptamer to chitosan nanoparticles and purification, its structure was confirmed using atomic force microscopy (AFM), electrophoretic light scattering (ELS) and dynamic light scattering (DLS). Results of AFM, DLS and ELS of both conjugation and chitosan were compared for confirmation of conjugation. Conjugates were mixed with BODIPY FL fluorescent dye, purified and lyophilized. The labeled conjugate was characterized using Fourier-transform infrared spectroscopy, ultraviolet-visible spectroscopy, ELS and DLS. In vitro cellular uptake and cytotoxic effects of BODIPY-labeled chitosan-AS1411 aptamer conjugates were evaluated using the XTT assay on T47D and HEK-293 cells and flow cytometry on T47D cells. Results: The data showed that uptake of BODIPY-labeled chitosan-AS1411 aptamer conjugate was satisfactory. Moreover, there was no statistically significant cytotoxicity of the conjugate on either cell line. Conclusion: The outcomes confirmed the potential application of this new targeted imaging agent as a novel cancer diagnostic agent for molecular imaging.


Assuntos
Compostos de Boro/química , Quitosana/química , Imagem Molecular/métodos , Nanopartículas/química , Oligodesoxirribonucleotídeos/química , Tamanho da Partícula , Aptâmeros de Nucleotídeos/química , Linhagem Celular Tumoral , Proliferação de Células , Endocitose , Fluorescência , Corantes Fluorescentes/química , Células HEK293 , Humanos , Microscopia de Força Atômica , Nanoconjugados/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática
18.
Int J Nanomedicine ; 14: 3691-3703, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190819

RESUMO

Background and aim: The extract of ginger, obtained from the rhizome of Zingiber officinale, contains 6-gingerol, 6-shogaol, 8-gingerol, and 10-gingerol. It has many therapeutic effects such as being chemopreventive against stroke and heart diseases, malabsorption, bacterial infections, indigestion, and nausea, which have been observed since ancient times. The main aim of this study is to evaluate the polyurethane (PU) as a proper material for the hollow nanoparticles' preparation. Methods: The PU nanoparticles were obtained by a spontaneous emulsification, in the presence of a nonionic surfactant, combined with an interfacial polyaddition process between an aliphatic diisocyanate and different mixtures of etheric and esteric polyols. The synthesis was done without any PU additives, such as catalysts, blowing agents, chains promoters, cross-linking agents, and stabilizers. Results: The particles present almost neutral pH values and low water solubility. They are heat resistant up to 280°C. Decreased irritation level was found in the assay of PU nanoparticles loaded with pure ginger extract (GE) on the murine skin tests than the irritation level recorded for pure GE. Conclusion: This research shows the reduced noxiousness of these PU nanoparticles and consequently the possibility of their use as a possible cardiovascular protector.


Assuntos
Cardiotônicos/farmacologia , Gengibre/química , Nanopartículas/química , Extratos Vegetais/farmacologia , Poliuretanos/química , Animais , Varredura Diferencial de Calorimetria , Eritema/patologia , Feminino , Concentração de Íons de Hidrogênio , Melaninas/metabolismo , Camundongos , Extratos Vegetais/química , Poliuretanos/síntese química , Solubilidade , Espectrofotometria Ultravioleta , Temperatura Ambiente
19.
Talanta ; 202: 531-539, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31171218

RESUMO

A specific version of the quartz crystal microbalance method has been proposed for quantitative evaluation of drug content in polymeric drug carrier systems. In this study, ammonio methacrylate copolymer (type B) microparticles and their standard solutions have been prepared and loaded with set amounts of the medications diltiazem (base) and lidocaine. The analytes have been segregatim deposited on the surface of the resonator and the drug content in them has been derived from the downshift of the resonance frequency produced by irreversible interaction of the drug molecules with irradiating hydrochloric gas. The obtained results have been statistically processed on a number of samples and have been found to exhibit excellent coherence to set theoretical values. As an alternative, the conventional pharmacopoeial UV-Vis spectral method has also been separately applied to studied samples, revealing worsened performance in the case of lidocaine due to polymer matrix interference. Thus the universality of the QCM method has been proved to add to its versatility and precision. The method appears to be readily applicable to the routine pharmaceutical quantity control of bulk and multiparticulate drug forms.


Assuntos
Resinas Acrílicas/química , Diltiazem/análise , Sistemas de Liberação de Medicamentos , Técnicas de Microbalança de Cristal de Quartzo , Estrutura Molecular , Espectrofotometria Ultravioleta , Propriedades de Superfície
20.
Food Chem ; 295: 387-394, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174773

RESUMO

Saffron is appreciated by its colour, taste, and aroma. To examine the effect of abiotic and biotic stress on these main properties, in the span of 2014-2016, saffron stigmas were collected from major different saffron cultivation areas of Iran and saffron quality was estimated. The quality of saffron was assessed by ultraviolet-visible spectroscopy following the ISO3632:2011 standard. However, the composition and concentration of crocetin esters, picrocrocin, safranal, and kaempferols, the most critical compounds determining the properties and quality of saffron can vary with the geographical origin and virus effects, being more accurate High-Performance Liquid Chromatography and Diode Array Detection (HPLC-DAD) methods were used to analyze saffron quality. Using HPLC-DAD we analyzed saffron plants grown at various conditions (considering altitude, temperature, and precipitation/rainfall) and in presence/absence of virus infections; we found that edaphoclimatic and cultivation conditions significantly determine the quality of the spice and the presence of virus modifies the content of its metabolites.


Assuntos
Crocus/química , Crocus/virologia , Análise de Alimentos/métodos , Doenças das Plantas/virologia , Altitude , Carotenoides/análise , Cromatografia Líquida de Alta Pressão , Crocus/metabolismo , Cicloexenos/análise , Qualidade dos Alimentos , Glucosídeos/análise , Irã (Geográfico) , Quempferóis/análise , Extratos Vegetais/química , Chuva , Metabolismo Secundário , Espectrofotometria Ultravioleta , Especiarias/análise , Terpenos/análise
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