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1.
Int J Mol Sci ; 22(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206928

RESUMO

Brush-like α-Fe2O3-ZnO heterostructures were synthesized through a sputtering ZnO seed-assisted hydrothermal growth method. The resulting heterostructures consisted of α-Fe2O3 rod templates and ZnO branched crystals with an average diameter of approximately 12 nm and length of 25 nm. The gas-sensing results demonstrated that the α-Fe2O3-ZnO heterostructure-based sensor exhibited excellent sensitivity, selectivity, and stability toward low-concentration NO2 gas at an optimal temperature of 300 °C. The α-Fe2O3-ZnO sensor, in particular, demonstrated substantially higher sensitivity compared with pristine α-Fe2O3, along with faster response and recovery speeds under similar test conditions. An appropriate material synergic effect accounts for the considerable enhancement in the NO2 gas-sensing performance of the α-Fe2O3-ZnO heterostructures.


Assuntos
Compostos Férricos/química , Nanoestruturas/química , Dióxido de Nitrogênio/análise , Óxido de Zinco/química , Técnicas de Química Analítica/métodos , Dióxido de Nitrogênio/química , Sensibilidade e Especificidade
2.
Int J Nanomedicine ; 16: 4431-4449, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34234435

RESUMO

Purpose: The present study deals with the in vitro evaluation of the potential use of coordination compound-based zinc oxide (ZnO) nanoparticles (NPs) for the treatment of triple negative breast cancer cells (TNBrCa). As BrCa is one of the most prevalent cancer types and TNBrCa treatment is difficult due to poor prognosis and a high metastasis rate, finding a more reliable treatment option should be of the utmost interest. Methods: Prepared by reacting zinc carboxylates (formate, acetate, propionate, butyrate, isobutyrate, valerate) and hexamethylenetetramine, 4 distinct coordination compounds were further subjected to two modes of conversion into ZnO NPs - ultrasonication with oleic acid or heating of pure precursors in an air atmosphere. After detailed characterization, the resulting ZnO NPs were subjected to in vitro testing of cytotoxicity toward TNBrCa and normal breast epithelial cells. Further, their biocompatibility was evaluated. Results: The resulting ZnO NPs provide distinct morphological features, size, biocompatibility, and selective cytotoxicity toward TNBrCa cells. They internalize into two types of TNBrCa cells and imbalance their redox homeostasis, influencing their metabolism, morphology, and ultimately leading to their death via apoptosis or necrosis. Conclusion: The crucial properties of ZnO NPs seem to be their morphology, size, and zinc content. The ZnO NPs with the most preferential values of all three properties show great promise for a future potential use in the therapy of TNBrCa.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Nanopartículas/química , Neoplasias de Mama Triplo Negativas/patologia , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos
3.
Molecules ; 26(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202852

RESUMO

Nano-based particles synthesized via green routes have a particular structure that is useful in biomedical applications as they provide cheap, eco-friendly, and non-toxic nanoparticles. In the present study, we reported the effect of various concentrations of Zinc oxide nanoparticles synthesized using A. lebbeck stem bark extract (ZnO NPsAL) as stabilizing agent on rat biochemical profiles and tissue morphology. Adult Wistar rats weighing 170 ± 5 g were randomly classified into eight groups of five rats each; Group A served as a control fed with normal diet and water. Groups B1, B2, C1, C2, D1, D2, and E were treated with 40 mg/kg and 80 mg/kg of the 0.01, 0.05, and 0.1 M biosynthesized ZnO NPsAL and zinc nitrate daily by the gavage method, respectively. The rats were anesthetized 24 h after the last treatment, blood samples, kidney, heart, and liver tissues were collected for biochemical and histopathological analysis. The rats mean body weight, serum alkaline phosphatase, alanine aminotransferase, creatinine, urea, bilirubin, protein, albumin, globulin, total cholesterol, triacylglycerol, and high-density lipoprotein were significantly altered with an increased concentration of biosynthesized ZnO NPsAL when compared with the control group (p < 0.05; n ≥ 5). Furthermore, histopathological analysis of treated rats' kidney, heart, and liver tissue revealed vascular congestion, tubular necrosis, inflammation, and cytoplasmic vacuolation. Biosynthesized ZnO NPsAL showed significant alteration in biochemical parameters and tissue morphology in rats with increasing concentrations of the nanoparticles.


Assuntos
Albizzia/química , Nanopartículas , Casca de Planta/química , Extratos Vegetais/química , Óxido de Zinco , Animais , Masculino , Nanopartículas/administração & dosagem , Nanopartículas/química , Nanopartículas/uso terapêutico , Especificidade de Órgãos , Ratos , Ratos Wistar , Óxido de Zinco/efeitos adversos , Óxido de Zinco/química , Óxido de Zinco/farmacologia
4.
Int J Mol Sci ; 22(10)2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34065496

RESUMO

The most critical group of all includes multidrug resistant bacteria that pose a particular threat in hospitals, as they can cause severe and often deadly infections. Modern medicine still faces the difficult task of developing new agents for the effective control of bacterial-based diseases. The targeted administration of nanoparticles can enhance the efficiency of conventional pharmaceutical agents. However, the interpretation of interfaces' interactions between nanoparticles and biological systems still remains a challenge for researchers. In fact, the current research presents a strategy for using ZnO NPs immobilization with ampicillin and tetracycline. Firstly, the study provides the mechanism of the ampicillin and tetracycline binding on the surface of ZnO NPs. Secondly, it examines the effect of non-immobilized ZnO NPs, immobilized with ampicillin (ZnONPs/AMP) and tetracycline (ZnONPs/TET), on the cells' metabolism and morphology, based on the protein and lipid profiles. A sorption kinetics study showed that the antibiotics binding on the surface of ZnONPs depend on their structure. The efficiency of the process was definitely higher in the case of ampicillin. In addition, flow cytometry results showed that immobilized nanoparticles present a different mechanism of action. Moreover, according to the MALDI approach, the antibacterial activity mechanism of the investigated ZnO complexes is mainly based on the destruction of cell membrane integrity by lipids and proteins, which is necessary for proper cell function. Additionally, it was noticed that some of the identified changes indicate the activation of defense mechanisms by cells, leading to a decrease in the permeability of a cell's external barriers or the synthesis of repair proteins.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Nanopartículas Metálicas/química , Nanocompostos/química , Zinco/química , Testes de Sensibilidade Microbiana/métodos , Óxido de Zinco/química
5.
Int J Mol Sci ; 22(11)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34071337

RESUMO

Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8-10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites.


Assuntos
Antibacterianos/química , Arecaceae/química , Celulose/química , Nanocompostos/química , Nanofibras/química , Óxido de Zinco/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Microscopia Eletrônica , Nanocompostos/ultraestrutura , Nanofibras/ultraestrutura , Tamanho da Partícula , Borracha/química , Salmonella/efeitos dos fármacos , Salmonella/crescimento & desenvolvimento , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Difração de Raios X
6.
Int J Mol Sci ; 22(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34069756

RESUMO

Hybrid nanostructures can be developed with inorganic nanoparticles (NPs) such as zinc oxide (ZnO) and natural antibacterials. ZnO NPs can also exert antibacterial effects, and we used them here to examine their dual action in combination with a natural antibacterial agent, protocatechuic acid (PCA). To produce hybrid nanoformulations, we functionalized ZnO NPs with four types of silane organic molecules and successfully linked them to PCA. Physicochemical assessment confirmed PCA content up to ~18% in hybrid nanoformulations, with a PCA entrapment efficiency of ~72%, indicating successful connection. We then investigated the in vitro release kinetics and antibacterial effects of the hybrid against Staphylococcus aureus. PCA release from hybrid nanoformulations varied with silane surface modification. Within 98 h, only 8% of the total encapsulated PCA was released, suggesting sustained long-term release. We used nanoformulation solutions collected at days 3, 5, and 7 by disc diffusion or log reduction to evaluate their antibacterial effect against S. aureus. The hybrid nanoformulation showed efficient antibacterial and bactericidal effects that also depended on the surface modification and at a lower minimum inhibition concentration compared with the separate components. A hybrid nanoformulation of the PCA prodrug and ZnO NPs offers effective sustained-release inhibition of S. aureus growth.


Assuntos
Hidroxibenzoatos/administração & dosagem , Hidroxibenzoatos/farmacologia , Óxido de Zinco/farmacologia , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Preparações de Ação Retardada/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Escherichia coli/efeitos dos fármacos , Infecções por Escherichia coli/tratamento farmacológico , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Nanopartículas/química , Nanopartículas/metabolismo , Nanoestruturas/química , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Óxido de Zinco/química , Óxido de Zinco/metabolismo
7.
Int J Nanomedicine ; 16: 3541-3554, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34079247

RESUMO

Purpose: Nanomaterials for antimicrobial applications have gained interest in recent years due to the increasing bacteria resistance to conventional antibiotics. Wound sterilization, water treatment and surface decontamination all avail from multifunctional materials that also possess excellent antibacterial properties, eg zinc oxide (ZnO). Here, we assess and compare the effects of synthesized hedgehog-like ZnO structures and commercial ZnO particles with and without mixing on the inactivation of bacteria on surfaces and in liquid environments. Methods: Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria in microbial culture medium were added to reverse spin bioreactors that contained different concentrations of each ZnO type to enable dynamic mixing of the bacteria-ZnO suspensions. Optical density of the bacteria-ZnO suspensions was measured in real-time and the number of viable bacteria after 24 h exposure was determined using standard microbiological techniques. The concentration of zinc ion generated from ZnO dissolution in different liquid types was estimated from the dynamic interaction exposure. Static antibacterial tests without agitation in liquid media and on agar surface were performed for comparison. Results: A correlation between increasing ZnO particle concentration and reduction in viable bacteria was not monotonous. The lowest concentration tested (10 µg/mL) even stimulated bacteria growth. The hedgehog ZnO was significantly more antibacterial than commercial ZnO particles at higher concentrations (up to 1000 µg/mL tested), more against E. coli than S. aureus. Minimum inhibitory concentration in microwell plates was correlated with those results. No inhibition was detected for any ZnO type deposited on agar surface. Zinc ion release was greatly suppressed in cultivation media. Scanning electron microscopy images revealed that ZnO needles can pierce membrane of bacteria whereas the commercial ZnO nanoparticles rather agglomerate on the cell surface. Conclusion: The inhibition effects are thus mainly controlled by the interaction dynamics between bacteria and ZnO, where mixing greatly enhances antibacterial efficacy of all ZnO particles. The efficacy is modulated also by ZnO particle shapes, where hedgehog ZnO has superior effect, in particular at lower concentrations. However, at too low concentrations, ZnO can stimulate bacteria growth and must be thus used with caution.


Assuntos
Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Ouriços-Cacheiros , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Testes de Sensibilidade Microbiana
8.
Molecules ; 26(5)2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33800455

RESUMO

The thin film of N-doped ZnO/CNT nanocomposite was successfully fabricated on soda lime glass substrate by a simple sol-gel drop-coating method. The structural, morphological, chemical, and optical properties of as prepared samples were characterized by a variety of tools such as X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared spectroscopy (FT-IR), and UV-visible spectroscopy. The hexagonal crystalline structure was confirmed from XRD measurement without any other impurity phase detection in samples. The N-doped ZnO/CNT composite showed excellent photo-catalytic activity towards cationic methylene blue (MB) dye degradation with 100% removal rate under UV light irradiation as compared to N-doped ZnO (65%) and pure ZnO (47.36%). The convincing performance has also been observed for the case of visible light irradiation. The enhancement of that photocatalytic activity might be due to narrowing the band gap as well as the reduction of electron-hole pair recombination in ZnO matrix with the incorporation of dopant nitrogen and CNT. It is assumed from the obtained results that N-doped ZnO/CNT nanocomposite thin film can be employed as an economically achievable and ecofriendly method to degrade dye with UV and visible light irradiation. Additionally, density functional theory (DFT) calculations were applied to explore the effect of N-doping on electronic structure of ZnO. The computational study has supported the experimental results of significant band gap contraction, which leads to the maximum absorption towards higher wavelength and no appreciable change of lattice parameters after doping. A conceivable photocatalytic mechanism of N-doped ZnO/CNT nanocomposite has been proposed as well.


Assuntos
Nanocompostos/química , Nitrogênio/química , Óxido de Zinco/química , Catálise , Contaminação de Medicamentos , Luz , Microscopia Eletrônica de Varredura/métodos , Processos Fotoquímicos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Raios Ultravioleta , Difração de Raios X/métodos
9.
Sci Rep ; 11(1): 8692, 2021 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-33888738

RESUMO

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.


Assuntos
Ouro/farmacologia , Vírus da Influenza A Subtipo H1N1/fisiologia , Virus da Influenza A Subtipo H5N1/fisiologia , SARS-CoV-2/fisiologia , Prata/farmacologia , Óxido de Zinco/farmacologia , Enzima de Conversão de Angiotensina 2/metabolismo , Antivirais/química , Antivirais/farmacologia , Farmacorresistência Viral/efeitos dos fármacos , Aditivos Alimentares/farmacologia , Ouro/química , Células HEK293 , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Nanopartículas Metálicas/química , Nanocompostos/química , Oseltamivir/farmacologia , Tamanho da Partícula , Ligação Proteica/efeitos dos fármacos , SARS-CoV-2/efeitos dos fármacos , Prata/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Internalização do Vírus/efeitos dos fármacos , Óxido de Zinco/química
10.
Sci Rep ; 11(1): 8692, 2021 04 22.
Artigo em Inglês | MEDLINE | ID: covidwho-1199310

RESUMO

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.


Assuntos
Ouro/farmacologia , Vírus da Influenza A Subtipo H1N1/fisiologia , Virus da Influenza A Subtipo H5N1/fisiologia , SARS-CoV-2/fisiologia , Prata/farmacologia , Óxido de Zinco/farmacologia , Enzima de Conversão de Angiotensina 2/metabolismo , Antivirais/química , Antivirais/farmacologia , Farmacorresistência Viral/efeitos dos fármacos , Aditivos Alimentares/farmacologia , Ouro/química , Células HEK293 , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Nanopartículas Metálicas/química , Nanocompostos/química , Oseltamivir/farmacologia , Tamanho da Partícula , Ligação Proteica/efeitos dos fármacos , SARS-CoV-2/efeitos dos fármacos , Prata/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Internalização do Vírus/efeitos dos fármacos , Óxido de Zinco/química
11.
Int J Mol Sci ; 22(9)2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33925617

RESUMO

The development of drug-resistant microorganisms has become a critical issue for modern medicine and drug discovery and development with severe socio-economic and ecological implications. Since standard and conventional treatment options are generally inefficient, leading to infection persistence and spreading, novel strategies are fundamentally necessary in order to avoid serious global health problems. In this regard, both metal and metal oxide nanoparticles (NPs) demonstrated increased effectiveness as nanobiocides due to intrinsic antimicrobial properties and as nanocarriers for antimicrobial drugs. Among them, gold, silver, copper, zinc oxide, titanium oxide, magnesium oxide, and iron oxide NPs are the most preferred, owing to their proven antimicrobial mechanisms and bio/cytocompatibility. Furthermore, inorganic NPs can be incorporated or attached to organic/inorganic films, thus broadening their application within implant or catheter coatings and wound dressings. In this context, this paper aims to provide an up-to-date overview of the most recent studies investigating inorganic NPs and their integration into composite films designed for antimicrobial therapies.


Assuntos
Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Nanocompostos/uso terapêutico , Animais , Antibacterianos , Anti-Infecciosos/uso terapêutico , Cobre/química , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Compostos Férricos/química , Ouro/química , Humanos , Magnésio/química , Prata/química , Titânio/química , Óxido de Zinco/química
12.
Int J Mol Sci ; 22(9)2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33925962

RESUMO

Functional nanocomposites with biopolymers and zinc oxide (ZnO) nanoparticles is an emerging application of photocatalysis in antifouling coatings. The reduced chemical stability of ZnO in the acidic media in which chitosan is soluble affects the performance of chitosan nanocomposites in antifouling applications. In this study, a thin shell of amorphous tin dioxide (SnOx) was grown on the surface of ZnO to form ZnO-SnOx core-shell nanoparticles that improved the chemical stability of the photocatalyst nanoparticles, as examined at pH 3 and 6. The photocatalytic activity of ZnO-SnOx in the degradation of methylene blue (MB) dye under visible light showed a higher efficiency than that of ZnO nanoparticles due to the passivation of electronic defects. Chitosan-based antifouling coatings with varying percentages of ZnO or ZnO-SnOx nanoparticles, with or without the glutaraldehyde (GA) crosslinking of chitosan, were developed and studied. The incorporation of photocatalysts into the chitosan matrix enhanced the thermal stability of the coatings. Through a mesocosm study using running natural seawater, it was found that chitosan/ZnO-SnOx/GA coatings enabled better inhibition of bacterial growth compared to chitosan coatings alone. This study demonstrates the antifouling potential of chitosan nanocomposite coatings containing core-shell nanoparticles as an effective solution for the prevention of biofouling.


Assuntos
Quitosana/química , Nanocompostos/química , Óxido de Zinco/química , Antibacterianos/farmacologia , Incrustação Biológica/prevenção & controle , Biopolímeros , Microscopia Eletrônica de Varredura/métodos , Nanopartículas/química , Oxidantes Fotoquímicos/química , Compostos de Estanho/química
13.
Molecules ; 26(7)2021 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-33916520

RESUMO

In the present work, the properties of ZnO nanoparticles obtained using an eco-friendly synthesis (biomediated methods in microwave irradiation) were studied. Saponaria officinalis extracts were used as both reducing and capping agents in the green nanochemistry synthesis of ZnO. Inorganic zinc oxide nanopowders were successfully prepared by a modified hydrothermal method and plant extract-mediated method. The influence of microwave irradiation was studied in both cases. The size, composition, crystallinity and morphology of inorganic nanoparticles (NPs) were investigated using dynamic light scattering (DLS), powder X-ray diffraction (XRD), SEM-EDX microscopy. Tunings of the nanochemistry reaction conditions (Zn precursor, structuring agent), ZnO NPs with various shapes were obtained, from quasi-spherical to flower-like. The optical properties and photocatalytic activity (degradation of methylene blue as model compound) were also investigated. ZnO nanopowders' antibacterial activity was tested against Gram-positive and Gram-negative bacterial strains to evidence the influence of the vegetal extract-mediated synthesis on the biological activity.


Assuntos
Antibacterianos/farmacologia , Nanopartículas Metálicas/química , Saponaria/química , Óxido de Zinco/farmacologia , Antibacterianos/síntese química , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Catálise , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Química Verde , Humanos , Luz , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Micro-Ondas , Processos Fotoquímicos , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Óxido de Zinco/química
14.
Molecules ; 26(9)2021 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-33923041

RESUMO

In this work, mesoporous TiO2-modified ZnO quantum dots (QDs) were immobilised on a linear low-density polyethylene (LLDPE) polymer using a solution casting method for the photodegradation of tetracycline (TC) antibiotics under fluorescent light irradiation. Various spectroscopic and microscopic techniques were used to investigate the physicochemical properties of the floating hybrid polymer film catalyst (8%-ZT@LLDPE). The highest removal (89.5%) of TC (40 mg/L) was achieved within 90 min at pH 9 due to enhanced water uptake by the LDDPE film and the surface roughness of the hybrid film. The formation of heterojunctions increased the separation of photogenerated electron-hole pairs. The QDs size-dependent quantum confinement effect leads to the displacement of the conduction band potential of ZnO QDs to more negative energy values than TiO2. The displacement generates more reactive species with higher oxidation ability. The highly stable film photocatalyst can be separated easily and can be repeatedly used up to 8 cycles without significant loss in the photocatalytic ability. The scavenging test indicates that the main species responsible for the photodegradation was O2●-. The proposed photodegradation mechanism of TC was demonstrated in further detail based on the intermediates detected by LC-time-of-flight/mass spectrometry (LC/TOF-MS).


Assuntos
Fluorescência , Fotólise , Polímeros/química , Tetraciclina/química , Polietileno/química , Tetraciclina/efeitos adversos , Titânio/química , Óxido de Zinco/química
15.
Molecules ; 26(5)2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33807651

RESUMO

A series of cobalt-inserted copper zinc ferrites, Cu0.6CoxZn0.4-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4) having cubic spinel structure were prepared by the coprecipitation method. Various characterization techniques, including XRD, FTIR, UV-vis and I-V were used to investigate structural optical and electrical properties, respectively. The lattice constant was observed to be decreased as smaller ionic radii Co2+ (0.74 Å) replaced the higher ionic radii Zn2+ (0.82 Å). The presence of tetrahedral and octahedral bands was confirmed by FTIR spectra. Optical bandgap energy was determined in the range of 4.44-2.05 eV for x = 0.0 to 0.4 nanoferrites, respectively. DC electrical resistivity was measured and showed an increasing trend (5.42 × 108 to 6.48 × 108 Ω·cm) with the addition of cobalt contents as cobalt is more conductive than zinc. The range of DC electrical resistivity (108 ohm-cm) makes these nanomaterials potential candidates for telecommunication devices.


Assuntos
Compostos Férricos/química , Cobre/química , Condutividade Elétrica , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Óxido de Zinco/química
16.
Molecules ; 26(7)2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33916062

RESUMO

The objective of this study was to determine the oxidative stress and the physiological and antioxidant responses of coriander plants (Coriandrum sativum) grown for 58 days in soil with zinc oxide nanoparticles (ZnO NPs) and zinc sulfate (ZnSO4) at concentrations of 0, 100, 200, 300, and 400 mg of Zn/kg of soil. The results revealed that all Zn compounds increased the total chlorophyll content (CHLt) by at least 45%, compared to the control group; however, with 400 mg/kg of ZnSO4, chlorophyll accumulation decreased by 34.6%. Zn determination by induction-plasma-coupled atomic emission spectrometry (ICP-AES) showed that Zn absorption in roots and shoots occurred in plants exposed to ZnSO4 at all concentrations, which resulted in high levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA). Only at 400 mg/kg of ZnSO4, a 78.6% decrease in the MDA levels was observed. According to the results, the ZnSO4 treatments were more effective than the ZnO NPs to increase the antioxidant activity of catalase (CAT), ascorbate peroxidase (APX), and peroxidases (POD). The results corroborate that phytotoxicity was higher in plants subjected to ZnSO4 compared to treatments with ZnO NPs, which suggests that the toxicity was due to Zn accumulation in the tissues by absorbing dissolved Zn++ ions.


Assuntos
Coriandrum/crescimento & desenvolvimento , Coriandrum/metabolismo , Peroxidação de Lipídeos , Nanopartículas Metálicas/química , Desenvolvimento Vegetal , Óxido de Zinco/química , Sulfato de Zinco/química , Antioxidantes/metabolismo , Biomarcadores , Coriandrum/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Nanopartículas Metálicas/ultraestrutura , Oxirredução , Fotossíntese , Compostos Fitoquímicos/química , Desenvolvimento Vegetal/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Análise Espectral , Óxido de Zinco/metabolismo , Óxido de Zinco/farmacologia , Sulfato de Zinco/metabolismo , Sulfato de Zinco/farmacologia
17.
Molecules ; 26(8)2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33920949

RESUMO

Mycotoxigenic fungi have attracted special attention due to their threat to food security and toxicity to human health. Aqueous extract of Zingiber officinale Roscoe was used as reducing and capping agent for the synthesis of silver (AgNPs), copper (CuNPs), and zinc oxide (ZnONPs) nanoparticles. UV-Visible spectra of the AgNPs, CuNPs, and ZnONPs showed absorption peaks at λmax 416 nm, 472 nm, and 372 nm, respectively. Zeta potential of AgNPs, CuNPs, and ZnONPs were -30.9, -30.4 and -18.4 mV, respectively. ZnONPs showed the highest activity against Aspergillus awamori ZUJQ 965830.1 (ZOI 20.9 mm and MIC 24.7 µg/mL). TEM micrographs of ZnONPs-treated A. awamori showed cracks and pits in the cell wall, liquefaction of the cytoplasmic content, making it less electron-dense. The sporulation and ochratoxin A production of A. awamori was inhibited by ZnONPs in a concentration-dependent pattern. The inhibition percentage of OTA were 45.6, 84.78 and 95.65% for 10, 15, 20 of ZnONPs/mL, respectively.


Assuntos
Antibacterianos/química , Gengibre/química , Nanopartículas Metálicas/química , Aspergillus/efeitos dos fármacos , Ocratoxinas/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Óxido de Zinco/química
18.
Int J Mol Sci ; 22(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806904

RESUMO

This study was conducted to compare the effects of commercially available (C) and green synthesized (GS) Zinc oxide nanoparticles (ZnO-NPs) on immunological responses of common carp (Cyprinus carpio) skin mucus. GS ZnO-NPs were generated using Thymus pubescent and characterized by UV-vis diffuse reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). Fish (n = 150) were randomly allocated into five groups in triplicate and received a waterborne concentration of 0% (control), 25%, and 50% of LC50 96 h of commercially available (C1 and C2) and green synthesized ZnO-NPs (GS1 and GS2) for 21 days. Results from XRD displayed ZnO-NPs with 58 nm in size and UV-vis DRS, EDX, and FT-IR analysis showed that some functional groups from plant extract bonded to the surface of NPs. The SEM images showed that ZnO-NPs have conical morphology. Acute toxicity study showed a higher dose of LC5096h for green synthesized ZnO-NPs (78.9 mg.L-1) compared to the commercial source (59.95 mg.L-1). The highest activity of lysozyme and alternative complement activity (ACH50) were found in control and GS1 groups. A significant decrease in alkaline phosphatase activity (ALP) was found in C1 and C2 groups compared to other treatments. Protease activity (P) was significantly decreased in the C2 group compared to the control and GS groups. Total immunoglobulin (total Ig) content was the highest in the control. In addition, total Ig in the GS1 group was higher than GS2. The exposure to ZnO-NPs lowered total protein content in all experimental groups when compared to control. Present findings revealed lower induced immunosuppressive effects by green synthesized ZnO-NPs on key parameters of fish skin mucus.


Assuntos
Carpas/fisiologia , Fatores Imunológicos/síntese química , Fatores Imunológicos/farmacologia , Nanopartículas Metálicas/química , Muco/metabolismo , Pele/efeitos dos fármacos , Pele/metabolismo , Óxido de Zinco/química , Animais , Técnicas de Química Sintética , Química Verde , Nanopartículas Metálicas/ultraestrutura , Análise Espectral
19.
Photochem Photobiol Sci ; 20(2): 189-244, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33721254

RESUMO

Sunscreens have now been around for decades to mitigate the Sun's damaging ultraviolet (UV) radiation which, although essential for the existence of life, is a recognized prime carcinogen. Accordingly, have suncreams achieved their intended purposes towards protection against sunburns, skin photo-ageing and the like? Most importantly, however, have they provided the expected protection against skin cancers that current sunscreen products claim to do? In the last two decades, there have been tens, if not hundreds of studies on sunscreens with respect to skin protection against UVB (280‒320 nm)-traditionally sunscreens with rather low sun protection factors (SPF) were intended to protect against this type of radiation-and UVA (320‒400 nm) radiation; a distinction between SPF and UVA protection factor (UVA-PF) is made. Many of the studies of the last two decades have focused on protection against the more skin-penetrating UVA radiation. This non-exhaustive article reviews some of the important facets of what is currently known about sunscreens with regard (i) to the physical UV filters titanium dioxide (TiO2) and zinc oxide (ZnO) and the mostly photo-unstable chemical UVB/UVA filters (e.g., octinoxate (OMC) and avobenzone (AVO), among others), (ii) to novel chemical sunscreen agents, (iii) to means that minimize the breakdown of chemical filters and improve their stability when exposed to UV sunlight, (iv) to SPF factors, and (v) to a short discussion on non-melanoma skin cancers and melanoma. Importantly, throughout the article we allude to the safety aspects of sunscreens and at the end ask the question: do active ingredients in sunscreen products pose a risk to human health, and what else can be done to enhance protection? Significant loss of skin protection from two well-known commercial suncreams when exposed to simulated UV sunlight. Cream I: titanium dioxide, ethylhexyl triazone, avobenzone, and octinoxate; Cream II: octyl salicylate, oxybenzone, avobenzone, and octinoxate.


Assuntos
Pele/efeitos dos fármacos , Protetores Solares/farmacologia , Estabilidade de Medicamentos , Humanos , Propiofenonas/química , Propiofenonas/farmacologia , Propiofenonas/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos da radiação , Pele/efeitos da radiação , Neoplasias Cutâneas/prevenção & controle , Fator de Proteção Solar , Protetores Solares/química , Protetores Solares/uso terapêutico , Titânio/química , Titânio/farmacologia , Titânio/uso terapêutico , Raios Ultravioleta , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Óxido de Zinco/uso terapêutico
20.
Carbohydr Polym ; 260: 117820, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33712163

RESUMO

A high-performance flexible conductive substrate is one of the key components for developing promising wearable devices. Concerning this, a sustainable, flexible, transparent, and conductive cellulose/ZnO/AZO (CZA) film was developed in this study. The cellulose was used as the transparent substrate. The added AZO was as the conductive layer and ZnO functioned as an interface buffer layer. Results showed that the interface buffer layer of ZnO effectively alleviated the intrinsic incompatibility of organic cellulose and inorganic AZO, resulting in the improvement of the performance of CZA film. In compared with the controlled cellulose/AZO (CA) film with 365 Ω/sq sheet resistance and 87% transmittance, this CZA film featured a low conductive sheet resistance of 115 Ω/sq and high transmittance of 89%, as well as low roughness of 1.85 nm Moreover, the existence of conducive ZnO buffer layer enabled the conductivity of CZA film to be stable under the bending treatment. Herein, a flexible electronic device was successfully prepared with the biomass materials, which would be available by a roll-to-roll production process.


Assuntos
Celulose/química , Eletrônica , Alumínio/química , Condutividade Elétrica , Óxido de Zinco/química
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