Ag Citrate Research Articles

Study of the properties of nanoparticles of Ag and Zn citrates

The use of nanomaterials has become especially relevant as components of new drugs, adjuvants and new ingredients in feed additives. The very combination of inorganic components (metals) with natural minerals (сeolites, clenoptolites) made it possible to create fundamentally new chemical compounds that differ significantly in the mechanism of action and their physicochemical characteristics from traditionally used drugs for the treatment of bacterial diseases of poultry. The practical application of the composition involves the use of small sizes of nanoparticles that are in the “nanoscale” from 1 to 100 nm. Our article contains the results of studies of Ag and Zn nanomaterials in combination with citrate in the form of powder and dispersed solutions. As a result of scanning electron microscopy, it was found that the studied sample of Ag and Zn nanoparticles is a gray powder of monocrystalline particles of irregular shape, the size of which varies from 160 to 350 nm. Particles of three sizes were most often found among Ag and Zn citrates, namely: 160 nm – 45 %, 210 nm – 35 %, 350 nm – 20 %. Studying the bactericidal properties of dispersed solutions of Ag and Zn citrates on microbial suspensions of test cultures of Escherichia coli (ser.O2), Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus epidermidis, we found that Ag citrate showed better bactericidal properties in relation to all experimental test cultures of Escherichia coli (ser.O2), Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus epidermidis, in contrast to the citrate solution Zn, which was only effective against Escherichia coli (ser.O2), and Staphylococcus epidermidis.

Early Postnatal Exposure to a Low Dose of Nanoparticulate Silver Induces Alterations in Glutamate Transporters in Brain of Immature Rats.

Due to strong antimicrobial properties, silver nanoparticles (AgNPs) are used in a wide range of medical and consumer products, including those dedicated for infants and children. While AgNPs are known to exert neurotoxic effects, current knowledge concerning their impact on the developing brain is scarce. During investigations of mechanisms of neurotoxicity in immature rats, we studied the influence of AgNPs on glutamate transporter systems which are involved in regulation of extracellular concentration of glutamate, an excitotoxic amino acid, and compared it with positive control—Ag citrate. We identified significant deposition of AgNPs in brain tissue of exposed rats over the post-exposure time. Ultrastructural alterations in endoplasmic reticulum (ER) and Golgi complexes were observed in neurons of AgNP-exposed rats, which are characteristics of ER stress. These changes presumably underlie substantial long-lasting downregulation of neuronal glutamate transporter EAAC1, which was noted in AgNP-exposed rats. Conversely, the expression of astroglial glutamate transporters GLT-1 and GLAST was not affected by exposure to AgNPs, but the activity of the transporters was diminished. These results indicate that even low doses of AgNPs administered during an early stage of life create a substantial risk for health of immature organisms. Hence, the safety of AgNP-containing products for infants and children should be carefully considered.

Experimental justification of the efficacy of Zn and Ag citrates in bird bacterioses

Experimental justification of the efficacy of Zn and Ag citrates in bird bacterioses

Capture and toxicity assessment of Ag citrate nanoparticles using jellyfish extract

In this study, Jellyfish extract at immunity reaction (JEI) captured Ag citrate nanoparticles (Ag citrate NPs) and reduce toxicity was investigated. JEI obtained from Aurelia aurita was used to assess the capture of Ag citrate NPs (10 mg/L, 2 mg/L) during 24 h, and the toxicity of JEI was assessed using a human cell line BEAS-2B. JEI was to reduce Ag citrate NPs in water by 34.55% (10 mg/L) after 1 h and by 40.62 ~ 41% (2 mg/L, 10 mg/L) after 24 h. When the BEAS-2B was exposed to 2 mg/L of Ag citrate NPs mixed with JEI showed increase 33.97% survival than 2 mg/L of Ag citrate NPs (0%). Furthermore, the apoptosis-related genes (p53, Bcl2, and Bax) showed no significant difference in expression upon exposure to JEI, compared to the control. JEI is to capture Ag citrate NPs and reduce its nano-toxicity. Therefore, such ability of JEI is likely to prove useful in the control of AgNPs flowing into the aquatic ecosystem.

Biosynthesised AgCl NPs using Bacillus sp. 1/11 and evaluation of their cytotoxic activity and antibacterial and antibiofilm effects on multi-drug resistant bacteria.

Silver nanoparticles (AgNPs) have attracted the attention of researchers due to their properties. Biological synthesis of AgNPs is eco-friendly and cost-effective preferred to physical and chemical methods, which utilize environmentally harmful agents and large amounts of energy. Microorganisms have been explored as potential biofactories to synthesize AgNPs. Bacterial NP synthesis is affected by Ag salt concentration, pH, temperature and bacterial species. In this study, Bacillus spp., isolated from soil, were screened for AgNP synthesis at pH 12 with 5 mM Ag nitrate (AgNO3) final concentration at room temperature. The isolate with fastest color change and the best ultraviolet-visible spectrum in width and height were chosen as premier one. AgNO3 and citrate salts were compared in terms of their influence on NP synthesis. Spherical Ag chloride (AgCl) NPs with a size range of 35-40 nm were synthesized in 1.5 mM Ag citrate solution. Fourier transform infrared analysis demonstrated that protein and carbohydrates were capping agents for NPs. In this study, antimicrobial and antitumor properties of the AgNP were investigated. The resulting AgCl NPs had bacteriostatic activity against four standard spp. And multi-drug resistant strain of Pseudomonas aeruginosa. These NPs are also cytotoxic to cancer cell lines MCF-7, U87MG and T293.

Enhancement of Singlet-Triplet Energy Transfer Between Dyes in a Polymer Film by Surface Plasmons of Gold Nanoparticles

The effect of the plasmon energy generated in Ag citrate hydrosol and ablated Au nanoparticles on the singlettriplet electron energy transfer between rhodamine 6G (R6G) and acriflavine (ACF) molecules incorporated into polyvinyl alcohol (PVA) films is studied. The increased efficiency of non-radiative energy transfer in the presence of Au nanoparticles and the increased lifetime of excited states of molecules are established.

Polymerization of benzylthiocyanate on silver nanoparticles and the formation of polymer coated nanoparticles

Polymerization of benzylthiocyanate on silver nanoparticles produces organic shell covered nanoparticles with controllable thickness in a one-pot process. Gram scale quantities of core–shell materials have been synthesized by this method. The methodology involves the addition of the precursor into Ag–citrate solution and the shell nucleates over a period of three weeks with complete precipitation of the core–shell material which can be dispersed subsequently in organic solvents. The material has been characterized using transmission electron microscopy, X-ray diffraction, FT-IR, laser desorption mass spectrometry, thermogravimetry, surface enhanced resonance Raman spectroscopy (SERRS) and Raman imaging. A typical composite material consists of a silver core of 40 nm diameter coated with a polymeric shell of 8 nm thickness. The polymer exhibits characteristic features in mass spectrometry and vibrational spectroscopy. The core–shell structure of nanoparticles is imaged for the first time using the Raman intensity of the shell. Proton assisted polymerization of benzylthiocyanate occurs on the silver surface, leading to a linear chain which subsequently deposits on the nanoparticle surface resulting in the core–shell structure.

The influence of noble-metal-containing cathodes on the electrochemical performance of anode-supported SOFCs

In order to enhance the catalytic activity of the cathode for oxygen reduction and thus to increase the electrochemical performance of planar anode-supported solid oxide fuel cells, Pd, Ag, or Pt was added to the cathode. Four routes were used to add these noble metals: infiltration of the cathode with a Pd solution, deposition of Pt on the electrolyte surface, mixing of La0.65Sr0.30MnO3 (LSM) and YSZ cathode powders with different metal precursors (Pt and Pd black, Pd on activated carbon, Ag powder, Ag2O, Ag acetate, Ag citrate, Ag2CO3, colloidal Ag, AgNO3), and synthesis of LSM powder with the addition of AgNO3. Between 750 and 900 °C no electrocatalytic effect occurred with respect to the presence of Pt, either added by deposition on the electrolyte or by mixing with cathode powders. Infiltration of the cathode with a Pd solution or mixing with Pd black did not result in a positive effect either. A catalytic effect was only found with Pd on activated carbon and in particular at lower temperatures. Cells prepared with Ag powder and Ag2O showed an improved electrochemical performance compared to Ag-free cells sintered at the same temperature (920 °C). However, in comparison to Ag-free cells sintered at the standard temperature (1100 °C) lower current densities were measured. This can be explained by a weak contact between electrolyte and cathode functional layer and an insufficiently sintered cathode. A detrimental effect was observed regarding the addition of the other Ag precursors. Thermal decomposition of these precursors resulted in the formation of large pores in the cathode.