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1.
J Sci Food Agric ; 100(2): 570-577, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31588994

RESUMO

BACKGROUND: Among nanomaterials, Ti and ZnO nanoparticles are often chosen as preservation materials because of their antibacterial properties. Chitosan, as a natural biopolymer, has potential because of its abundance, compatibility and antibacterial properties. To improve the physicochemical and preservation properties of in situ SiOx chitosan (CS) composite coating, Ti/ZnO/SiOx CS composite coatings were prepared with Ti-doped ZnO (Ti/ZnO) nanorods and nanoballs. The composite coating structures were characterized by Fourier transform infrared, X-ray diffraction and scanning electron microscopy, and their physicochemical and preservation properties were determined simultaneously. RESULTS: The results show that the Ti/ZnO nanoparticles are beneficial to homogeneous dispersion of in situ synthesized nano SiOx in the CS coating, and that Ti/ZnO nanoballs have better dispersion than Ti/ZnO nanorods. Moreover, strong hydrogen bonds are formed among Ti/ZnO nanoparticles and in situ synthesized nano SiOx and CS molecules, and the primary structure of CS is disorganized. Thereby, the gas permeabilities and mechanical properties of the CS coatings are improved due to modification of Ti/ZnO nanoparticles, and the Ti/ZnO nanoballs/SiOx CS composite coating is optimal. The preservation properties of the CS coatings on Sciaenops ocellatus are significantly improved, and those of Ti/ZnO/in situ SiOx CS composite coatings are superior. CONCLUSION: The preservation properties of the CS composite coatings on S. ocellatus are significant, and the Ti/ZnO nanoballs/SiOx CS composite coating is even better. Therefore, the co-modification method of in situ nanoparticles and antibacterial nanoparticles may be a promising method to improve the preservation properties of CS coatings. © 2019 Society of Chemical Industry.


Assuntos
Antibacterianos/química , Quitosana/química , Titânio/química , Óxido de Zinco/química , Nanopartículas/química , Difração de Raios X
2.
J Colloid Interface Sci ; 559: 313-323, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31675662

RESUMO

Antibiotic resistance is a common phenomenon observed during treatment with antibacterials. Use of nanozymes, especially those with synergistic enzyme-like activities, as antibacterials could overcome this problem, but their synthesis is limited by their high cost and/or complex production process. Herein, vanadium oxide nanodots (VOxNDs) were prepared via a one-step bottom-up ethanol-thermal method using vanadium trichloride as the precursor. VOxNDs alone possess bienzyme mimics of peroxidase and oxidase. Accordingly, highly efficient antibacterials against drug-resistant bacteria can be obtained through synergistic catalysis; the oxidase-like activity decomposes O2 to generate superoxide anion radical (O2-) and hydroxyl radicals (OH), and the intrinsic peroxidase-like activity can further induce the production of OH from external H2O2. Consequently, H2O2 concentration could decrease up to four magnitude orders with VOxNDs to achieve an antibacterial efficacy similar to that of H2O2 alone. Wound healing in vivo further confirms the high antibacterial efficiency, good biocompatibility, and application potential of the synergistic antibacterial system due to the "nano" structure of VOxNDs. The method of synthesis of nanodot antibacterials described in this paper is inexpensive, and the results of this study reveal the multi-enzymatic synergism of nanozymes.


Assuntos
Antibacterianos/química , Nanopartículas Metálicas/química , Óxidos/química , Compostos de Vanádio/química , Cicatrização/efeitos dos fármacos , Animais , Materiais Biocompatíveis/química , Materiais Biomiméticos/química , Catálise , Sobrevivência Celular/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Células HeLa , Células Endoteliais da Veia Umbilical Humana , Humanos , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Peroxidases/metabolismo , Ratos Sprague-Dawley , Staphylococcus aureus/efeitos dos fármacos
3.
J Colloid Interface Sci ; 558: 47-54, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31580954

RESUMO

The unique antibacterial characteristics of Ag nanomaterials offer a wide potential range of applications, but achieving rapid and durable antibacterial efficacy is challenging. This is because the speed and durability of the antibacterial function make conflicting demands on the structural design: the former requires the direct exposure of Ag to the surrounding environment, whereas the durability requires Ag to be protected from the environment. To overcome this incompatibility, we synthesize sandwich-structured polydopamine shells decorated both internally and externally with Ag nanoparticles, which exhibit prompt and lasting bioactivity in applications. These shells are biocompatible and can be used in vivo to counter bacterial infection caused by methicillin-resistant Staphylococcus aureus superbugs and to inhibit biofilm formation. This work represents a new paradigm for the design of composite materials with enhanced antibacterial properties.


Assuntos
Antibacterianos/química , Materiais Biocompatíveis/química , Indóis/química , Nanopartículas Metálicas/química , Polímeros/química , Prata/química , Animais , Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Escherichia coli/efeitos dos fármacos , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Ratos , Ratos Sprague-Dawley
4.
Food Chem ; 308: 125633, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31644968

RESUMO

The objective of this study was to evaluate the in vitro antimicrobial and antioxidant activities of different bran extracts and concentrations, and their influence on the parameters of a mayonnaise-type emulsion. To that end, first ethanol and then water were used to extract two rice bran extracts (RBE) from rice bran. Both these extracts were then added at two different concentrations (0.5 and 2%) to the emulsions that were subsequently analysed after seven days under two different storage temperatures, 4 °C and 20 °C. The antioxidant and antimicrobial ability of the extracts were evaluated, along with a control and a synthetic antioxidant. Results indicate the positive effect of rice bran extracts as additives in the food matrix. Ethanolic rice bran extract (EE) at 2% decreased the oxidation as well as mould and yeast proliferation and preserved the emulsion structure, while the other treatments acted in a similar way although their effect was less pronounced.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Oryza/química , Extratos Vegetais/farmacologia , Antibacterianos/química , Antioxidantes/química , Condimentos , Emulsões , Escherichia coli/efeitos dos fármacos , Listeria/efeitos dos fármacos , Oxirredução , Extratos Vegetais/química
5.
J Environ Sci (China) ; 87: 228-237, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31791495

RESUMO

The prevalent presence of fluoroquinolone antibiotics in aquatic environments has attracted considerable attention because of their harmful effects on humans and the ecological environment. Magnesium hydroxide nanocrystals were found to act as a simple and effective adsorbent to remove low-concentration ciprofloxacin (CIP) in aqueous solution. The as-prepared Mg(OH)2 nanocrystals exhibited excellent CIP adsorption performance and high selectivity toward CIP molecules compared with other antibiotics or aromatics, e.g., norfloxacin (NOR) and eosin B (EB). The adsorbent showed pH-dependent adsorption, indicating that the adsorption process is probably dominated by an electrostatic interaction mechanism. In addition, structural analysis of the adsorbent indicated that coordination and hydrogen bonding between CIP and Mg(OH)2 nanocrystal might also be involved in the adsorption process. Moreover, the adsorbent could be easily recovered by pyrolysis and hydration without significant reduction of adsorption capacity. The superior adsorption behavior of Mg(OH)2 nanocrystal indicates that it may serve as a potential adsorbent material candidate for the selective removal of CIP from aquatic environments.


Assuntos
Antibacterianos/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Antibacterianos/química , Ciprofloxacino/química , Fluoroquinolonas , Cinética , Poluentes Químicos da Água/química
6.
Biomed Khim ; 65(6): 468-476, 2019 Oct.
Artigo em Russo | MEDLINE | ID: mdl-31876517

RESUMO

We present a novel computational ligand-based virtual screening approach with scaffold hopping capabilities for the identification of novel inhibitors of ß-lactamases which confer bacterial resistance to ß-lactam antibiotics. The structures of known ß-lactamase inhibitors were used as query ligands, and a virtual in silico screening a database of 8 million drug-like compounds was performed in order to select the ligands with similar shape and charge distribution. A set of numerical descriptors was used such as chirality, eigen spectrum of matrices of interatomic distances and connectivity together with higher order moment invariants that showed their efficiency in the field of pattern recognition but have not yet been employed in drug discovery. The developed scaffold-hopping approach was applied for the discovery of analogues of four allosteric inhibitors of serine ß-lactamases. After a virtual in silico screening, the effect of two selected ligands on the activity of TEM type ß-lactamase was studied experimentally. New non-ß-lactam inhibitors were found that showed more effective inhibition of ß-lactamases compared to query ligands.


Assuntos
Antibacterianos/química , Descoberta de Drogas , Inibidores de beta-Lactamases/química , Simulação por Computador , Bases de Dados de Compostos Químicos , Modelos Químicos
7.
Pol J Microbiol ; 68(4): 515-525, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31880895

RESUMO

The progress of research on silver nanoparticles (AgNPs) has led to their inclusion in many consumer products (chemicals, cosmetics, clothing, water filters, and medical devices) as a biocide. Despite the widespread use of AgNPs, their biocidal activity is not yet fully understood and is usually associated with various factors (size, composition, surface, red-ox potential, and concentration) and, obviously, specific features of microorganisms. There are merely a few studies concerning the interaction of molds with AgNPs. Therefore, the determination of the minimal AgNPs concentration required for effective growth suppression of five fungal species (Paecilomyces variotii, Penicillium pinophilum, Chaetomium globosum, Trichoderma virens, and Aspergillus brasiliensis), involved in the deterioration of construction materials, was particularly important. Inhibition of bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli) and yeasts (Candida albicans and Yarrowia lipolytica) was also assessed as the control of AgNPs effectiveness. AgNPs at the concentrations of 9-10.7 ppm displayed high inhibitory activity against moulds, yeast, and bacteria. The TEM images revealed that 20 nm AgNPs migrated into bacterial, yeast, and fungal cells but aggregated in larger particles (50-100 nm) exclusively inside eukaryotic cells. The aggregation of 20 nm AgNPs and particularly their accumulation in the cell wall, observed for A. brasiliensis cells, are described here for the first time.The progress of research on silver nanoparticles (AgNPs) has led to their inclusion in many consumer products (chemicals, cosmetics, clothing, water filters, and medical devices) as a biocide. Despite the widespread use of AgNPs, their biocidal activity is not yet fully understood and is usually associated with various factors (size, composition, surface, red-ox potential, and concentration) and, obviously, specific features of microorganisms. There are merely a few studies concerning the interaction of molds with AgNPs. Therefore, the determination of the minimal AgNPs concentration required for effective growth suppression of five fungal species (Paecilomyces variotii, Penicillium pinophilum, Chaetomium globosum, Trichoderma virens, and Aspergillus brasiliensis), involved in the deterioration of construction materials, was particularly important. Inhibition of bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli) and yeasts (Candida albicans and Yarrowia lipolytica) was also assessed as the control of AgNPs effectiveness. AgNPs at the concentrations of 9­10.7 ppm displayed high inhibitory activity against moulds, yeast, and bacteria. The TEM images revealed that 20 nm AgNPs migrated into bacterial, yeast, and fungal cells but aggregated in larger particles (50­100 nm) exclusively inside eukaryotic cells. The aggregation of 20 nm AgNPs and particularly their accumulation in the cell wall, observed for A. brasiliensis cells, are described here for the first time.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Prata/farmacologia , Antibacterianos/química , Antifúngicos/química , Bactérias/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Prata/química
8.
J Photochem Photobiol B ; 201: 111670, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31706087

RESUMO

Synthesis of nanoparticles using plant sources as reducing agent has become important, as physical and chemical methods are costlier and affects environment. Hence it is important to develop environment friendly nanoparticle synthesis by avoiding the use of toxic chemicals. The present study aimed to synthesize silver nanoparticles (Ag Nps) and gold nanoparticles (AuNps) using Musa acuminata colla flower and its pharmaceutical activity against extended spectrum beta-lactamase (ESBL) gene producing bacteria and anticancer efficacy. The synthesized Ag and Au NPs were analysed by means of UV-Vis, FTIR, XRD,SEM and EDAX evidenced the bioreduction of Ag+ ions to Ag0 and Au3+ ions to Au0 respectively. Both nanoparticles and flower extracts were studied for antibacterial activity of ESBL gene producing bacteria by disc diffusion and microdilution (Resazurin) method. In vitro anticancer efficacy (MCF-7) and toxicity (VERO) of AgNPs, AuNPs, aqueous extract and ethanol extract of flowers were performed by MTT assay. IC50 value for DPPH analysis was at 390 µg and 460 µg for ethanol and aqueous extract respectively. Total antioxidant content was found be 740 µg/mg and 460 µg/mg for ethanol and aqueous extract. GCMS analysis authenticated the existence of the compounds namely, 9,12-octadecadienoic acid(z,z)- and n-hexadecanoic acid in the crude extract of the samples. Among the samples, AgNPs had best antibacterial activity. AgNPs and AuNPs were confirmed by colour change to reddish brown and ruby red. Further ƛmax were obtained at 474 and 540 nm by UV - visible spectrum. SEM analysis revealed the particle size ranges from 12.6 to 15.7 nm for silver and 10.1 to 15.6 nm for gold nanoparticles. The EDAX spectrum shows a strong signal for elemental Ag and Au at ~ 3 keV and 1.5 keV. The XRD patterns for silver and gold nanoparticles at 36.701, 42.900, 63.281 and 76.398 corresponding to the lattice planes 2.4467, 2.1064, 1.46839, 1.24564 nm and 27.32, 36.7228, 39.56, 42.888, 63.253, 63.253, 65.02 and 76.383 corresponding to the lattice planes 3.262, 2.44530, 2.276, 2.1070, 1.46897, 1.4332 and 1.24585 nm. The IC50 values for MCF-7 and VERO cells were 30.0 µg/ml and 55.0 µg/ml respectively.


Assuntos
Antibacterianos/química , Antineoplásicos/química , Ouro/química , Musa/química , Prata/química , Animais , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Flores/química , Flores/metabolismo , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Química Verde , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Musa/metabolismo , Extratos Vegetais/química , Células Vero
9.
J Photochem Photobiol B ; 201: 111683, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31710928

RESUMO

In recent years dendrimers have fascinated the investigators towards targeted drug delivery because of their versatile framework and exhibit immense potentiality in entrapping drug moieties through host-guest interactions and serve as a promising vector in biological applications. The current investigation is focused on developing pegylated citric acid cefotaxime dendrimers through the divergent method and its characterization through spectroscopic, microscopic, thermal and microscopic techniques. Among the spectroscopic techniques, 1H NMR and 13C NMR elucidated the key functional groups at various chemical shifts while ESI-MS pointed out the molecular weight of cefotaxime sodium in various generations. Similarly, FTIR, DSC, and AFM investigations detailed that the generations are devoid of incompatibilities, structural deformities and can be opted for targeted drug delivery. The drug entrapment studies and in-vitro drug release studies highlight CFTX G5 containing 92.4% entrapment efficacy and 83.8% drug release in 48 h and specifies a sustain release characteristics. In connection to the above, the in-vivo studies reveal a potent antibacterial activity against various gram-positive and gram-negative microorganisms with a decreased hemolysis and cytotoxicity effects and reflect a high margin of safety regarding pegylated CFTX dendrimers. Further, the antibacterial activities are supported through confocal microscopy that clarified the cellular uptake of dendritic molecules and their internalization.


Assuntos
Cefotaxima/química , Ácido Cítrico/química , Dendrímeros/química , Nanoestruturas/química , Células A549 , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Cefotaxima/metabolismo , Cefotaxima/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Meia-Vida , Hemólise/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Nanoestruturas/toxicidade , Polietilenoglicóis/química
10.
J Photochem Photobiol B ; 200: 111650, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31698288

RESUMO

The biosynthesis of ZnO nanoparticles was synthesized by biogenic reduction of applied Cucurbita seed extract. The powder X-ray diffraction pattern displayed the high crystalline nature of synthesized ZnO nanoparticles and the crystallite size was calculated at 35 nm range. The Fourier Transform Infra-Red study revealed the functional groups of biogenic reduction and vibrational bands present in the synthesized nanoparticles. The UV-Visible analysis explained the SPR absorption peak at 371 nm. The Photoluminescence study revealed the strong red shoulder emission peak at 665 nm. The particle size analyzer displayed the particle size occupies majorly on 45-65 nm. The SEM analysis pointed the ZnO nanoparticles under rod, rectangular and hexagonal shapes were procured. The EDAX spectrum also mapping exposed the purity of formed ZnO nanoparticles with just Zn and O peaks. The HRTEM analysis exposed the hexagonal shape wurtzite structure ZnO particles formation. The physiochemical analysis revealed general nature of Cucurbita seed powder moreover which explained the phytochemicals involved in biogenic reduction of ZnO nanoparticles. The formed ZnO nanoparticles exhibited good antibacterial activity on E. coli, Bacillus pumilus, and Salmonella typhi bacteria. The cytotoxicity study stated the good toxicity on E. coli AB 1157. The antifungal activity showed a better effect on Aspergillus flavus and Aspergillus niger fungi. The antioxidant activity clarified the good free radical scavenging action. The anti larvicidal activity expressed a better impact on Culex tritaeniorhynchus mosquito larvae.


Assuntos
Cucurbita/química , Culex/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Extratos Vegetais/química , Óxido de Zinco/química , Animais , Antibacterianos/biossíntese , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Aspergillus niger/efeitos dos fármacos , Cucurbita/metabolismo , Culex/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Química Verde , Larva/efeitos dos fármacos , Nanopartículas Metálicas/química , Tamanho da Partícula , Sementes/química , Sementes/metabolismo
11.
J Photochem Photobiol B ; 200: 111622, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31678034

RESUMO

Seaweeds are considered to be one of the richest bio-reserves, comprising of numerous bioactive compounds with versatile properties and multiple activities. The present study examined the antibacterial activity of two types of seaweeds, Ulva lactuca (green) and Stoechospermum marginatum (brown) collected from Oman Coastal region against five multidrug-resistant bacteria. The aqueous extracts of the seaweeds showed better antibacterial activity compared to methanol extracts. The results of the antibacterial assay revealed the excellent inhibitory effects of U.lactuca with the maximum activity against E.coli(8 mm) followed by K.pneumonia(4 mm) and S.typhi(2 mm). S.marginatum formed a clear zone of inhibition only against E.coli(3 mm).The major phytochemical constituents identified in both the types of seaweeds were Alkaloids, Terpenoids, Saponins, Flavonoids, and Steroids. Fourier transform infrared spectroscopy (FTIR) results confirmed the presence of alcoholic/phenolic groups, and amide groups in the seaweed extracts. Gas chromatography-mass spectrometry (GC-MS) results evidenced the presence of bioactive compounds such as 5-Octadecenal, 1-Tricosanol, Neophytadiene, Lactaropallidin, Phytol, Fenretinide, Lucenin, Vincadifformine in U.lactuca. Additionally, U.lactuca displayed better antioxidant activity (33.05%) in the DPPH free radical scavenging activity test compared to the S.marginatum (21.51%). Thus, the green seaweed U.lactuca could be considered as a potential source of natural antioxidant and antibacterial agents for food and pharmaceutical products.


Assuntos
Antibacterianos/química , Feófitas/química , Extratos Vegetais/química , Ulva/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antioxidantes/química , Bioprospecção , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Feófitas/metabolismo , Ulva/metabolismo
12.
Chem Commun (Camb) ; 55(87): 13104-13107, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31612170

RESUMO

We designed a few polymyxin derivatives which exhibit broad-spectrum antimicrobial activity. Lead compound P1 could disrupt bacterial membranes rapidly without developing resistance, inhibit biofilms formed by E. coli, and exhibit excellent in vivo activity in an MRSA-infected thigh burden mouse model.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Polimixinas/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Biofilmes/efeitos dos fármacos , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Conformação Molecular , Polimixinas/síntese química , Polimixinas/química
13.
J Appl Oral Sci ; 27: e20180663, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31596368

RESUMO

OBJECTIVE: To investigate the use of polymethyl methacrylate (PMMA) electrospun fiber mats containing different amounts of polyethylene oxide (PEO) as a doxycycline delivery system and to test antibacterial activity against an oral pathogen. METHODOLOGY: PMMA powders or PEO (mol wt 200 Kd) (10,20,30% w/w/) were dissolved in N, N-dimethylformamide (DMF) to obtain a final polymer concentration of 15% in DMF (w/v). 2% Doxycycline monohydrate was added to the solutions and submitted to vortex mixing. The solution was transferred to a plastic syringe and fit into a nanofiber electrospinning unit. The parameters applied were: voltage at 17.2 kV; distance of 20 cm between the needle tip and the collector plate; target speed at 2 m/min; and transverse speed at 1cm/min. Syringe pump speed was 0.15 mm/min. The drug release analysis was performed by removing aliquots of the drug-containing solution (in PBS) at specific periods. Doxycycline release was quantified using RP-HPLC. Fiber mats from all groups had their antibacterial action tested against S. mutans based on inhibition halos formed around the specimens. The experiments were performed in triplicate. Gravimetric analysis at specific periods was performed to determine any polymer loss. Morphological characterization of the electrospun fibers was completed under an optical microscope followed by SEM analysis. RESULTS: The addition of PEO to the PMMA fibers did not affect the appearance and diameter of fibers. However, increasing the %PEO caused higher doxycycline release in the first 24 h. Fibers containing 30% PEO showed statistically significant higher release when compared with the other groups. Doxycycline released from the fibers containing 20% or 30% of PEO showed effective against S. mutans. CONCLUSION: The incorporation of PEO at 20% and 30% into PMMA fiber mat resulted in effective drug release systems, with detected antibacterial activity against S. mutans.


Assuntos
Antibacterianos/farmacocinética , Doxiciclina/farmacocinética , Nanofibras/química , Polietilenoglicóis/farmacocinética , Polimetil Metacrilato/farmacocinética , Análise de Variância , Antibacterianos/química , Cromatografia Líquida de Alta Pressão/métodos , Doxiciclina/química , Imersão , Microscopia Eletrônica de Varredura , Peso Molecular , Polietilenoglicóis/química , Polimetil Metacrilato/química , Reprodutibilidade dos Testes , Streptococcus mutans/efeitos dos fármacos , Fatores de Tempo , Água/química
14.
J Agric Food Chem ; 67(45): 12393-12401, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31596571

RESUMO

Accumulation of toxic copper in soil and development of copper-resistant pests are emerging challenges currently faced by the agricultural community worldwide. As an alternative, we have developed a ternary zinc chelate solution (TSOL) pesticide where zinc ions are the primary active ingredient. The material is composed of zinc, urea, and hydrogen peroxide. Urea was chosen as it is widely used as a plant fertilizer and can also bind to both zinc and hydrogen peroxide. No phytotoxicity was observed with TSOL on Meyer lemon (Citrus × meyeri) seedlings at a field spray rate of 800 µg/mL Zn metal concentration. Antimicrobial studies showed that TSOL exhibited improved killing efficacy against Escherichia coli and Xanthomonas alfalfae compared to Zn ions alone. Citrus canker field trials in a grapefruit (Chrysopelea paradisi) grove over three years showed that TSOL provided comparable disease protection to copper products at an equivalent or lower metal content.


Assuntos
Antibacterianos/química , Citrus/microbiologia , Peróxido de Hidrogênio/química , Doenças das Plantas/microbiologia , Ureia/química , Zinco/química , Zinco/farmacologia , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Peróxido de Hidrogênio/farmacologia , Folhas de Planta/microbiologia , Ureia/farmacologia , Xanthomonas/efeitos dos fármacos , Xanthomonas/crescimento & desenvolvimento
15.
Int J Nanomedicine ; 14: 7217-7236, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31564875

RESUMO

Prosthesis-associated infections are one of the main causes of implant failure; thus it is important to enhance the long-term antibacterial ability of orthopedic implants. Titanium dioxide nanotubes (TNTs) are biomaterials with good physicochemical properties and biocompatibility. Owing to their inherent antibacterial and drug-loading ability, the antibacterial application of TNTs has received increasing attention. In this review, the process of TNT anodizing fabrication is summarized. Also, the mechanism and the influencing factors of the antibacterial property of bare TNTs are explored. Furthermore, different antibacterial strategies for carrying drugs, as well as modifications to prolong the antibacterial effect and reduce drug-related toxicity are discussed. In addition, antibacterial systems based on TNTs that can automatically respond to infection are introduced. Finally, the currently faced problems are reviewed and potential solutions are proposed. This review provides new insight on TNT fabrication and summarizes the most advanced antibacterial strategies involving TNTs for the enhancement of long-term antibacterial ability and reduction of toxicity.


Assuntos
Antibacterianos/farmacologia , Nanotubos/química , Ortopedia , Próteses e Implantes , Titânio/farmacologia , Antibacterianos/química , Humanos , Propriedades de Superfície
16.
J Agric Food Chem ; 67(45): 12584-12589, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31640344

RESUMO

Lysozyme has emerged to be a promising alternative to traditional antibiotics to deal with the increasing antibiotic resistance of bacteria. However, its application is hampered by its inferior bactericidal activity against Gram-negative bacteria. To address this problem, a novel "enzyme-cascade fluorescent high-throughput screening (HTS) method" was designed and constructed based on detection of fluorescence resonance energy transfer (FRET) and enzyme-cascade reaction of lysozyme and protease. As a proof of concept, site-saturation mutagenesis libraries targeting at residues of the unstructured stretch at the N-terminus of Antheraea pernyi lysozyme were constructed and screened by the proposed HTS method. The isolated lysozyme variants proved to exhibit higher antibacterial activity against Escherichia coli K12, demonstrating the significance of this region for the bactericidal function of lysozyme. The presented cell-based fluorescent HTS method is a new tool for screening lysozyme variants with improved bactericidal efficacy against Gram-negative bacteria and for exploring the sequence-structure-function relationship of lysozyme.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Transferência Ressonante de Energia de Fluorescência/métodos , Ensaios de Triagem em Larga Escala/métodos , Muramidase/química , Muramidase/farmacologia , Animais , Escherichia coli/crescimento & desenvolvimento , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Mariposas/química , Mariposas/genética , Mariposas/metabolismo
17.
J Agric Food Chem ; 67(46): 12696-12708, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31657554

RESUMO

In this study, a type of thiazolium-labeled 1,3,4-oxadiazole thioether bridged by diverse alkyl chain lengths was constructed. The antimicrobial activity of the fabricated thioether toward plant pathogenic bacteria and fungi was then screened. Antibacterial evaluation indicated that title compounds possess specific characteristics that enable them to severely attack three phytopathogens, namely, Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Xanthomonas axonopodis pv. citri with minimal EC50 values of 0.10, 3.27, and 3.50 µg/mL, respectively. Three-dimensional quantitative structure-activity relationship models were established to direct the following excogitation for exploring higher active drugs. The in vivo study against plant bacterial diseases further identified the prospective application of title compounds as alternative antibacterial agents. The proteomic technique, scanning electron microscopy patterns, and fluorescence spectrometry were exploited to investigate the antibacterial mechanism. Additionally, some target compounds performed superior inhibitory actions against three tested fungal strains. In view of their simple molecular architecture and highly efficient bioactivity, these substrates could be further explored as promising surrogates for fighting against plant microbial infections.


Assuntos
Antibacterianos/farmacologia , Oxidiazóis/farmacologia , Sulfetos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Testes de Sensibilidade Microbiana , Oxidiazóis/síntese química , Oxidiazóis/química , Doenças das Plantas/microbiologia , Ralstonia/efeitos dos fármacos , Sulfetos/síntese química , Sulfetos/química , Xanthomonas/efeitos dos fármacos
18.
Chem Pharm Bull (Tokyo) ; 67(10): 1088-1098, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31582628

RESUMO

In this study, we synthesized four series of novel L-homoserine lactone analogs and evaluated their in vitro quorum sensing (QS) inhibitory activity against two biomonitor strains, Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PAO1. Studies of the structure-activity relationships of the set of L-homoserine lactone analogs indicated that phenylurea-containing N-dithiocarbamated homoserine lactones are more potent than (Z)-4-bromo-5-(bromomethylene)-2(5H)-furanone (C30), a positive control for biofilm formation. In particular, compared with C30, QS inhibitor 11f significantly reduced the production of virulence factors (pyocyanin, elastase and rhamnolipid), swarming motility, the formation of biofilm and the mRNA level of QS-related genes regulated by the QS system of PAO1. These results reveal 11f as a potential lead compound for developing novel antibacterial quorum sensing inhibitors.


Assuntos
4-Butirolactona/análogos & derivados , Antibacterianos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , 4-Butirolactona/síntese química , 4-Butirolactona/química , 4-Butirolactona/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Estrutura Molecular , Pseudomonas aeruginosa/crescimento & desenvolvimento , Percepção de Quorum/genética , Relação Estrutura-Atividade
19.
J Agric Food Chem ; 67(38): 10791-10799, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31497956

RESUMO

Very weak signals of fragment ions of nosiheptide could be observed using liquid chromatography-tandem mass spectrometry. The preparation of 4-hydroxymethyl-3-methyl-1H-indole-2-carboxylic acid (HMIA), a specific fragment of nosiheptide, by alkaline hydrolysis is described. HMIA showed a good mass spectrometric signal in negative electrospray ionization mode. In the new method, the nosiheptide residue in muscle tissue was hydrolyzed with sodium hydroxide aqueous solution; this was followed by cleanup using mixed mode cartridges. Identification and quantification of nosiheptide were carried out by analyzing HMIA in hydrolysate of muscles. Nosiheptide showed a good linear relationship (r > 0.996) in the calibration range of 2-500 µg/kg, and a low limit of quantification of 2 µg/kg was obtained in swine, chicken, and fish muscles. Recoveries of nosiheptide from spiked muscle samples were 85-108% with relative standard deviations less than 10%. The proposed method was successfully applied for the detection of the nosiheptide residue in medicated animal tissues samples.


Assuntos
Antibacterianos/química , Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/química , Contaminação de Alimentos/análise , Carne/análise , Espectrometria de Massas em Tandem/métodos , Álcalis/química , Animais , Galinhas , Peixes , Hidrólise , Limite de Detecção , Músculos/química , Suínos , Tiazóis/química
20.
Soft Matter ; 15(38): 7686-7694, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31498364

RESUMO

We report a simple and facile self-assembly approach to fabricate polyelectrolyte complex (PEC) hydrogel films with positively charged chitosan (CS) and negatively charged heparin sodium (HS) by combining hydrogen bonding and electrostatic interactions. The CS/HS hydrogel films exhibited excellent tensile strength and toughness, good self-recovery ability, superior water absorbency, and pH-dependent surface charge characteristics. The gelation mechanism was investigated by zeta potential measurements. The CS/HS hydrogel films exhibited high antibacterial efficacy against E. coli at selected pHs or when coordinated with various metal ions and a significant effect on accelerating wound healing. The self-assembly approach presented in this work may serve as a generic strategy for the fabrication of novel multi-functional PEC hydrogels for broad biomedical applications.


Assuntos
Antibacterianos/química , Quitosana/química , Heparina/química , Polieletrólitos/química , Cicatrização/efeitos dos fármacos , Antibacterianos/farmacologia , Cátions , Escherichia coli/efeitos dos fármacos , Humanos , Hidrogéis , Concentração de Íons de Hidrogênio , Membranas Artificiais , Metais/química , Pele , Propriedades de Superfície , Resistência à Tração , Água
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