scholarly journals Modeling and Synthesis of Ag and Ag/Ni Allied Bimetallic Nanoparticles by Green Method: Optical and Biological Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Anuoluwa Abimbola Akinsiku ◽  
Enock Olugbenga Dare ◽  
Kolawole Oluseyi Ajanaku ◽  
Olayinka Oyewale Ajani ◽  
Joseph Adebisi O. Olugbuyiro ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Metallic Nanoparticles ◽  
Bimetallic Nanoparticles ◽  
Biological Properties ◽  
Optical Measurements ◽  
Ag Nps ◽  
Green Method ◽  
E Coli ◽  
Synthetic Routes ◽  
The Relationship

In the quest for environmental remediation which involves eco-friendly synthetic routes, we herein report synthesis and modeling of silver nanoparticles (Ag NPs) and silver/nickel allied bimetallic nanoparticles (Ag/Ni NPs) using plant-extract reduction method. Secondary metabolites in the leaf extract of Canna indica acted as reducing agent. Electronic transitions resulted in emergence of surface plasmon resonance in the regions of 416 nm (Ag NPs) and 421 nm (Ag/Ni NPs) during optical measurements. Further characterizations were done using TEM and EDX. Antimicrobial activity of the nanoparticles against clinical isolates was highly significant as P<0.05. These findings suggest application of Ag NPs as antibacterial agent against E. coli, S. pyogenes, and antifungal agent against C. albicans. Possible antibacterial drugs against S. pyogenes and E. coli can also be designed using Ag/Ni nanohybrid based on their strong inhibition activities. Similarly, the enhanced SPR in the nanoparticles is suggested for applications in optical materials, as good absorbers and scatters of visible light. Theoretical model clarified that the experiment observation on the relationship between metallic nanoparticles penetration through peptidoglycan layers and the activeness of microbial species depends on the nature of the nanoparticles and pore size of the layer.

scholarly journals Chitosan: An Overview of Its Properties and Applications

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3256
Author(s):  
Inmaculada Aranaz ◽  
Andrés R. Alcántara ◽  
Maria Concepción Civera ◽  
Concepción Arias ◽  
Begoña Elorza ◽  
...  
Keyword(s):  
Metallic Nanoparticles ◽  
Biological Properties ◽  
Technological Properties ◽  
Natural Origin ◽  
Technological Performance ◽  
Poor Solubility ◽  
Polymer Properties ◽  
Monomer Distribution ◽  
Number Of Publications ◽  
The Relationship

Chitosan has garnered much interest due to its properties and possible applications. Every year the number of publications and patents based on this polymer increase. Chitosan exhibits poor solubility in neutral and basic media, limiting its use in such conditions. Another serious obstacle is directly related to its natural origin. Chitosan is not a single polymer with a defined structure but a family of molecules with differences in their composition, size, and monomer distribution. These properties have a fundamental effect on the biological and technological performance of the polymer. Moreover, some of the biological properties claimed are discrete. In this review, we discuss how chitosan chemistry can solve the problems related to its poor solubility and can boost the polymer properties. We focus on some of the main biological properties of chitosan and the relationship with the physicochemical properties of the polymer. Then, we review two polymer applications related to green processes: the use of chitosan in the green synthesis of metallic nanoparticles and its use as support for biocatalysts. Finally, we briefly describe how making use of the technological properties of chitosan makes it possible to develop a variety of systems for drug delivery.

scholarly journals Biogenic Synthesis of Bi-Metallic (Zn-Cu) Nanoparticles by Leaf Extract of Citrus Limon and Evaluation of its Antibiofilm Activity Against E. coli

2021 ◽  
Vol 14 (4) ◽  
pp. 2017-2028
Author(s):  
Tooba Mazhar ◽  
Vikas Shrivastava ◽  
Rajesh Singh Tomar
Keyword(s):  
Metallic Nanoparticles ◽  
Bimetallic Nanoparticles ◽  
Average Particle Size ◽  
Antibacterial Properties ◽  
Colour Change ◽  
Antibiofilm Activity ◽  
Citrus Limon ◽  
Average Particle ◽  
Cu Nanoparticles ◽  
E Coli

The rapid hike in the usage of metallic as well as non-metallic nanoparticles demands their increased synthesis. In our study we synthesized bimetallic Zn-Cu nanoparticles using the greener route i.e. dry leaves powder of Citrus limon as it is environment-friendly, cost-effective, has a high surface area to volume ratio and hence superior over monometallic nanoparticles synthesized via physical or chemical approach. UTI is the most common nosocomial infection and the bacteria associated with it usually is E. coli. This pathogen forms biofilm and makes it difficult to treat the disease in less time. Hence, antimicrobial as well as antibiofilm activity of synthesized bimetallic nanoparticles was checked against E. coli. Our experimental procedure involved the preparation of ethanolic plant extract using dry leaf powder followed by synthesis of bimetallic nanoparticles. Particles were then characterized by using biophysical techniques such as FTIR, Powder-XRD and SEM-EDX. Next, we identified bacteria isolated from environment and hospital source and prepared their pure cultures. Lastly, we carried out the antibacterial and antibiofilm activity of synthesized nanoparticles against isolated E. coli. Particles showed the colour change from blue to green upon synthesis and were found to be a triclinic primitive type with an average particle size calculated to be 27.76nm as seen in PXRD. FTIR analysis gave characteristic peaks of functional groups. SEM-EDX confirmed successful doping and grain size of the particle. Bacteria isolated from samples showed pink rods in gram staining indicating gram-negative bacilli. Biochemical findings confirmed E. coli in samples. Characteristic zones of inhibition in range 12-18mm establish good antibacterial properties with MIC of synthesized nanoparticles <0.5mg/ml and crystal violet assay assure antibiofilm properties of Zn-Cu. The result of the study can be advantageous to develop an understanding of the development of nano-based medicine for biofilm-producing pathogens.

Green synthesis of mixed metallic nanoparticles using room temperature self-assembly

2017 ◽  
Vol 13 (2) ◽  
pp. 4671-4677 ◽  
Author(s):  
A. M. Abdelghany ◽  
A.H. Oraby ◽  
Awatif A Hindi ◽  
Doaa M El-Nagar ◽  
Fathia S Alhakami
Keyword(s):  
Self Assembly ◽  
Metallic Nanoparticles ◽  
Room Temperature ◽  
Bimetallic Nanoparticles ◽  
Reduction Process ◽  
Nano Particles ◽  
Nano Structure ◽  
Small Shift ◽  
Molar Ratios ◽  
Vis Spectroscopy

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure.

The relationship between health effects in triathletes and microbiological quality of freshwater

1995 ◽  
Vol 31 (5-6) ◽  
pp. 19-26 ◽  
Author(s):  
G. J. Medema ◽  
I. A. van Asperen ◽  
J. M. Klokman-Houweling ◽  
A. Nooitgedagt ◽  
M. J. W. van de Laar ◽  
...  
Keyword(s):  
Water Quality ◽  
Geometric Mean ◽  
Microbiological Quality ◽  
Quality Parameters ◽  
Health Complaints ◽  
E Coli ◽  
Thermotolerant Coliforms ◽  
Microbiological Water Quality ◽  
The Relationship ◽  
Faecal Streptococci

This pilot study was carried out to determine the relationship between microbiological water quality parameters and the occurrence of health complaints among triathletes. Data were collected at an Olympic distance triathlon (n=314) and a run-bike-run (n=81; controls for exposure to fresh water). At the time of the triathlon, the concentrations of Escherichia coli , thermotolerant coliforms, faecal streptococci, entero- and reoviruses, F-specific RNA phages, Salmonella, Campylobacter, Aeromonas, Plesiomonas shigelloides, Pseudomonas aeruginosa and Staphylococcus aureus were examined over the swimming course. Information on the occurrence of health complaints during the competition and in the week thereafter was collected through a written questionnaire. The results show that triathletes and run-bike-runners are comparable with respect to factors other than water exposure (age, sex, training history, physical stress, lower intestinal health complaints during the competition) that may influence the occurrence of health complaints in the week after the competition. Triathletes and run-bike-runners reported gastro-intestinal (7.7% vs 2.5%), respiratory (5.5% vs 3.7%), skin/mucosal (2.6% vs 1.2%), general (3.5% vs 1.2%) and total symptoms (14.8% vs 7.4%) in the week after the event. The health risks for triathletes for all symptom groups are not significantly higher than for run-bike-runners. The geometric mean concentration of faecal indicator bacteria is relatively low: E. coli 170/100 ml; faecal streptococci 13/100 ml, enteroviruses were present at concentrations of 0.1/l. The group of triathletes was homogeneusly and relatively intensely exposed to water; they all swam in the same body of water at the same time and 75% reported to have swallowed freshwater. It was concluded that this study design is suitable to study the relationship between health complaints and microbiological water quality. In the summers of 1993 and 1994, a study will be carried out concerning several run-bike-runs and triathlons in freshwaters of different quality.

The effect of type of water supply on water quality in a developing community in South Africa

1997 ◽  
Vol 35 (11-12) ◽  
pp. 35-40 ◽  
Author(s):  
B. Genthe ◽  
N. Strauss ◽  
J. Seager ◽  
C. Vundule ◽  
F. Maforah ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
E Coli ◽  
Guideline Values ◽  
Developing Communities ◽  
Quality Guideline ◽  
And Control ◽  
The Relationship

Efforts to provide water to developing communities in South Africa have resulted in various types of water supplies being used. This study examined the relationship between the type of water supply and the quality of water used. Source (communal taps, private outdoor and indoor taps) and point-of-use water samples were examined for heterotrophic plate counts (HPC), total and faecal coliforms, E. coli, and coliphages. Ten percent of samples were also analysed for enteric viruses, Giardia and Cryptosporidium. Approximately 320 households were included in a case-control study. In addition, a cross-sectional study was conducted. Both studies examined the relationship between different types of water facilities and diarrhoea among pre-school children. The source water was of good microbial quality, but water quality was found to have deteriorated significantly after handling and storage in both case and control households, exceeding drinking water quality guideline values by 1-6 orders of magnitude. Coliphage counts were low for all water samples tested. Enteric viruses and Cryptosporidium oocysts were not detected. Giardia cysts were detected on one occasion in case and control in-house samples. Comparisons of whether in-house water, after handling and storage, complied with water quality guideline values demonstrated households using communal taps to have significantly poorer quality than households using private outdoor or indoor taps for HPC and E. coli (χ2 = 14.9, P = 0.001; χ2 = 6.6, P = 0.04 respectively). A similar trend (although not statistically significant) was observed for the other microbial indicators. The cross-sectional study demonstrated an apparent decrease in health risk associated with private outdoor taps in comparison to communal taps. This study suggests that a private outdoor tap is the minimum level of water supply in order to ensure the supply of safe water to developing communities.

Potentials of Diphenyl Ether Scaffold as a Therapeutic Agent: A Review

2019 ◽  
Vol 19 (17) ◽  
pp. 1392-1406
Author(s):  
Suvarna G. Kini ◽  
Ekta Rathi ◽  
Avinash Kumar ◽  
Varadaraj Bhat
Keyword(s):  
Therapeutic Agent ◽  
Diphenyl Ether ◽  
Biological Properties ◽  
Industrial Applications ◽  
Synthetic Route ◽  
Structure Activity ◽  
Diphenyl Ethers ◽  
Antiviral Activities ◽  
Synthetic Routes ◽  
The 19Th Century

Diphenyl ethers (DPE) and its analogs have exhibited excellent potential for therapeutic and industrial applications. Since the 19th century, intensive research is perpetuating on the synthetic routes and biological properties of DPEs. Few well-known DPEs are Nimesulide, Fenclofenac, Triclosan, Sorafenib, MK-4965, and MK-1439 which have shown the potential of this moiety as a lead scaffold for different pharmacological properties. In this review, we recapitulate the diverse synthetic route of DPE moiety inclusive of merits and demerits over the classical synthetic route and how this moiety sparked an interest in researchers to discern the SAR (Structure Activity Relationship) for the development of diversified biological properties of DPEs such as antimicrobial, antifungal, antiinflammatory & antiviral activities.

Phyto-Facilitated Bimetallic ZnFe2O4 Nanoparticles via Boswellia carteri: Synthesis, Characterization and Anti-Cancer Activity.

2020 ◽  
Vol 21 ◽  
Author(s):  
Amer Imraish ◽  
Afnan Al-Hunaiti ◽  
Tuqa Abu-Thiab ◽  
Abed Al-Qader Ibrahim ◽  
Eman Hwaitat ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Cell Lines ◽  
Metallic Nanoparticles ◽  
Bimetallic Nanoparticles ◽  
Iron Chloride ◽  
Nano Particles ◽  
Adverse Side Effect ◽  
Wide Range ◽  
Anti Cancer ◽  
Znfe2o4 Nanoparticles

Background: The growing unsatisfaction toward the available traditional chemotherapeutic agents enhanced the need to develop new methods for obtaining materials with more effective and safe anti-cancer properties. Over the past few years, usage of metallic nanoparticles has been a target for researchers of different scientific and commercial fields due to their tiny sizes, environment friendly properties and wide range applications. To overcome the obstacles of traditional physical and chemical methods for synthesis of such nanoparticles, a new less expensive and eco-friendly method has been adopted using natural existing organisms as a reducing agent to mediate synthesis of the desired metallic nanoparticles from their precursors, a process called green biosynthesis of nanoparticles. Objective: Here in the present study, zinc iron bimetallic nanoparticles (ZnFe2O4) were synthesized via an aqueous extract of Boswellia Carteri resin mixed with zinc acetate and iron chloride precursors, and they were tested for their anticancer activity. Methods: Various analytic methods were applied for the characterization of the Phyto synthesized ZnFe2O4 and they were tested for their anticancer activity against MDA-MB-231, K562, MCF-7 cancer cell lines and normal fibroblasts. Results: Our results demonstrate the synthesis of cubic structured bimetallic nanoparticles ZnFe2O4 with an average diameter 10.54 nm. MTT cytotoxicity assay demonstrate that our phyto-synthesized ZnFe2O4 nanoparticles exhibited a selective and potent anticancer activity against K562 and MDA-MB-231 cell lines with IC50 values 4.53 µM and 4.19 µM, respectively. Conclusion: In conclusion, our bio synthesized ZnFe2O4 nano particles show a promising environmentally friendly of low coast chemotherapeutic approach against selective cancers with a predicted low adverse side effect toward normal cells. Further in vivo advanced animal research should be done to execute their applicability in living organisms.

Green synthesis of silver nanoparticles using sustainable resources and their use as antibacterial agents: A review

2020 ◽  
Vol 13 ◽  
Author(s):  
Kumari Jyoti ◽  
Punyasloka Pattnaik ◽  
Tej Singh
Keyword(s):  
Silver Nanoparticles ◽  
Plant Extracts ◽  
Metallic Nanoparticles ◽  
Cost Effective ◽  
Biological Properties ◽  
Metal Species ◽  
Sustainable Resources ◽  
Research Areas ◽  
Low Toxicity

Background:: Synthesis of metallic nanoparticles has attracted extensive vitality in numerous research areas such as drug delivery, biomedicine, catalysis etc. where continuous efforts are being made by scientists and engineers to investigate new dimensions for both technological and industrial advancements. Amongst numerous metallic nanoparticles, silver nanoparticle (AgNPs) is a novel metal species with low toxicity, higher stability and significant chemical, physical and biological properties. Methods:: In this, various methods for the fabrication of AgNPs are summarized. Importantly, we concentrated on the role of reducing agents of different plants parts, various working conditions such as AgNO3 concentration; ratio of AgNO3/extract; incubation time; centrifugal conditions, size and shapes. Results:: This study suggested that eco-friendly and non toxic biomolecules present in the extracts (e.g. leaf, stem and root) of plants are used as reducing and capping agents for silver nanoparticles fabrication. This method of fabrication of silver nanoparticles using plants extracts is comparatively cost-effective and simple. A silver salt is simply reduced by biomolecules present in the extracts of these plants. In this review, we have emphasized the synthesis and antibacterial potential of silver nanoparticles using various plant extracts. Conclusion:: Fabrication of silver nanoparticles using plant extracts have advantage over the other physical methods, as it is safe, eco-friendly and simple to use. Plants have huge potential for the fabrication of silver nanoparticles of wide potential of applications with desired shape and size.

scholarly journals Tocopherols and Tocotrienols—Bioactive Dietary Compounds; What Is Certain, What Is Doubt?

2021 ◽  
Vol 22 (12) ◽  
pp. 6222
Author(s):  
Kacper Szewczyk ◽  
Aleksandra Chojnacka ◽  
Magdalena Górnicka
Keyword(s):  
Vitamin E ◽  
Metabolic Disorders ◽  
Tissue Concentration ◽  
Biological Properties ◽  
Biological Role ◽  
Future Research ◽  
The Past ◽  
The Subject ◽  
The Relationship

Tocopherols and tocotrienols are natural compounds of plant origin, available in the nature. They are supplied in various amounts in a diet, mainly from vegetable oils, some oilseeds, and nuts. The main forms in the diet are α- and γ-tocopherol, due to the highest content in food products. Nevertheless, α-tocopherol is the main form of vitamin E with the highest tissue concentration. The α- forms of both tocopherols and tocotrienols are considered as the most metabolically active. Currently, research results indicate also a greater antioxidant potential of tocotrienols than tocopherols. Moreover, the biological role of vitamin E metabolites have received increasing interest. The aim of this review is to update the knowledge of tocopherol and tocotrienol bioactivity, with a particular focus on their bioavailability, distribution, and metabolism determinants in humans. Almost one hundred years after the start of research on α-tocopherol, its biological properties are still under investigation. For several decades, researchers’ interest in the biological importance of other forms of vitamin E has also been growing. Some of the functions, for instance the antioxidant functions of α- and γ-tocopherols, have been confirmed in humans, while others, such as the relationship with metabolic disorders, are still under investigation. Some studies, which analyzed the biological role and mechanisms of tocopherols and tocotrienols over the past few years described new and even unexpected cellular and molecular properties that will be the subject of future research.

scholarly journals Exploring the taxonomical and functional profile of As Burgas hot spring focusing on thermostable β-galactosidases

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
María-Eugenia DeCastro ◽  
Michael P. Doane ◽  
Elizabeth Ann Dinsdale ◽  
Esther Rodríguez-Belmonte ◽  
María-Isabel González-Siso
Keyword(s):  
Microbial Community ◽  
Hot Spring ◽  
Functional Characterization ◽  
Tca Cycle ◽  
Maximal Activity ◽  
Sulfur Cycle ◽  
E Coli ◽  
Complex Microbial Community ◽  
Relationship Of ◽  
The Relationship

AbstractIn the present study we investigate the microbial community inhabiting As Burgas geothermal spring, located in Ourense (Galicia, Spain). The approximately 23 Gbp of Illumina sequences generated for each replicate revealed a complex microbial community dominated by Bacteria in which Proteobacteria and Aquificae were the two prevalent phyla. An association between the two most prevalent genera, Thermus and Hydrogenobacter, was suggested by the relationship of their metabolism. The high relative abundance of sequences involved in the Calvin–Benson cycle and the reductive TCA cycle unveils the dominance of an autotrophic population. Important pathways from the nitrogen and sulfur cycle are potentially taking place in As Burgas hot spring. In the assembled reads, two complete ORFs matching GH2 beta-galactosidases were found. To assess their functional characterization, the two ORFs were cloned and overexpressed in E. coli. The pTsbg enzyme had activity towards o-Nitrophenyl-β-d-galactopyranoside (ONPG) and p-Nitrophenyl-β-d-fucopyranoside, with high thermal stability and showing maximal activity at 85 °C and pH 6, nevertheless the enzyme failed to hydrolyze lactose. The other enzyme, Tsbg, was unable to hydrolyze even ONPG or lactose. This finding highlights the challenge of finding novel active enzymes based only on their sequence.

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