Rational Design of Ag/ZnO Hybrid Nanoparticles on Sericin/Agarose Composite Film for Enhanced Antimicrobial Applications

Silver-based hybrid nanomaterials are receiving increasing attention as potential alternatives for traditional antimicrobial agents. Here, we proposed a simple and eco-friendly strategy to efficiently assemble zinc oxide nanoparticles (ZnO) and silver nanoparticles (AgNPs) on sericin-agarose composite film to impart superior antimicrobial activity. Based on a layer-by-layer self-assembly strategy, AgNPs and ZnO were immobilized on sericin-agarose films using the adhesion property of polydopamine. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray powder diffraction spectroscopy were used to show the morphology of AgNPs and ZnO on the surface of the composite film and analyze the composition and structure of AgNPs and ZnO, respectively. Water contact angle, swelling ratio, and mechanical property were determined to characterize the hydrophilicity, water absorption ability, and mechanical properties of the composite films. In addition, the antibacterial activity of the composite film was evaluated against Gram-positive and Gram-negative bacteria. The results showed that the composite film not only has desirable hydrophilicity, high water absorption ability, and favorable mechanical properties but also exhibits excellent antimicrobial activity against both Gram-positive and Gram-negative bacteria. It has shown great potential as a novel antimicrobial biomaterial for wound dressing, artificial skin, and tissue engineering.     

Ag NPs改性鱼鳞明胶-琼脂复合膜的制备及性能表征

利用鱼鳞明胶作为还原剂和稳定剂制备银纳米颗粒（silver nanoparticles, Ag NPs），研究Ag NPs添加量（0.04wt%-0.2wt%）对鱼鳞明胶-琼脂复合膜的理化性能和抗菌性能的影响。通过透射电子显微镜和X射线粉末衍射对合成的Ag NPs进行表征，结果表明制得Ag NPs为球形形貌，平均粒径为9.3 ?1.8 nm。随着Ag NPs添加量的增加，鱼鳞明胶-琼脂复合膜的色泽变黄渐深，透明度下降，对紫外和可见光的吸收增强，同时，复合膜的断裂延展性、水蒸气阻隔性能和耐水性能显著增强，而厚度和抗拉强度却无明显变化。FTIR和热重分析结果表明，Ag NPs与膜基质间存在化学相互作用，并在一定程度上改善了复合膜的热稳定性。抑菌环实验结果显示，复合膜可以在0.04wt%-0.2wt%较低的银浓度下实现良好的抗菌效果。研究结果将为鱼鳞明胶可降解抗菌包装材料的开发提供新思路。     

Mussel-inspired synthesis of silver nanoparticles as fillers for preparing waterborne polyurethane/Ag nanocomposites with excellent mechanical and antibacterial properties

Silver nanoparticles (AgNPs) were synthesized by a facile, mild and green method using dopamine as a reducing and stabilizing agent and were introduced to waterborne polyurethane (WPU) via an in situ emulsification method to prepare antibacterial nanocomposite films. The formation of AgNPs was characterized by UV–visible spectroscopy and XRD. The dispersion of AgNPs was confirmed by TEM and the thermal stability of WPU/Ag nanocomposites was confirmed by TGA. The results showed that AgNPs were uniformly dispersed in the WPU matrix. The introduction of AgNPs significantly improved the thermal stability of WPU films. With incorporation of 0.1 wt% AgNPs, a five-fold increase in the tensile strength was achieved without sacrificing the ultimate strain. The WPU/Ag nanocomposite films showed antibacterial activity against Escherichia coli and Staphylococcus aureus. © 2021 Society of Industrial Chemistry.     

基于植物质还原的银纳米颗粒的制备及在织物抗菌整理上的应用

纳米银是以纳米技术为基础研制而成的新型抗菌产品,由于量子效应和尺寸效应具有普通银系抗菌剂无法比拟的抗菌效果。本研究以黄芩、丁香、洋浦桃、芳樟4种植物质提取液制备银纳米颗粒,并借助于UV-Vis、TEM以及XRD对产物进行表征,结果表明增加植物质提取液浓度或增大NaOH加入量,均有利于制得粒径较小的银纳米颗粒。SEM图片表明采用浸渍法可将所得纳米银颗粒负载于纯棉织物上,通过考察浸渍时间、温度、浴比对织物上载银量的影响,确定较优的浸渍条件为时间30 h,温度55℃,浴比为1:25。分别考察了银纳米颗粒粒径和植物质种类对所得载银织物抗菌性能的影响,发现负载到织物上的纳米银粒径越小,织物抑菌效果越好;利用本身具有抑菌效果的黄芩、丁香来制备银纳米颗粒,有利于增强所得载银织物的整体抗菌性能;4种植物质中以黄芩制得的载银织物抗菌效果最优,对金黄色葡萄球菌、大肠杆菌等实验菌株均有强烈的抑制作用。     

无患子提取液制备纳米银及其协同抗菌性研究

以无患子提取液为还原剂,制备了含有纳米银的无患子复合抗菌液,考察了无患子提取液用量、温度、硝酸银摩尔浓度等因素对纳米银形貌和粒径的影响,并借助UV-Vis可见分光光谱、X射线衍射(XRD)以及透射电子显微镜(TEM)对产物进行表征;通过抑菌环法探讨了复合抗菌液对大肠杆菌的抗菌活性。由UV-Vis图谱可知,复合抗菌液等离子体共振吸收峰(SPR)在418 nm左右,说明该复合抗菌液中有纳米银的存在;XRD图表明合成的纳米银为面心立方结构;TEM图表明合成纳米银粒径为10~40 nm。由此获得的含有纳米银的无患子复合抗菌液对大肠杆菌表现出显著协同抗菌活性,抑菌圈直径变大。     

Study on antibacterial activity of silver nanoparticles synthesized by gamma irradiation method using different stabilizers

Colloidal solutions of silver nanoparticles (AgNPs) were synthesized by gamma Co-60 irradiation using different stabilizers, namely polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), alginate, and sericin. The particle size measured from TEM images was 4.3, 6.1, 7.6, and 10.2 nm for AgNPs/PVP, AgNPs/PVA, AgNPs/alginate, and AgNPs/sericin, respectively. The influence of different stabilizers on the antibacterial activity of AgNPs was investigated. Results showed that AgNPs/alginate exhibited the highest antibacterial activity against Escherichia coli (E. coli) among the as-synthesized AgNPs. Handwash solution has been prepared using Na lauryl sulfate as surfactant, hydroxyethyl cellulose as binder, and 15 mg/L of AgNPs/alginate as antimicrobial agent. The obtained results on the antibacterial test of handwash for the dilution to 3 mg AgNPs/L showed that the antibacterial efficiency against E. coli was of 74.6%, 89.8%, and 99.0% for the contacted time of 1, 3, and 5 min, respectively. Thus, due to the biocompatibility of alginate extracted from seaweed and highly antimicrobial activity of AgNPs synthesized by gamma Co-60 irradiation, AgNPs/alginate is promising to use as an antimicrobial agent in biomedicine, cosmetic, and in other fields.     

The use of polyethyleneimine-modified reduced graphene oxide as a substrate for silver nanoparticles to produce a material with lower cytotoxicity and long-term antibacterial activity

In order to improve the stability and decrease the cytotoxicity of silver nanoparticle (AgNP), a polyethyleneimine-modified reduced graphene oxide (PEI-rGO) was used as the substrate of AgNPs, and a PEI-rGO–AgNP hybrid was prepared by anchoring the AgNPs on the reduced graphene oxide surface. Such a hybrid showed substantially higher antibacterial activity than polyvinyl pyrrolidone (PVP)-stabilized AgNP, and the AgNPs on PEI-rGO were more stable than the AgNPs on PVP, resulting in long-term antibacterial effects. The hybrid showed excellent water-solubility and lower cytotoxicity, suggesting the great potential application as a sprayable graphene-based antibacterial solution.     

Silver-doped biphasic calcium phosphate/alginate microclusters with antibacterial property and controlled doxorubicin delivery

Biphasic calcium phosphate (BCP) based materials possessed with both excellent biocompatibility and antibacterial activity show potential advantages for biomedical applications. Here, the silver-doped BCP/Alginate (_AgBA) microclusters were first fabricated using the double-emulsions method. First, BCP nanoparticles were incorporated into the alginate network to form BCP/Alginate microclusters via the emulsion process. Then, silver nanoparticles (AgNPs) were in situ involved in BCP/Alginate networks to obtain the final _AgBA microclusters. Transmission electron microscopy and scanning electron microscopy confirmed that BCP nanoparticles and AgNPs were uniformly distributed in _AgBA microclusters. The morphology of _AgBA microclusters could be regulated by adjusting emulsion power, and microclusters using the medium powder (500 W) showed a regular spherical shape. Furthermore, CCK-8 analysis identified that _AgBA microclusters were cytocompatible culturing with human bone marrow-derived mesenchymal stem cells. Qualitative antibacterial tests exhibited the excellent inhibition effects of _AgBA microclusters against Staphylococcus aureus (Gram-positive) and Escherichia coli. (Gram-negative). Lastly, the doxorubicin (DOX)-loaded _AgBA microclusters presented adjustable loading efficiency of DOX and controllable release profiles. The cumulative release could reach 73.3% after 72 h in PBS. The above results raised a new route for antibacterial microclusters development for biomedical applications.     

Construction of Silver Nanoparticle-Loaded Micelles Via Coordinate Interaction and Their Antibacterial Activity

Silver nanoparticles (AgNPs) loaded antibacterial micelles were fabricated utilizing the coordinate interaction between silver ion (Ag⁺) and methoxy-poly(ethylene glycol)-block-poly(acrylamide-co-acrylonitrile) followed by in situ reduction. This micelle was characterized by X-ray photoelectron spectroscopy, transmission electron microscopy, and dynamic light scattering. The upper critical solution temperature of Ag⁺-loaded micelles was dependent on Ag⁺ concentration. The AgNPs were approximately 4 nm in diameter and homogenously distributed in the micelles. The AgNPs-loaded micelle displayed high stability during a one week study and excellent antibacterial activity against gram-negative Escherichia coli and was of acceptable toxicity toward human embryonic hepatocytes.     

Effects of ZnO nanoparticles on the mechanical and antibacterial properties of polyurethane coatings

Polyurethane-based coatings reinforced by ZnO nanoparticles (about 27 nm) were prepared via solution blending. The ZnO/PU films and coats were fabricated by a simple method of solution casting and evaporation. The mechanical properties of the films were investigated by a universal material test, and the abrasion resistance of the prepared coats was evaluated by a pencil-abrasion-resistance tester. It was found that significant improvement of the PU films in Young’s modulus and tensile strength was achieved by incorporating ZnO nanoparticles up to 2.0 wt%, and that the abrasion resistance of the PU coats was greatly enhanced due to the addition of ZnO nanoparticles. Moreover, the antibacterial property test was carried out via the agar dilution method and the result indicated that PU films doped with ZnO nanoparticles showed excellent antibacterial activity, especially for Escherichia coli.     

A comprehensive review of the polymer-based hydrogels with electrochemically synthesized silver nanoparticles for wound dressing applications

Modernization and improvement of wound dressing materials is an important topic in biomaterials and biomedicine fields, as the traditional materials are inadequate and susceptible to bacterial infections. In recent times, polymer-based hydrogel materials have presented themselves as excellent candidates for new-generation wound dressings with improved properties, such as high sorption ability, good mechanical properties, and low adhesiveness. Additionally, cross linked hydrogel matrices serve as excellent carriers for controlled release of antibacterial agents, such as silver nanoparticles (AgNPs), which are preferred over conventional antibiotics due to multi-phase mechanism of action and low susceptibility to induce bacterial resistance. Their incorporation inside polymer matrices allows improvement of wound dressing properties and sustained protection against bacterial infection. Electrochemical methods for AgNPs synthesis are facile and green alternatives to chemical routes, allowing the formation of highly stable AgNPs with strong antibacterial effect. In this article, we aim to provide a comprehensive review of the existing research on the topic of electrochemically synthesized silver nanoparticles incorporated in polymer matrices with a special focus on the chitosan-based hydrogels as prospective materials for wound dressing applications.     

Ageing behavior of acrylic polyurethane varnish coating in artificial weathering environments

Polyurethane-based coatings reinforced by ZnO nanoparticles (about 27 nm) were prepared via solution blending. The ZnO/PU films and coats were fabricated by a simple method of solution casting and evaporation. The mechanical properties of the films were investigated by a universal material test, and the abrasion resistance of the prepared coats was evaluated by a pencil-abrasion-resistance tester. It was found that significant improvement of the PU films in Young’s modulus and tensile strength was achieved by incorporating ZnO nanoparticles up to 2.0 wt%, and that the abrasion resistance of the PU coats was greatly enhanced due to the addition of ZnO nanoparticles. Moreover, the antibacterial property test was carried out via the agar dilution method and the result indicated that PU films doped with ZnO nanoparticles showed excellent antibacterial activity, especially for Escherichia coli.     

Enhanced antibacterial and anti-biofilm activities of silver nanoparticles against Gram-negative and Gram-positive bacteria

Silver nanoparticles (AgNPs) have been used as antibacterial, antifungal, antiviral, anti-inflammtory, and antiangiogenic due to its unique properties such as physical, chemical, and biological properties. The present study was aimed to investigate antibacterial and anti-biofilm activities of silver nanoparticles alone and in combination with conventional antibiotics against various human pathogenic bacteria. Here, we show that a simple, reliable, cost effective and green method for the synthesis of AgNPs by treating silver ions with leaf extract of Allophylus cobbe. The A. cobbe-mediated synthesis of AgNPs (AgNPs) was characterized by ultraviolet-visible absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Furthermore, the antibacterial and anti-biofilm activity of antibiotics or AgNPs, or combinations of AgNPs with an antibiotic was evaluated using a series of assays: such as in vitro killing assay, disc diffusion assay, biofilm inhibition, and reactive oxygen species generation in Pseudomonas aeruginosa, Shigella flexneri, Staphylococcus aureus, and Streptococcus pneumonia. The results suggest that, in combination with antibiotics, there were significant antimicrobial and anti-biofilm effects at lowest concentration of AgNPs using a novel plant extract of A. cobbe, otherwise sublethal concentrations of the antibiotics. The significant enhancing effects were observed for ampicillin and vancomycin against Gram-negative and Gram-positive bacteria, respectively. These data suggest that combining antibiotics and biogenic AgNPs can be used therapeutically for the treatment of infectious diseases caused by bacteria. This study presented evidence of antibacterial and anti-biofilm effects of A. cobbe-mediated synthesis of AgNPs and their enhanced capacity against various human pathogenic bacteria. These results suggest that AgNPs could be used as an adjuvant for the treatment of infectious diseases.     

Multicolor Layer-by-Layer films using weak polyelectrolyte assisted synthesis of silver nanoparticles

In the present study, we show that silver nanoparticles (AgNPs) with different shape, aggregation state and color (violet, green, orange) have been successfully incorporated into polyelectrolyte multilayer thin films using the layer-by-layer (LbL) assembly. In order to obtain colored thin films based on AgNPs is necessary to maintain the aggregation state of the nanoparticles, a non-trivial aspect in which this work is focused on. The use of Poly(acrylic acid, sodium salt) (PAA) as a protective agent of the AgNPs is the key element to preserve the aggregation state and makes possible the presence of similar aggregates (shape and size) within the LbLcolored films. This approach based on electrostatic interactions of the polymeric chains and the immobilization of AgNPs with different shape and size into the thin films opens up a new interesting perspective to fabricate multicolornanocomposites based on AgNPs.     

<Emphasis Type="Italic">Brassica rapa</Emphasis> var. <Emphasis Type="Italic">japonica</Emphasis> Leaf Extract Mediated Green Synthesis of Crystalline Silver Nanoparticles and Evaluation of Their Stability,Cytotoxicity and Antibacterial Activity

Silver nanoparticles (AgNPs) were successfully synthesized from the reduction of Ag⁺ using AgNO₃ solution as a precursor and Brassica rapa var. japonica leaf extract as a reducing and capping agent. This study was aimed at synthesis of AgNPs, exhibiting less toxicity with high antibacterial activity. The characterization of AgNPs was carried out using UV–Vis spectrometry, energy dispersive X-ray spectrometry, fourier transform infrared spectrometry, field emission scanning electron microscopy, X-ray diffraction, atomic absorption spectrometry, and transmission electron microscopy analyses. The analyses data revealed the successful synthesis of nano-crystalline Ag possessing more stability than commercial AgNPs. The cytotoxicity of Brassica AgNPs was compared with commercial AgNPs using in vitro PC12 cell model. Commercial AgNPs reduced cell viability to 23% (control 97%) and increased lactate dehydrogenase activity at a concentration of 3 ppm, whereas, Brassica AgNPs did not show any effects on both of the cytotoxicity parameters up to a concentration level of 10 ppm in PC12 cells. Moreover, Brassica AgNPs exhibited antibacterial activity in terms of zone of inhibition against E. coli (11.1?±?0.5 mm) and Enterobacter sp. (15?±?0.5 mm) which was higher than some previously reported green-synthesised AgNPs. Thus, this finding can be a matter of interest for the production and safe use of green-AgNPs in consumer products.     

Effect of plasma duty cycle on silver nanoparticles loading of cotton fabrics for durable antibacterial properties

A facile method for strongly anchoring silver nanoparticles (AgNPs) onto cotton fabrics was reported. It consists in loading AgNPs onto the cotton fiber preliminary coated with maleic anhydride plasma polymer layer. This results in hydrolyzis and ring opening of anhydride groups followed by electrovalent bonding of silver ions and reduction in NaBH₄. X‐ray photoelectron spectroscopy (XPS), infrared spectroscopy, and scanning electron microscope (SEM) were used to analyze changes in the surface chemical composition and morphology of the plasma modified fibers. The presence of AgNPs was confirmed by UV–Visible spectroscopy and atomic force microscopy (AFM) images. Remarkably, varying plasma duty cycle for plasma polymer deposition allowed tailoring the amount of loaded AgNPs. The highest amount of AgNPs was obtained with the lowest duty cycle values. Qualitative tests showed that silver containing plasma modified cotton displays significant antibacterial activity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41279.     

中草药还原法制备银纳米颗粒及其抗菌性能表征

分别以中草药丁香、山茱萸、地榆和乌梅的提取液为还原剂和保护剂合成银纳米颗粒,利用紫外-可见吸收光谱(UV-vis)、透射电镜(TEM)以及X射线粉末衍射(XRD)对产物进行了表征。结果表明,所得银纳米颗粒呈近球形,提高提取液的pH有利于获得粒径较小、分散性好、稳定性高的银纳米颗粒。进一步考察制得的银纳米颗粒的抗菌性能,结果表明,其对大肠杆菌和金黄色葡萄球菌有很强的抑制作用,最小抑菌质量浓度(M IC)分别可达1.69和3.38 mg/L。     

Facile modification of thin-film composite nanofiltration membrane with silver nanoparticles for anti-biofouling

This study focuses on the modification of a commercial nanofiltration (NF) membrane by an in-situ reaction to load silver nanoparticles (AgNPs) for anti-biofouling. Poly (vinyl alcohol) (PVA) was coated onto the NF membrane firstly, and silver salt was then deposited on the surface of PVA layer. Through thermal reduction, AgNPs with 10–20 nm in diameter were formed and immobilized onto the membrane surface by the interaction between AgNPs and PVA, as confirmed by UV–vis absorption spectrum, SEM and XPS analysis. Compared to the pristine NF90 membrane, the PVA composite membranes (NF90-PVA) and AgNPs (NF90-PVA-AgNPs) modified membranes exhibit lower water flux and slightly higher salt rejection. Release of silver ion experiments were assessed via batch method, and the results indicate silver ion can be released from the AgNPs modified membrane continuously and steadily, which may be responsible for the improved and long-time antibacterial ability of the membrane. Due to the simplicity of the method, the ability to immobilize the AgNPs to avoid leaching out, and the strong antibacterial activity, this NF90-PVA-AgNPs composite membrane displays potential applications in industrial water-treatment.     

AgNPs loaded microemulsion using gallic acid inhibits MCF-7 breast cancer cell line and solid ehrlich carcinoma

Abstract

The objective of this present work is to optimize and prepare silver nanoparticles(AgNPs) in Dioctyl sodium sulfosuccinate (AOT) microemulsion (ME) for oral use and to investigate its antibacterial and anticancer activity in vitro and in vivo. In vitro drug release study confirmed that faster release of drug at the tumor cells compared to the blood circulation. It also showed a potential antibacterial activity against pathogenic bacteria. The optimized AgNPs loaded ME confirmed significant cytotoxicity against MCF-7 cancer cell line with IC50 16.72?±?0.014?μg/mL and significant reduction in solid Ehrlich tumor growth in compared to the control, placebo and pure drug.     

Original antifouling strategy: Polypropylene films modified with chitosan-coated silver nanoparticles

A new coating strategy of polypropylene (PP) films with silver nanoparticles (AgNPs) is proposed to obtain surfaces with antifouling properties. As a first step, the photograft polymerization is used to produce polyacrylic acid-grafted PP (PAA-grafted PP) films. A green AgNP synthesis is used by thermal reduction of AgNO₃ with amino groups of chitosan (CS), which controls ion diffusion and stabilizes nanoparticles. AgNP/CS complexes are adsorbed on PAA-grafted PP by electrostatic interactions, yielding AgNP/CS-coated PP films. These films show an excellent antimicrobial activity, even for AgNP contents as low as 0.08 wt %, reducing more than 4 log units in the viable Staphylococcus aureus concentration or inducing Escherichia coli death. This trend is consistent with an adequate amount of small AgNP adsorbed in an organized manner within a thin surface layer. Therefore, the antimicrobial activity of this film seems to be more than promising, used as an active surface for a wide range of applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48448.