scholarly journals Synthesis of Gold Nanobipyramids by Seed-mediated Method and Santibacterial Activities

2018 ◽  
Vol 28 (2) ◽  
pp. 179 ◽  
Author(s):  
Ngo Vo Ke Thanh ◽  
Huynh Trong Phat ◽  
Nguyen Thi Kim Anh ◽  
Nguyen Dang Giang ◽  
Lam Quang Vinh
Keyword(s):  
Silver Nanoparticles ◽  
Metallic Nanoparticles ◽  
Cetyltrimethylammonium Bromide ◽  
Antibacterial Agents ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Seed Mediated ◽  
Antibacterial Nanoparticles ◽  
Gold Nanobipyramids ◽  
And Staphylococcus Aureus

Metallic nanoparticles as antibacterial agents have been studied for several years. The most used antibacterial nanoparticles are silver nanoparticles. The mechanisms and  antibacterial properties of silver nanoparticles are well known, but the effects of gold nanoparticles, especially gold Nano bipyramids, are not considered. In this research, we synthesized gold nanobipyramids (NBPs) by seed mediated method using surfactant cetyltrimethylammonium bromide (CTAB). After preparing, gold nanobipyramids is removed CTAB and modified the surface using polyethylene glycol, polyvinyl alcohol and chitosan as the stabilizers. Besides, antibacterial effects of gold nanobipyramids on both Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) are investigated in this paper. The results show that gold nanobipyramids have good antibacterial activities even at low concentration. The optimal concentration of stabilizers and gold nanobipyramids in antibacterial activities are also studied in this paper.

scholarly journals Limitations of Recent Studies Dealing with the Antibacterial Properties of Silver Nanoparticles: Fact and Opinion

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1775 ◽  
Author(s):  
Raphaël E. Duval ◽  
Jimmy Gouyau ◽  
Emmanuel Lamouroux
Keyword(s):  
Silver Nanoparticles ◽  
Infectious Diseases ◽  
Metallic Nanoparticles ◽  
Bacterial Infections ◽  
Antibacterial Agents ◽  
Therapeutic Option ◽  
Antibacterial Properties ◽  
Antimicrobial Activities ◽  
Synthetic Process ◽  
Great Heterogeneity

Due to the constant increase in the number of infectious diseases and the concomitant lack of treatment available, metallic nanoparticles (e.g., silver nanoparticles) have been of particular interest in the last decades. Indeed, several studies suggest that silver nanoparticles have valuable antimicrobial activities, especially against bacteria, which may lead us to think that these nanoparticles may one day be an attractive therapeutic option for the treatment of bacterial infections. Unfortunately, when we look a little closer to these studies, we can see a very great heterogeneity (e.g., in the study design, in the synthetic process of nanoparticles, in the methods that explore the antibacterial properties of nanoparticles and in the bacteria chosen) making cross-interpretation between these studies impossible, and significantly limiting the interest of silver nanoparticles as promising antibacterial agents. We have selected forty-nine international publications published since 2015, and propose to discuss, not the results obtained, but precisely the different methodologies developed in these publications. Through this discussion, we highlighted the aspects to improve, or at least to homogenize, in order to definitively establish the interest of silver nanoparticles as valuable antibacterial agents.

scholarly journals Interaction of Silver Nanoparticles with Serum Proteins Affects Their Antimicrobial ActivityIn Vivo

2013 ◽  
Vol 57 (10) ◽  
pp. 4945-4955 ◽  
Author(s):  
Divya Prakash Gnanadhas ◽  
Midhun Ben Thomas ◽  
Rony Thomas ◽  
Ashok M. Raichur ◽  
Dipshikha Chakravortty
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Serum Albumin ◽  
Serum Proteins ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Resistant Bacteria ◽  
Human Society ◽  
Vis Spectroscopy

ABSTRACTThe emergence of multidrug-resistant bacteria is a global threat for human society. There exist recorded data that silver was used as an antimicrobial agent by the ancient Greeks and Romans during the 8th century. Silver nanoparticles (AgNPs) are of potential interest because of their effective antibacterial and antiviral activities, with minimal cytotoxic effects on the cells. However, very few reports have shown the usage of AgNPs for antibacterial therapyin vivo. In this study, we deciphered the importance of the chosen methods for synthesis and capping of AgNPs for their improved activityin vivo. The interaction of AgNPs with serum albumin has a significant effect on their antibacterial activity. It was observed that uncapped AgNPs exhibited no antibacterial activity in the presence of serum proteins, due to the interaction with bovine serum albumin (BSA), which was confirmed by UV-Vis spectroscopy. However, capped AgNPs [with citrate or poly(vinylpyrrolidone)] exhibited antibacterial properties due to minimized interactions with serum proteins. The damage in the bacterial membrane was assessed by flow cytometry, which also showed that only capped AgNPs exhibited antibacterial properties, even in the presence of BSA. In order to understand thein vivorelevance of the antibacterial activities of different AgNPs, a murine salmonellosis model was used. It was conclusively proved that AgNPs capped with citrate or PVP exhibited significant antibacterial activitiesin vivoagainstSalmonellainfection compared to uncapped AgNPs. These results clearly demonstrate the importance of capping agents and the synthesis method for AgNPs in their use as antimicrobial agents for therapeutic purposes.

scholarly journals Homogeneous Coatings of Titanium Dioxide Nanoparticles on Corona-Treated Cotton Fabric for Enhanced Self-Cleaning and Antibacterial Properties

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Mojtaba Aalipourmohammadi ◽  
Abolfazl Davodiroknabadi ◽  
Ali Nazari
Keyword(s):  
Titanium Dioxide ◽  
Pathogenic Bacteria ◽  
Titanium Dioxide Nanoparticles ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Sunlight Irradiation ◽  
Self Cleaning ◽  
Mapping Techniques ◽  
Cellulosic Fabric ◽  
And Staphylococcus Aureus

Abstract This study discusses the effect of corona pretreatment and subsequent loading of titanium dioxide nanoparticles on self-cleaning and antibacterial properties of cellulosic fabric. The corona-pretreated cellulosic fabrics were characterized by field emission scanning electron microscopy, and X-ray mapping techniques revealed that layers of the titania deposited on cellulose fibers were more uniform than the sample without pre-corona treatment. The self-cleaning property of treated fabrics was evaluated through discoloring dye stain under sunlight irradiation. The antibacterial activities of the samples against two common pathogenic bacteria including Escherichia coli and Staphylococcus aureus were also assessed. The results indicated that self-cleaning and antibacterial properties of the corona-pretreated fabrics were superior compared to the sample treated with TiO2 alone. Moreover, using corona pretreatment leads to samples with good washing fastness.

scholarly journals Study of Antibacterial Properties of Ziziphus mauritiana based Green Synthesized Silver Nanoparticles against Various Bacterial Strains

2020 ◽  
Vol 12 (4) ◽  
pp. 1484 ◽  
Author(s):  
M. Asimuddin ◽  
Mohammed Rafi Shaik ◽  
Neeshat Fathima ◽  
M. Shaistha Afreen ◽  
Syed Farooq Adil ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Metallic Nanoparticles ◽  
Low Cost ◽  
Preliminary Investigation ◽  
Antibacterial Properties ◽  
Silver Ions ◽  
Ziziphus Mauritiana ◽  
Bacterial Strains ◽  
Vis Spectroscopy ◽  
Ft Ir

Due to their low cost and environmentally friendly nature, plant extracts based methods have gained significant popularity among researchers for the synthesis of metallic nanoparticles. Herein, green synthesis of silver nanoparticles was performed using the aqueous solution of Ziziphus mauritiana leaves extract (ZM-LE) as a bio-reducing agent. The as-obtained silver nanoparticles were characterized by using UV-Vis spectroscopy, XRD (X-ray diffraction), TEM (transmission electron microscopy), and FT-IR (Fourier-transform infrared spectroscopy). In addition, the effects of the concentrations of the leaves extract, silver nitrate, and the temperature on the preparation of nanoparticles were also investigated. In order to determine the nature of secondary metabolites present in leaves extract, a preliminary investigation of phytoconstituents was carried out using different methods including Folin-Ciocalteu and AlCl3 methods. The results have indicated the presence of a considerable amount of phenolic and flavonoid contents in the leaves extract, which are believed to be responsible for the reduction of silver ions and stabilization of resulting nanoparticles. Indeed, the FT-IR spectrum of silver nanoparticles also confirmed the presence of residual phytomolecules of leaves extract as stabilizing ligands on the surface of nanoparticles. The antibacterial properties of as-obtained silver nanoparticles were tested against various bacterial strains including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis. The nanoparticles strongly inhibited the growth of S. aureus with a minimum inhibitory concentration (MIC) of 2.5 μg/ml and moderately inhibited the growth of E. coli with a MIC of 5 μg/ml.

Antibacterial properties of biosynthesized silver nano particles

2020 ◽  
Vol 4 (1) ◽  
pp. 1-5
Author(s):  
Krishna Reddy BV ◽  
Avinash Kumar G ◽  
Nageswara Rao G
Keyword(s):  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Large Scale ◽  
Leaf Extract ◽  
Antibacterial Agents ◽  
Uv Spectroscopy ◽  
Antibacterial Properties ◽  
Nano Particles ◽  
Lannea Coromandelica ◽  
Cost Efficacy

Nanoparticles have their demand in various fields of science and technology and their applications extend even in medical and pharmaceutical arena. They have been used as preservatives, diagnosing aids and potent antibacterial agents. But their production is a serious matter of concern when it comes to cost, efficacy and toxicity issues. Overcoming these limitations green synthesis has taken its advantage for their commercial and large scale synthesis. This research will focus on the preparation of nano particles of silver with the help of purified leaf extract from Lannea coromandelica and evaluation of the same using UV-Vis Spectrophotometry. The nanoparticles exhibited surface plasmon resonance at 420nm in UV spectroscopy. Futhermore, nanoparticles have been evaluated for their antibacterial activity on Putida vulgaris, Staphylococcus aureus, and Bacillus subtillis. The results proved the eco friendly synthesized silver nanoparticles have a good antibacterial and can be used effectively in therapies targeting infections and infectious wounds.

scholarly journals Green Synthesis of Silver Nanoparticles by Extracellular Extracts from Aspergillus japonicus PJ01

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4479
Author(s):  
Pei-Jun Li ◽  
Jiang-Juan Pan ◽  
Li-Jun Tao ◽  
Xia Li ◽  
Dong-Lin Su ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Antibacterial Activities ◽  
Synthesis Process ◽  
Biological Synthesis ◽  
X Ray Diffraction ◽  
Aspergillus Japonicus ◽  
Transmission Electron ◽  
Naoh Solution

The present study focuses on the biological synthesis, characterization, and antibacterial activities of silver nanoparticles (AgNPs) using extracellular extracts of Aspergillus japonicus PJ01.The optimal conditions of the synthesis process were: 10 mL of extracellular extracts, 1 mL of AgNO3 (0.8 mol/L), 4 mL of NaOH solution (1.5 mol/L), 30 °C, and a reaction time of 1 min. The characterizations of AgNPs were tested by UV-visible spectrophotometry, zeta potential, scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric (TG) analyses. Fourier transform infrared spectroscopy (FTIR) analysis showed that Ag+ was reduced by the extracellular extracts, which consisted chiefly of soluble proteins and reducing sugars. In this work, AgNO3 concentration played an important role in the physicochemical properties and antibacterial properties of AgNPs. Under the AgNO3 concentration of 0.2 and 0.8 mol/L, the diameters of AgNPs were 3.8 ± 1.1 and 9.1 ± 2.9 nm, respectively. In addition, smaller-sized AgNPs showed higher antimicrobial properties, and the minimum inhibitory concentration (MIC) values against both E. coli and S. aureus were 0.32 mg/mL.

scholarly journals Radiolytic Synthesis of Colloidal Silver Nanoparticles for Antibacterial Wound Dressings

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Pimpon Uttayarat ◽  
Jarurattana Eamsiri ◽  
Theeranan Tangthong ◽  
Phiriyatorn Suwanmala
Keyword(s):  
Silver Nanoparticles ◽  
Gamma Radiation ◽  
Metallic Nanoparticles ◽  
Antibacterial Properties ◽  
Wound Dressings ◽  
Poly Vinyl Alcohol ◽  
Metallic Silver ◽  
Colloidal Silver ◽  
Colloidal Silver Nanoparticles ◽  
Radiolytic Synthesis

Radiolytic synthesis provides a convenient and environmentally-friendly approach to prepare metallic nanoparticles in large scale with narrow size distribution. In this report, colloidal silver nanoparticles (AgNPs) were synthesized by gamma radiation using poly(vinyl alcohol) (PVA) or silk fibroin (SF) as stabilizers and were evaluated for their antibacterial properties. The conversion of metallic silver ions to silver atoms depended on irradiation dose and stabilizer concentration as determined by UV-Vis spectrophotometry and transmission electron microscopy. The uniformly dispersed AgNPs with diameter 32.3 ± 4.40 nm were evaluated as antiseptic agents in films composed of chitosan, SF, and PVA that were processed by irradiation-induced crosslinking. Using disc diffusion assay, the films containing 432 ppm AgNPs could effectively inhibit the growth of bothStaphylococcus aureusandPseudomonas aeruginosa. Therefore, we have demonstrated in our present study that gamma radiation technique can potentially be applied in the mass production of antibacterial wound dressings.

scholarly journals Biosynthesis and Characterization of Silver Nanoparticles From Pantoea agglomerans and Some of Their Antibacterial Activities

2020 ◽  
Vol 31 (3) ◽  
pp. 1
Author(s):  
Layla Abdul-Hamid Said
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Room Temperature ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Pantoea Agglomerans ◽  
Force Microscopy ◽  
Atomic Force ◽  
And Staphylococcus Aureus

Recently, the biosynthesis of nanoparticles from bacteria have attracted attention, this study has been made for biosynthesize and characterizes silver nanoparticles (AgNPs) from local clinical isolate Pantoea agglomerans. The ability of those particles to inhibit the virulence factors biofilm and hemolysin produced by some local clinical multidrug-resistant human pathogenes including Acinetobactor haemolyticus, Escherichia coli, Serratia marcescens and Staphylococcus aureus were investigated by treating all of the test isolates with sub-MIC(16 mg/ml) AgNPs. The AgNPs produced were characterized using Atomic Force Microscopy (AFM). Pantoea agglomerans were found to have the ability to synthesize AgNPs at room temperature within 24hrs and were spherical in shape as depicted by AFM. The AgNPs produced exhibited a potential antibiofilm and hemolysin inhibition activities against tested pathogens.

scholarly journals Enhancement of antibacterial properties of various polymers functionalized with silver nanoparticles

2019 ◽  
Vol 10 (3) ◽  
pp. 5592-5598
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Surface Morphology ◽  
Bacillus Cereus ◽  
Water Absorption ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Color Transformation ◽  
Green Procedure

A new green deposition of silver nanoparticles (AgNPs) on polymers was proposed in this work. In-situ synthesis of AgNPs on polymers was achieved via a green procedure using natural reducing agents, which are Ageratum conyzoidez and Mikania micrantha. Several characterizations of the treated polymers such as color transformation, surface morphology, elemental contents, and water absorption were comprehensively evaluated. For the application, the treated polymers were then tested against waterborne bacteria, which are Escherichia coli and Bacillus cereus. Rapid deposition of AgNPs via the presently biological method can be successfully achieved as observed via surface morphology analysis and energy dispersive X-ray investigation. Water absorption capabilities of the polymers can be decreased after attaching with AgNPs, which can also probably contribute to the enhancement of their antibacterial activities. This study observed that the treated polymers showed excellent antibacterial activities against Escherichia coli and Bacillus cereus. The findings of this study are useful in designing water purifiers to disinfect contaminated water.

scholarly journals Synthesis of antibacterial polyurethane film and its properties

2020 ◽  
Vol 22 (2) ◽  
pp. 50-55
Author(s):  
Zhao Lin ◽  
Li Yunyun ◽  
Cheng Bin ◽  
Chen Yu
Keyword(s):  
Mechanical Properties ◽  
Silver Nanoparticles ◽  
Composite Film ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Practical Applications ◽  
Polyurethane Film ◽  
Good Biocompatibility ◽  
Biomedical Field

AbstractPolyurethane (PU) is a polymer widely used in the biomedical field with excellent mechanical properties and good biocompatibility. However, it usually exhibits poor antibacterial properties for practical applications. Efforts are needed to improve the antibacterial activities of PU films for broader application prospect and added application values. In the present work, two PU films, TDI-P(E-co-T) and TDI-N-100-P(E-co-T), were prepared. Silver nanoparticles (AgNPs) were composited into the TDI-N-100-P(E-co-T) film for better mechanical properties and antibacterial activities, and resultant PU/AgNPs composite film was systematically characterized and studied. The as-prepared PU/AgNPs composite film exhibits much better antibacterial properties than the traditional PU membrane, exhibiting broader application prospect.

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