Synthesis of anisotropic silver nanoparticles using novel strain, Bacillus flexus and its biomedical application.
01 Feb 2013-Colloids and Surfaces B: Biointerfaces (Colloids Surf B Biointerfaces)-Vol. 102, pp 232-237
TL;DR: It is suggested that biogenic synthesis of nanoparticles have wide-application in medicine and physical chemistry and it can produce with eco-friendly, easy downstream processing and rapid scale-up processing.
About: This article is published in Colloids and Surfaces B: Biointerfaces.The article was published on 2013-02-01. It has received 273 citations till now. The article focuses on the topics: Silver nanoparticle & Silver nitrate.
Citations
More filters
TL;DR: It has been demonstrated that Ag NPs arrest the growth and multiplication of many bacteria such as Bacillus cereus, Staphylococcus aureus, Citrobacter koseri, Salmonella typhii, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, Vibrio parahaemolyticus and fungus.
Abstract: Use of silver and silver salts is as old as human civilization but the fabrication of silver nanoparticles (Ag NPs) has only recently been recognized. They have been specifically used in agriculture and medicine as antibacterial, antifungal and antioxidants. It has been demonstrated that Ag NPs arrest the growth and multiplication of many bacteria such as Bacillus cereus, Staphylococcus aureus, Citrobacter koseri, Salmonella typhii, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, Vibrio parahaemolyticus and fungus Candida albicans by binding Ag/Ag+ with the biomolecules present in the microbial cells. It has been suggested that Ag NPs produce reactive oxygen species and free radicals which cause apoptosis leading to cell death preventing their replication. Since Ag NPs are smaller than the microorganisms, they diffuse into cell and rupture the cell wall which has been shown from SEM and TEM images of the suspension containing nanoparticles and pathogens. It has also been shown that smaller nanoparticles are more toxic than the bigger ones. Ag NPs are also used in packaging to prevent damage of food products by pathogens. The toxicity of Ag NPs is dependent on the size, concentration, pH of the medium and exposure time to pathogens.
766 citations
Cites background or methods from "Synthesis of anisotropic silver nan..."
...In a study, the highly antibacterial activity has been ascribed to the release of silver cation from Ag NPs [173]....
[...]
...Rapid synthesis of Ag NPs has been achieved by the interaction of a bacterial strain S-27, belonging to Bacillus flexus group and 1 mM AgNO3 in aqueous medium [173]....
[...]
TL;DR: Synthesized Ag-NPs exhibited strong antibacterial activity against multidrug-resistant bacteria (Escherichia coli and Bacillus cereus) as well as cytotoxic effects against both human breast and human colon cancer cell lines.
Abstract: Using aqueous cyanobacterial extracts in the synthesis of silver nanoparticle is looked as green, ecofriendly, low priced biotechnology that gives advancement over both chemical and physical methods. In the current study, an aqueous extract of Oscillatoria limnetica fresh biomass was used for the green synthesis of Ag-NPs, since O. limnetica extract plays a dual part in both reducing and stabilizing Oscillatoria-silver nanoparticles (O-AgNPs). The UV-Visible absorption spectrum, Fourier transforms infrared (FT-IR), transmission electron microscopy (TEM) and scanning electron microscope (SEM) were achieved for confirming and characterizing the biosynthesized O-AgNPs. TEM images detected the quasi-spherical Ag-NPs shape with diverse size ranged within 3.30–17.97 nm. FT-IR analysis demonstrated the presence of free amino groups in addition to sulfur containing amino acid derivatives acting as stabilizing agents as well as the presence of either sulfur or phosphorus functional groups which possibly attaches silver. In this study, synthesized Ag-NPs exhibited strong antibacterial activity against multidrug-resistant bacteria (Escherichia coli and Bacillus cereus) as well as cytotoxic effects against both human breast (MCF-7) cell line giving IC50 (6.147 µg/ml) and human colon cancer (HCT-116) cell line giving IC50 (5.369 µg/ml). Hemolytic activity of Ag-NPs was investigated and confirmed as being non- toxic to human RBCs in low concentrations.
407 citations
TL;DR: Recent advancements in synthesis techniques for silver, gold, copper, titanium, zinc oxide, and magnesium oxide nanomaterials and composites are reviewed, with a focus on the toxicity exhibited by nanommaterials of multidimensions.
Abstract: The era of antibiotic resistance is a cause of increasing concern as bacteria continue to develop adaptive countermeasures against current antibiotics at an alarming rate In recent years, studies have reported nanoparticles as a promising alternative to antibacterial reagents because of their exhibited antibacterial activity in several biomedical applications, including drug and gene delivery, tissue engineering, and imaging Moreover, nanomaterial research has led to reports of a possible relationship between the morphological characteristics of a nanomaterial and the magnitude of its delivered toxicity However, conventional synthesis of nanoparticles requires harsh chemicals and costly energy consumption Additionally, the exact relationship between toxicity and morphology of nanomaterials has not been well established Here, we review the recent advancements in synthesis techniques for silver, gold, copper, titanium, zinc oxide, and magnesium oxide nanomaterials and composites, with a focus on the toxicity exhibited by nanomaterials of multidimensions This article highlights the benefits of selecting each material or metal-based composite for certain applications while also addressing possible setbacks and the toxic effects of the nanomaterials on the environment
380 citations
TL;DR: In this article, the authors investigated the in vitro cytotoxicity effect of biogenic silver nanoparticles (AgNPs) against human breast cancer (MCF-7) cells towards the development of anticancer agent.
351 citations
TL;DR: The aim of this review is to make a reflection on the current state and future prospects and especially the possibilities and limitations of the bio-based technique for industries.
Abstract: Microbial metal reduction can be a strategy for remediation of metal contaminations and wastes. Bacteria are capable of mobilization and immobilization of metals and in some cases, the bacteria which can reduce metal ions show the ability to precipitate metals at nanometer scale. Biosynthesis of nanoparticles (NPs) using bacteria has emerged as rapidly developing research area in green nanotechnology across the globe with various biological entities being employed in synthesis of NPs constantly forming an impute alternative for conventional chemical and physical methods. Optimization of the processes can result in synthesis of NPs with desired morphologies and controlled sizes, fast and clean. The aim of this review is, therefore, to make a reflection on the current state and future prospects and especially the possibilities and limitations of the above mentioned bio-based technique for industries.
326 citations
Cites background from "Synthesis of anisotropic silver nan..."
...These NPs showed efficacy on antibacterial property against clinically isolatedmultidrug resistant (MDR)microorganisms [61]....
[...]
References
More filters
TL;DR: These nontoxic nanomaterials, which can be prepared in a simple and cost-effective manner, may be suitable for the formulation of new types of bactericidal materials.
5,309 citations
TL;DR: Known mechanisms of microbial resistance (both intrinsic and acquired) to biocides are reviewed, with emphasis on the clinical implications of these reports.
Abstract: Antiseptics and disinfectants are extensively used in hospitals and other health care settings for a variety of topical and hard-surface applications A wide variety of active chemical agents (biocides) are found in these products, many of which have been used for hundreds of years, including alcohols, phenols, iodine, and chlorine Most of these active agents demonstrate broad-spectrum antimicrobial activity; however, little is known about the mode of action of these agents in comparison to antibiotics This review considers what is known about the mode of action and spectrum of activity of antiseptics and disinfectants The widespread use of these products has prompted some speculation on the development of microbial resistance, in particular whether antibiotic resistance is induced by antiseptics or disinfectants Known mechanisms of microbial resistance (both intrinsic and acquired) to biocides are reviewed, with emphasis on the clinical implications of these reports
4,243 citations
TL;DR: In this article, a sundried biomass of Cinnamomum camphora leaf with aqueous silver or gold precursors at ambient temperature was used for simple synthesis of nanoparticles.
Abstract: The synthesis of nanocrystals is in the limelight in modern nanotechnology. Biosynthesis of nanoparticles by plant extracts is currently under exploitation. Not only could silver nanoparticles ranging from 55 to 80 nm in size be fabricated, but also triangular or spherical shaped gold nanoparticles could be easily modulated by reacting the novel sundried biomass of Cinnamomum camphora leaf with aqueous silver or gold precursors at ambient temperature. The marked difference of shape control between gold and silver nanoparticles was attributed to the comparative advantage of protective biomolecules and reductive biomolecules. The polyol components and the water-soluble heterocyclic components were mainly responsible for the reduction of silver ions or chloroaurate ions and the stabilization of the nanoparticles, respectively. The sundried leaf in this work was very suitable for simple synthesis of nanoparticles.
1,614 citations
TL;DR: It is shown that plasmonic nanostructures of silver can concurrently use low-intensity visible light and thermal energy to drive catalytic oxidation reactions--such as ethylene epoxidation, CO oxidation, and NH₃ oxidation--at lower temperatures than their conventional counterparts that use only thermal stimulus.
Abstract: Catalysis plays a critical role in chemical conversion, energy production and pollution mitigation. High activation barriers associated with rate-limiting elementary steps require most commercial heterogeneous catalytic reactions to be run at relatively high temperatures, which compromises energy efficiency and the long-term stability of the catalyst. Here we show that plasmonic nanostructures of silver can concurrently use low-intensity visible light (on the order of solar intensity) and thermal energy to drive catalytic oxidation reactions--such as ethylene epoxidation, CO oxidation, and NH₃ oxidation--at lower temperatures than their conventional counterparts that use only thermal stimulus. Based on kinetic isotope experiments and density functional calculations, we postulate that excited plasmons on the silver surface act to populate O₂ antibonding orbitals and so form a transient negative-ion state, which thereby facilitates the rate-limiting O₂-dissociation reaction. The results could assist the design of catalytic processes that are more energy efficient and robust than current processes.
1,610 citations
TL;DR: The antibacterial effect of silver nanoparticles used in this study was found to be far more potent than that described in the earlier reports and was more pronounced against gram-negative bacteria than gram-positive organisms.
Abstract: In the present study, we report the preparation of silver nanoparticles in the range of 10‐15 nm with increased stability and enhanced anti-bacterial potency. The morphology of the nanoparticles was characterized by transmission electron microscopy. The antibacterial effect of silver nanoparticles used in this study was found to be far more potent than that described in the earlier reports. This effect was dose dependent and was more pronounced against gram-negative bacteria than gram-positive organisms. Although bacterial cell lysis could be one of the reasons for the observed antibacterial property, nanoparticles also modulated the phosphotyrosine profile of putative bacterial peptides, which could thus affect bacterial signal transduction and inhibit the growth of the organisms.
1,507 citations