Efficacy of the photon-induced photoacoustic streaming combined with nano-silver solution on Enterococcus faecalis in root canals / 口腔医学

Objective@#o explore the antibacterial effect of combined use of photon-induced photoacoustic streaming (PIPS) and silver nanoparticles (AgNPs) on Enterococcus faecalis biofilm in root canals.@*Methods@#A total of 36 isolated teeth with single root canal were collected to establish an experimental root canal model of Enterococcus faecalis infection. Samples were randomly divided into six groups and 0.9% NaCl, 2% NaClO, 0.1% AgNPs solutions were used with conventional needle irrigation (CNI) or PIPS for root canals. Colony count method was used to measure the number of Enterococcus faecalis biofilm in root canals before and after treatment, and the percentage of colony count reduction was calculated.@*Results@#The inhibitory effect of Enterococcus faecalis biofilm in all experimental groups was stronger than that in the control group (P<0.05). The decrease amplitude of 0.9% NaCl, 2% NaClO, 0.1% AgNPs assisted with PIPS was greater than that of 0.9% NaCl, 2% NaClO, 0.1% AgNPs assisted with CNI (P<0.05). The decrease in the 0.1% AgNPs assisted with PIPS group was significantly greater than that in the 2% NaClO assisted with PIPS group (P<0.05).@*Conclusion@#PIPS-assisted AgNPs solution washing can significantly improve the effect of clearing Enterococcus faecalis biofilm in root canals.

Mosquito larvicidal potential of Solanum xanthocarpum leaf extract derived silver nanoparticles and its bio-toxicity on non-target aquatic organism

Background & objectives: Mosquitoes are insects of public health importance that act as a vector to transmit various vector-borne diseases in humans including dengue, malaria, filariasis and yellow fever. The continually employed synthetic insecticides have developed resistance in mosquitoes. Nano-based botanical insecticides can be considered as the best alternative due to several advantages like being simple, non-pathogenic, biodegradable and safe to the environment. The present work reported the maximum larvicidal potential of green synthesized silver nanoparticles (AgNPs) derived from the leaf extract of Solanum xanthoearpum against the third instar larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus over its crude leaf extract. Methods: The synthesis of AgNPs was done by adding leaf extract into silver nitrate solution in a conical flask. The characterization of AgNPs was done using different techniques such as UV-Vis, SEM, TEM, XRD, DLS and SAED. FT-IR analysis was done to find out the compound responsible for bio-reduction of silver nitrate. Larvicidal activity of AgNPs was checked against An. stephensi, Ae. aegypti, and Cx. quinquefasciatus according to WHO standard protocol and toxicity was evaluated against Poecilia reticulate. Results: A change in colour was observed indicating the synthesis of AgNPs which was further confirmed by a strong surface plasmon resonance peak at 421nm under the UV-Vis spectrum. SEM and TEM micrographs exhibited that the most common shape of AgNPs was spherical. XRD spectrum showed crystalline nature of silver nanoparticles. FT-IR spectrum showed the presence of various functional groups such as carboxyl and hydroxyl which might be responsible for bio-reduction and capping of silver nanoparticles. Further, silver nanoparticles were very effective against An. stephensi, Ae. aegypti, and Cx. quinquefasciatus with LC50 and LC90 values of 1.90, 2.36, 2.93, 3.82, 4.31 and 7.63 ppm, respectively, as compared to aqueous leaf extract after 72 h of exposure and were non-toxic against non-target organism P. retieulata. Interpretation & eonelusion: From the above finding, it can be concluded that fabricated AgNPs can be promising eco-friendly tools for controlling mosquito vectors.

Exploiting the potential of bio-synthesized silver nanoparticles to enhance the shelf life of Gladiolus

Gladiolus spikes with fully turgid petals need to have a longer shelf life to fetch a higher price as well as display value. To improve the life duration of ornamental flowers, the ability of plants to produce silver nanoparticles (AgNP) was exploited. The ability of plants to produce AgNP when treated with silver nitrate solutions was juxtaposed by using Gladiolus (cut flowers): (i) To find the appropriate concentration of AgNO3 suitable for increasing shelf-life of Gladiolus cut flowers; (ii) To prepare silver nanoparticle from AgNO3; and (iii) To confirm the formation of silver nanoparticle using UV-vis spectrophotometry. Two different reductants (dehydrogenases present at the surface of the plant cells and sucrose) demonstrated the reduction of Ag+ to generate AgNPs. DLS (Dynamic Light Scattering) study revealed the presence of NPs in the AgNO3 salt solution incubated with Gladiolus cut flowers. The DLS data also suggested that the size of AgNPs decreased with increasing concentration of AgNO3. In the present study, along with silver nitrate, sucrose was also used. The shelf life and display value of the cut Gladiolus can be increased and optimized by incubating it in sucrose solution in combination with AgNO3.

Roots of Pennisetum sp. possess the competence to generate nanoparticles of noble metals

Roots of plants have immense reducing potential. Ions of noble metals namely Au3+ and Ag+ get reduced easily to form Au and Ag nanoparticles (NPs), respectively. Therefore, we hypothesize that plant roots could have potential to form Au-NPs and Ag-NPs. For present investigations, plants of Pennisetum glaucum L. were used to evaluate if their roots possess capacity to generate metal NPs. The generation of Au-NPs and Ag-NPs was initially presumed based on colour change, and confirmed by UV-vis spectra, TEM and EDX investigations. Pale yellow Au3+ and colourless Ag+ solutions turned purple and brown, respectively, by roots of Pennisetum sp. within 8 h. Absorption spectra of respective solutions showed plasmon resonance band at 560 nm and 420 nm confirming the presence of Au-NPs and Ag-NPs. TEM coupled with SAED revealed the presence of crystalline spherical NPs in the size range of 5-50 nm in these solutions. EDX further confirmed the presence of Au and Ag as NPs of respective solutions. These results confirmed that the roots of P. glaucum possess ideal reducing strength to generate Au-NPs and Ag-NPs exogenously in the aqueous phase.

In vitro antibacterial activities of silver nanoparticles synthesised using the seed extracts of three varieties of Phoenix dactylifera / Atividades antibacterianas in vitro de nanopartículas de prata sintetizadas usando extratos de sementes de três variedades de Phoenix dactylifera

Green synthesis of silver nanoparticles (AgNPs) is an ecofriendly, cost-effective and promising approach for discovery of novel therapeutics. The aim of the current work was to biogenic synthesize, characterize AgNPs using seed extracts of three economically important varieties of date palm (Iklas, Irziz and Shishi), and assess their anti-pathogenic bacterial activities. AgNPs were synthesised then characterised using electron microscopy and Fourier transform infrared analyses. The bactericidal activities of AgNPs against five different bacterial pathogens, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae, were determined in vitro. In particular, changes in membrane integrity of virulent bacterial strains in response to AgNPs were investigated. Results of lactate dehydrogenase, alkaline phosphatase activity assays, and measurement of membrane potential revealed that the cytotoxic effects of the AgNPs were mainly centred on the plasma membrane of bacterial cells, leading to loss of its integrity and eventually cell death. In conclusion, green synthesis of AgNPs is an efficient, cost-effective and promising strategy to combat virulent antibiotic-resistant strains.

A síntese verde de nanopartículas de prata (AgNPs) é uma abordagem ecologicamente correta, econômica e promissora para a descoberta de novas terapêuticas. O objetivo do presente trabalho foi sintetizar biogênica, caracterizar AgNPs usando extratos de sementes de três variedades economicamente importantes de tamareira (Iklas, Irziz e Shishi) e avaliar suas atividades bacterianas antipatogênicas. AgNPs foram sintetizados e caracterizados usando microscopia eletrônica e análise de infravermelho por transformada de Fourier. As atividades bactericidas de AgNPs contra cinco diferentes patógenos bacterianos, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus aureus resistente à meticilina e Streptococcus pneumoniae, foram determinadas in vitro. Em particular, foram investigadas alterações na integridade da membrana de cepas bacterianas virulentas em resposta a AgNPs. Os resultados da lactato desidrogenase, dos ensaios da atividade da fosfatase alcalina e da medição do potencial de membrana revelaram que os efeitos citotóxicos dos AgNPs estavam principalmente centrados na membrana plasmática das células bacterianas, levando à perda de sua integridade e, eventualmente, à morte celular. A síntese verde de AgNPs é uma estratégia eficiente, econômica e promissora para combater cepas virulentas resistentes a antibióticos.

In vitro antibacterial activities of silver nanoparticles synthesised using the seed extracts of three varieties of Phoenix dactylifera

Abstract Green synthesis of silver nanoparticles (AgNPs) is an ecofriendly, cost-effective and promising approach for discovery of novel therapeutics. The aim of the current work was to biogenic synthesize, characterize AgNPs using seed extracts of three economically important varieties of date palm (Iklas, Irziz and Shishi), and assess their anti-pathogenic bacterial activities. AgNPs were synthesised then characterised using electron microscopy and Fourier transform infrared analyses. The bactericidal activities of AgNPs against five different bacterial pathogens, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae, were determined in vitro. In particular, changes in membrane integrity of virulent bacterial strains in response to AgNPs were investigated. Results of lactate dehydrogenase, alkaline phosphatase activity assays, and measurement of membrane potential revealed that the cytotoxic effects of the AgNPs were mainly centred on the plasma membrane of bacterial cells, leading to loss of its integrity and eventually cell death. In conclusion, green synthesis of AgNPs is an efficient, cost-effective and promising strategy to combat virulent antibiotic-resistant strains.

Resumo A síntese verde de nanopartículas de prata (AgNPs) é uma abordagem ecologicamente correta, econômica e promissora para a descoberta de novas terapêuticas. O objetivo do presente trabalho foi sintetizar biogênica, caracterizar AgNPs usando extratos de sementes de três variedades economicamente importantes de tamareira (Iklas, Irziz e Shishi) e avaliar suas atividades bacterianas antipatogênicas. AgNPs foram sintetizados e caracterizados usando microscopia eletrônica e análise de infravermelho por transformada de Fourier. As atividades bactericidas de AgNPs contra cinco diferentes patógenos bacterianos, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus aureus resistente à meticilina e Streptococcus pneumoniae, foram determinadas in vitro. Em particular, foram investigadas alterações na integridade da membrana de cepas bacterianas virulentas em resposta a AgNPs. Os resultados da lactato desidrogenase, dos ensaios da atividade da fosfatase alcalina e da medição do potencial de membrana revelaram que os efeitos citotóxicos dos AgNPs estavam principalmente centrados na membrana plasmática das células bacterianas, levando à perda de sua integridade e, eventualmente, à morte celular. A síntese verde de AgNPs é uma estratégia eficiente, econômica e promissora para combater cepas virulentas resistentes a antibióticos.

In vitro antibacterial activities of silver nanoparticles synthesised using the seed extracts of three varieties of Phoenix dactylifera / Atividades antibacterianas in vitro de nanopartículas de prata sintetizadas usando extratos de sementes de três variedades de Phoenix dactylifera

Green synthesis of silver nanoparticles (AgNPs) is an ecofriendly, cost-effective and promising approach for discovery of novel therapeutics. The aim of the current work was to biogenic synthesize, characterize AgNPs using seed extracts of three economically important varieties of date palm (Iklas, Irziz and Shishi), and assess their anti-pathogenic bacterial activities. AgNPs were synthesised then characterised using electron microscopy and Fourier transform infrared analyses. The bactericidal activities of AgNPs against five different bacterial pathogens, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae, were determined in vitro. In particular, changes in membrane integrity of virulent bacterial strains in response to AgNPs were investigated. Results of lactate dehydrogenase, alkaline phosphatase activity assays, and measurement of membrane potential revealed that the cytotoxic effects of the AgNPs were mainly centred on the plasma membrane of bacterial cells, leading to loss of its integrity and eventually cell death. In conclusion, green synthesis of AgNPs is an efficient, cost-effective and promising strategy to combat virulent antibiotic-resistant strains.

A síntese verde de nanopartículas de prata (AgNPs) é uma abordagem ecologicamente correta, econômica e promissora para a descoberta de novas terapêuticas. O objetivo do presente trabalho foi sintetizar biogênica, caracterizar AgNPs usando extratos de sementes de três variedades economicamente importantes de tamareira (Iklas, Irziz e Shishi) e avaliar suas atividades bacterianas antipatogênicas. AgNPs foram sintetizados e caracterizados usando microscopia eletrônica e análise de infravermelho por transformada de Fourier. As atividades bactericidas de AgNPs contra cinco diferentes patógenos bacterianos, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus aureus resistente à meticilina e Streptococcus pneumoniae, foram determinadas in vitro. Em particular, foram investigadas alterações na integridade da membrana de cepas bacterianas virulentas em resposta a AgNPs. Os resultados da lactato desidrogenase, dos ensaios da atividade da fosfatase alcalina e da medição do potencial de membrana revelaram que os efeitos citotóxicos dos AgNPs estavam principalmente centrados na membrana plasmática das células bacterianas, levando à perda de sua integridade e, eventualmente, à morte celular. A síntese verde de AgNPs é uma estratégia eficiente, econômica e promissora para combater cepas virulentas resistentes a antibióticos.

A dual-signal sensor for the analysis of parathion-methyl using silver nanoparticles modified with graphitic carbon nitride / 药物分析学报

A highly sensitive and selective method was developed for both UV-vis spectrophotometric and fluo-rimetric determination of organophosphorus pesticides(OPs).This method used silver nanoparticles(AgNPs)modified with graphitic carbon nitride(g-C3N4).The AgNPs reduced the fluorescence intensity of g-C3N4.Acetylthiocholine(ATCh)could be catalytically hydrolyzed by acetylcholinesterase(AChE)to form thiocholine,which induces aggregation of the AgNPs.This aggregation led to the recovery of the blue fluorescence of g-C3N4,with excitation/emission peaks at 310/460 nm.This fluorescence intensity could be reduced again in the presence of OPs because of the inhibitory effect of OPs on the activity of AChE.The degree of reduction was found to be proportional to the concentration of OPs,and the limit of fluorometric detection was 0.0324 μg/L(S/N = 3).In addition,the absorption of the g-C3N4/AgNPs at 390 nm decreased because of the aggregation of the AgNPs,but was recovered in presence of OPs because of the inhibition of enzyme activity by OPs.This method was successfully applied to the analysis of parathion-methyl in real samples.

Therapeutic Effect Of Silver Nanoparticles Against Diethyl Nitrosamin And Carbon Tettrachloride-Induced Hepatocellular Carcinoma In Rats

Objective: Hepatic cancer is known as primary liver cancer and hepatocellular carcinoma (HCC). Newly silver nanoparticles gained importance due to its advantages and multiple potential such as molecular imaging agent, antimicrobial, wound healing, anti-inflammatory and anticancer activity. The current study deals to assess therapeutic property silver nanoparticles (AgNPs) against diethylnitrosamine (DENA), and carbon tetrachloride (CCL4) induced hepatic cancer. Methods: Thirty male albino rats (200-250g) were distributed into four groups and hepatic cancer was induced with a single intraperitoneal dose of 200 mg/kg body weight of DENA. Two weeks later, animals received subcutaneous injections of CCl4 once a week in a dose of 3 ml/kg body weight for 6weeks. Serum biomarkers, antioxidants enzymes, inflammatory markers were evaluated to find the anti-proliferative potential of silver nanoparticles. Histological evaluation and microscopic reports were also done to document the results of the current work. Results: AgNPs significantly recover the serum marker enzymes of hepatic parameter AST, ALT, ALP, and total bilirubin and also decreased the levels of NO, IL-6 and TNF-α. Histopathological features also exhibited recovery of a hepatic architecture in cancer-induced rats. Moreover, the immunohistochemical investigation demonstrated that the levels of PCNA, and Caspase-3, which are hepatocarcinogenic markers, were significantly improved by AgNPs. Conclusion: These results concluded that AgNPs showed promising curing effects on hepatocellular ailments.

In-Vitro Antimicrobial Activity Of Biological Synthesized Silver Nanoparticles Using Stenotrophomonas Maltophilia Strain Ns-24 From Non-Rhizosphere Soil

Objective: The present goals of our study were biological synthesis, characterizations of silver nanoparticles, and evaluation of its antimicrobial activity against microbial pathogens like Escherichia coli, Enterococcus faecalis, Streptococcus pneumoniae and Staphylococcus aureus. Methods: The bacterial Strain NS-24 was isolated on nutrient agar medium and was selected for the synthesis of silver nanoparticles based on its gram-negative characteristics. The characterizations of silver nanoparticles were done by UV-Visible spectroscopy, Atomic Force Microscopy (AFM), High Resolution-Transmission Electron Microscopy (HR-TEM), Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDX), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Later, the molecular characterization of the Strain NS-24 was done by DNA extraction and 16S rRNA gene sequencing. Results: The UV-visible spectrophotometric observation of the Strain NS-24 supernatant and AgNO3 solution showed maximum absorbance at 423 nm. The AFM data confirmed that the particles were polydispersed and spherical in shape. Additionally, the FTIR analysis revealed the IR spectral band patterning and TEM analyzes showed the size of biological AgNPs was in the range of 12.56 nm to 27.32 nm, with an average of 18.06 nm in size. Further, the 16S rRNA gene sequencing revealed the identity of Strain NS-24 as Stenotrophomonas maltophilia. The antimicrobial activity of AgNPs was studied on different gram-negative and gram-positive bacterial strains like Escherichia coli (MTCC 40), Enterococcus faecalis (MTCC 6845), Streptococcus pneumoniae (MTCC 8874) and Staphylococcus aureus (MTCC 2825), which showed good inhibition of their growth at varying concentrations of AgNPs against all the pathogens. Conclusion: Our findings showed that the synthesized AgNPs from the isolated bacterium was small in size and had profound antibacterial activity against pathogenic micro-organisms.

Nanocomposite hydrogel-based biopolymer modified with silver nanoparticles as an antibacterial material for wound treatment

Authors report the synthesis of sodium alginate-polyvinyl alcohol-g-acrylamide (NaAlg-PVA-g-AAm) nanocompositehydrogels modified with silver nanoparticles (AgNPs) as an antibacterial agent. In this work, we used NaAlg isolateddirectly from brown algae and studied the effects of the NaAlg weight ratio and silver-ion concentration on the networkmatrix in the hydrogels via in situ polymerization. Successfully synthesized nanocomposites were characterized usingFourier transform infrared, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, andatomic absorption spectrometry. The best results were achieved with an average AgNPs size of approximately 20 nmallowing the AgNPs to be absorbed in the nanocomposite hydrogel matrix. Nanocomposite hydrogels displayed goodantibacterial activity against Escherichia coli and Staphylococcus aureus. The minimum inhibitory concentrations(MICs) of silver nitrate (AgNO3) for E. coli and S. aureus were 46.251 and 75.220 ppm, respectively. Conversely,the minimum bactericidal concentrations (MBCs) of AgNO3 for these bacteria were 185.004 and 300.880 ppm,respectively. The MBC/MIC ratio of the AgNO3 modified nanocomposite hydrogels was four for both bacteria. Theresults illustrated that the nanocomposite hydrogels had good antibacterial activity against Gram-positive and Gramnegative bacteria and can be suitable for applications in wound treatments.

Synthesis and Characterization of Silver Nanoparticles from Ethanolic Extracts of Leaves of Annona muricata: A Green Nanobiotechnology Approach

Introduction: The biological green synthesis of nanoparticles via nanobiotechnology processes have a significant potential to boost nanoparticles production without the use of harsh, toxic, and expensive chemicals commonly used in conventional physical and chemical processes. Annona muricata, a tropical plant belonging to family Annonaceae is one of the most used plants in folk medicine because of its many medicinal uses and therefore presents a strong candidate for use in green synthesis. Aims: The aim of this study was to optimize a method for the synthesis of Silver Nanoparticles (AgNPs) from ethanolic extracts of leaves of Annona muricata as well as to characterize the green synthesized AgNPs. Methodology: AgNPs were synthesized from Annona muricata leaves using AgNO3 solution. The AgNPs were characterized using spectroscopy and microscopy techniques. Results: The formed AgNPs had an absorption maximum at 429 nm using UV–Visible spectroscopy and were stable under different pH, temperature, and storage conditions. Fourier transform infrared analysis revealed the different functional groups responsible for the synthesis and stabilization of the AgNPs. Scanning electron microscopy analysis revealed a spherical nature of the synthesized AgNPs. Energy dispersive x-ray spectroscopy analysis showed presence of Ag, O, and Cl with Ag having the highest composition at 60%. X-Ray Diffraction and Dynamic Light Scattering revealed a crystalline nature of AgNPs with an average size of 87.36 nm and a polydispersity index of 0.16 respectively. Transmission Electron Microscopy analysis further confirmed the crystalline and spherical nature of the AgNPs. Conclusion: In this article, an efficient, eco-friendly and low-cost method for the synthesis and recovery of stable AgNPs using Annona muricata leaves ethanolic extracts as both a reducing and capping agent has been reported for the first time. The synthesized AgNPs could be promising candidates for many biomedical, clinical, engineering, and polymer applications.

Anti Bacterial Effect Of Silver Nanoparticle On Mrsa Isolates From Oral Infections

Aim of our study is to evaluate the antibacterial activity of silver Nano particle(Ag-NPs) against MRSA strains recovered from patients with oral infections Material and Methods:- Samples were collected from Patients attending department of oral and maxillofacial surgery, Jaipur dental college who were diagnosed with oral infections. The samples were subjected to culture and sensitivity and MRSA (Methicillin resistant Staphylococcus aureus) screening. MRSAstrains were treated with Ag-Nanoparticles to know the antibacterial affect Results:- Out of 146 samples, 26 specimens showed Methicillin-resistant S aureus (MRSA) The MIC and MBC values of Ag-NPs against MRSA strains were observed to be very low (i.e. in the range of 12.5-100 μg/ml), indicating very well bacteriostatic (represented by the MIC) and bactericidal activity (represented by MBC). Conclusion:- In recent years, there is increase in MRSA in oral and perioral samples with emergence of new resistant strains of MRSA. In our study we have seen Ag-NPs size 5-10nm has inhibited growth of Methicillin Resistant Staphylococcus aureus in vitro at nontoxic concentration, which makes it to use as anti-bacterial agent in oral infections

Pullulan-Stabilized Silver Nanoparticles -Their Synthesis, Characterization and Application as Bactericidal Agents.

A rapid method for Pullulan-stabilized silver nanoparticles (PuAgNPs) synthesis has been developed. Different concentrations of Pullulan and Silver nitrate and effects of reaction time, pH was used to investigate the synthesis of silver nanoparticles. The synthesized Pu-AgNPs were first screened and identified using surface plasmon peaks of UV–VIS spectroscopy. The research results indicated that the surface plasmon resonance peaks were observed between 410–460 nm wavelengths in UV-VIS spectroscopy studies. The morphology of the synthesized AgNPs proved a variation in spherical shape and polydispersed with an average size of 10-55 nm, using TEM. Further, five characteristic peaks confirmed the presence of elemental silver and the crystalline structure of silver nanoparticles from XRD analysis. From FTIR spectra, stretching vibrations of hydroxyl (OH), carbonyl (C=O) and C=C stretches exhibits the reduction and stabilization of AgNPs. Further, clear zones of inhibition (about 10-25 mm) against four bacterial pathogens obtained in the antibacterial studies for the synthesized PuAgNPs. The experimental results demonstrated that pullulan could be used as reducing and stabilizing agent for formation of AgNPs and can be used as redoubtable bactericidal agents.

Facile way for synthesis silver nanoparticles for obtaining antibacterial textile fabrics.

One pot synthesis of silver nanoparticles (AgNPs) with well-defined size using polyvinyl alcohol (PVA) as stabilizing agent and sodium borohydride (NaBH4) as reducing agent was successfully performed. Preparation of AgNPs was carried out under a variety of conditions including concentrations of AgNPs, PVA and NaBH4. UV-vis spectra and TEM images were employed to characterize AgNPs obtained under the said different conditions. Physical and mechanical properties of cotton/polyester fabric treated with the synthesized silver nanoparticles were measured. SEM and EDX were used to scanning and observe the morphology and elemental change pertaining to fabric surface. Antibacterial activity against E. coli (Gm –ve bacteria) and Staphylococcus aureus (Gm +ve bacteria) were successfully examined against the treated and untreated fabrics.

Honey mediated silver nanoparticles and their inhibitory effect on aflatoxins and ochratoxin A.

Silver nanoparticles (AgNPs) have potential antimicrobial activity against bacteria and fungi. The synthesis of AgNPs have been reported using several chemical and physical methods which are not friendly environment. Therefore, our technique has focused on the synthesis of AgNPs by natural compounds. The aim of this study has been to synthesis AgNPs by safe nontoxic method using Egyptian honey (EH) as reducing and capping agents and to investigate its ability to reduce the mycelial growth and the production of aflatoxins (AFs) and ochratoxin A (OTA) by Aspergillus flavus and Aspergillus ochraceus, respectively. AgNPs have been characterized by UV-Visible Spectrophotometer, Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FTIR), and Transmission Electron Microscope (TEM).The obtained results indicated that the synthesis of honey AgNPs depends on the concentration of bulk metal (AgNO3) used in the synthesis process. The TEM image has revealed the formation of spherical well dispersed AgNPs, while the main size of AgNPs detected by DSL is 9.9 nm. Our results have indicated that 3 mg -100 ml media of honey derived AgNPs have reduced the aflatoxin (AF) G1, G2, B1 andB2 production by A. parasiticus to 77.55, , 62.91, 58.76 and 66.56%, respectively and ochratoxin A (OTA) by A. ochraceus to 79.85 % with significantly inhibitory effect on mycelial growth. The percentage of reduction depends on the AgNPs concentration.

Physical, Mechanical and Antimicrobial Evaluations of Physically Crosslinked PVA/Chitosan Hydrogels Containing Nanoparticles.

Chitosan/montmorillonite (MMT) and Poly vinyl Alcohol (PVA) / Silver nanoparticles (AgNPs) nanocomposites were prepared and formed hydrogel membranes using freeze thawing technique. The properties of the prepared hydrogels were investigated and compared to hydrogel membranes in presence and absence of nanometals. The physical behavior, mechanical properties and antibacterial activity was examined. Also the surface morphology monitored using scanning electron microscope. Antimicrobial activity against bacteria and yeast was also examined. The obtained results showed positive effect of nanometals especially AgNPs on swelling percent on the other hand tensile strength were combined by presence of MMT nanoparticles. The surface morphology showed homogenous images for all samples except samples containing MMT. All prepared samples containing nanoparticles showed antibacterial activity especially hydrogel membranes containing AgNPs.

Anti-biofilm efficacy of silver nanoparticles against MRSA and MRSE isolated from wounds in a tertiary care hospital.

Purpose: Different approaches have been used for preventing biofi lm-related infections in health care settings. Many of these methods have their own de-merits, which include chemical-based complications; emergent antibiotic resistant strains, etc. The formation of biofi lm is the hallmark characteristic of Staphylococcus aureus and S. epidermidis infection, which consists of multiple layers of bacteria encased within an exopolysachharide glycocalyx. Nanotechnology may provide the answer to penetrate such biofi lms and reduce biofi lm formation. Therefore, the aim of present study was to demonstrate the biofi lm formation by methicillin resistance S. aureus (MRSA) and methicillin resistance S. epidermidis (MRSE) isolated from wounds by direct visualisation applying tissue culture plate, tube and Congo Red Agar methods. Materials and Methods: The anti-biofi lm activity of AgNPs was investigated by Congo Red, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) techniques. Results: The minimum inhibitory concentration (MIC) was found to be in the range of 11.25-45 μg/ml. The AgNPs coated surfaces effectively restricted biofi lm formation of the tested bacteria. Double fl uorescent staining (propidium iodide staining to detect bacterial cells and fl uorescein isothiocyanate concanavalin A (Con A-FITC) staining to detect the exopolysachharides matrix) technique using CLSM provides the visual evidence that AgNPs arrested the bacterial growth and prevent the glycocalyx formation. In our study, we could demonstrate the complete anti-biofi lm activity AgNPs at a concentration as low as 50 μg/ml. Conclusions: Our fi ndings suggested that AgNPs can be exploited towards the development of potential anti-bacterial coatings for various biomedical and environmental applications. In the near future, the AgNPs may play major role in the coating of medical devices and treatment of infections caused due to highly antibiotic resistant biofilm.

Biosynthesis of Silver Nanoparticles Using Callus Extract of Catharanthus roseus var. alba and Assessment of Its Antimicrobial Activity.

Objective: To express a cost efficacious and environment friendly method for the green synthesis of silver nanoparticles (AgNPs) from Catharanthus roseus var. alba (C. roseus var. alba) callus extract. Methodology: The aqueous solution of sliver nitrate containing Ag+ ions (1 mM) are integrating 100 μL of aqueous extract of callus of C. roseus var. alba and 10 mL of 1% w/v aqueous solution of polyethylene glycol 4000 to 90 mL. This was then alkalized with 0.1 NaOH (20 μL) and treated in a microwave oven (800 W) for 40 sec for the reduction of metal ion and the reaction takes place at room temperature (250C). The reduction of the Ag+ ions by aqueous callus extract of C. roseus var. alba in the solutions was monitored by UV–Visible spectrum and further characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM) and x-ray diffraction (XRD). Antibacterial activity was assessed on bacterial strain of Staphylococcus aureus and Pseudomonas aeruginosa (S. aureus and P. aeruginosa) by using the disc-diffusion assay method. Results: Characterization of AgNPs was done DLS, TEM and XRD methods. The Dynamic Light Scattering (DLS) showed the particle size distribution of the AgNPs synthesized from C. roseus var. alba callus extract was found 86.95 nm with polydispersity index (PDI) value of = 0.304. TEM images showed the formation of AgNPs with an average size of 10 nm to 20 nm. And the XRD analysis showed that the AgNPs were crystalline in nature with face-centered-cubic (FCC). For the assessment of antibacterial activity the concentration of AgNPs 25 μL, 50 μL, 100 μL and 150 μL were used against both the bacterial strain S. aureus and P. aeruginosa, the zone of inhibition found 4 mm, 7 mm, 16 mm and 23 mm as well as 5 mm, 9 mm, 19 mm and 26 mm respectively. Conclusions: Aseptically engendered callus of C. roseus var. alba demonstrates vigorous potential for synthesis of silver nanoparticles by rapid reduction of Ag+ to Ag. The biologically synthesized AgNPs showed more preponderant antibacterial effect against S. aureus and P. aeruginosa.

Antifungal Effects of Silver Nanoparticles (AgNPs) against Various Plant Pathogenic Fungi

This research is concerned with the fungicidal properties of nano-size silver colloidal solution used as an agent for antifungal treatment of various plant pathogens. We used WA-CV-WA13B, WA-AT-WB13R, and WA-PR-WB13R silver nanoparticles (AgNPs) at concentrations of 10, 25, 50, and 100 ppm. Eighteen different plant pathogenic fungi were treated with these AgNPs on potato dextrose agar (PDA), malt extract agar, and corn meal agar plates. We calculated fungal inhibition in order to evaluate the antifungal efficacy of silver nanoparticles against pathogens. The results indicated that AgNPs possess antifungal properties against these plant pathogens at various levels. Treatment with WA-CV-WB13R AgNPs resulted in maximum inhibition of most fungi. Results also showed that the most significant inhibition of plant pathogenic fungi was observed on PDA and 100 ppm of AgNPs.