Preparation Of Nanosilver Research Articles

Preparation of nano-silver containing black phosphorus based on quaternized chitosan hydrogel and evaluating its effect on skin wound healing

Hydrogels with favorable biocompatibility and antibacterial properties are essential in postoperative wound hemorrhage care, facilitating rapid wound healing. The present investigation employed electrostatic adsorption of black phosphorus nanosheets (BPNPs) and nano‑silver (AgNPs) to cross-link the protonated amino group NH3+ of quaternized chitosan (QCS) with the hydroxyl group of hyaluronic acid (HA). The electrostatic interaction between the two groups resulted in the formation of a three-dimensional gel network structure. Additionally, the hydrogel containing AgNPs deposited onto BPNPs was assessed for its antibacterial properties and effects on wound healing. Hydrogel demonstrated an outstanding drug-loading capacity and could be employed for wound closure. AgNPs loaded on the BPNPs released silver ions and exhibited potent antibacterial properties when exposed to 808 nm near-infrared (NIR) radiation. The ability of the hydrogel to promote wound healing in an acute wound model was further evaluated. The BPNPs were combined with HA and QCS in the aforementioned hydrogel system to improve adhesion, combine the photothermal and antibacterial properties of the BPNPs, and promote wound healing. Therefore, the reported hydrogels displayed excellent biocompatibility and hold significant potential for application in the field of tissue engineering for skin wound treatment.

Experimental study on the preparation of monodisperse nano-silver by hydrothermal synthesis

As a new material with wide application prospect, nano-silver is getting high attention. Hydrothermal synthesis has the advantages of green, easy operation and low cost, and is a promising technology for the preparation of nano-silver. In this paper, the effects of reaction time, reaction temperature, precursor concentration, PVP concentration and modifier addition on the particle size distribution and surface morphology of nano-silver during the subcritical hydrothermal reaction were optimized by comparing the supercritical and subcritical hydrothermal methods. Then, the important role and reaction mechanism of PVP as a modifier and the formation mechanism of spherical nano-silver particles were analyzed. The experimental results showed that the average particle size of 23.68 nm can be obtained by using NaHCO3 and PVP as reducing and dispersing agents, the reaction time is 5 h, the reaction temperature is 180 °C, and the concentrations of AgNO3 and PVP are 0.1 M and 0.3 M, respectively, to obtain the more uniformly dispersed silver nanoparticles. The results provide an important reference for future research on the preparation of conductive pastes.

The Preparation of Nano Silver by Chemical Reduction Method

A silver nanostructures prepared by using chemical reduction method. The silver nanoparticles were prepared with diameters of about (20 nm). Numerous techniques had been used to study the optical, structural like the UV-Vis absorption spectrometer, Ttransmission Electron Microscopy (TEM), Field-Emission Scanning Electron microscope (FESEM), and X-ray diffraction (XRD). The practical results exhibited the absorption spectrum of the prepared nanoparticles at (357 nm), it was found that there is a relationship between the positions of the optical absorption peak and the size of the silver nanoparticles. The analysis of TEM results showed the presence of nanoparticles in the range (20 nm). The analyzing of XRD results explained the crystal structure for silver nanoparticles. It is found a cubic unit cell have a lattice constants (a = 4.0855 Å), with the Miller indices were (111), (002), (002), and (113).

Preparation of Nano-Silver Dressing for Application on Postoperative Rehabilitation Nursing of Patients with Gastrointestinal Surgery

This study was to explore the effect of nursing and repairing methods of nano-silver dressing (NSD) on the postoperative rehabilitation of gastrointestinal surgery (GIS) patients. For preparation of the nano-silver dressing, ammonia water was added to the solution containing silver particles to generate ammonium nitrate, and the coating solution was then uniformly coated on the surface of the substrate layer, and pre-baked at 100–180 °C to finally obtain a medical dressing. 80 GIS patients admitted to the hospital were selected and randomly divided into the control group treated with ordinary dressing (40 cases, group OD) and the observation group treated with NSD (40 cases, group NSD). The treatment effect and postoperative recovery results of the two groups of patients were compared, and the performance of the NSD was tested. The results showed that it was found that the recovery status of patients in group NSD was better (P < 0.05), and the NSD had good bacteria killing effect and microbial barrier effect. In conclusion, NSD could continue to act on the wound surface, improve the body’s immunity, and promote the rapid recovery of postoperative incisions, with obvious clinical effect.

Influence of preparation of silver nanoparticles in carriers based on polymer/inorganic hybrids on the mineral composition of chicken eggs

The solution to the problem of reducing the use of antibiotics in the production of edible eggs is possible through the development and use of alternative bactericidal preparations, including those based on nanosilver. Obtaining biocompatible and biodegradable polymer/inorganic carriers of nanosilver provides for the study of its cumulative qualities which determine the safety of edible chicken eggs. The study investigated the mineral composition of edible eggs when feeding Hy-Line W36 laying hens solutions of the nanosilver preparation in carriers based on polymer/inorganic hybrids (AgNPs/SPH) given in the concentrations of 0, 1.0, and 2.0 mg/L of water (0, 0.2 and 0.4 mg/hen per day) three times at 10 day intervals. Oral administration to laying hens of an aqueous solution of silver nanoparticles in carriers based on polymer/inorganic hybrids at doses of 0.2 and 0.4 mg per hen per day in a dose-dependent manner increased the silver content and did not significantly affect the content of copper, zinc, iron, and lead in the eggshell. The preparation of silver nanoparticles did not affect the content of silver, copper, zinc, iron and lead in the albumen and yolk of chicken eggs after the first and second application, and after the third treatment of laying hens contributed to an increase in the silver content in the egg albumen and yolk but did not affect the content in them of copper, zinc, iron and lead. A single feeding of a solution of a preparation of nanosilver in carriers based on polymer/inorganic hybrids to hens at doses of 0.2 and 0.4 mg per hen per day after 10 days, contributed to a significant increase in the yolks of chicken eggs due to a decrease in the albumen and eggshell. The second and third application of nanosilver to poultry in the indicated doses contributed to a decrease in its proportion in the albumen and in the yolk due to a significant increase in its proportion in the shell. Selective accumulation of in-shell silver can be a promising means of improving the safety and security of chicken eggs when they are microbially contaminated. The results of using nanosilver based on polymer/inorganic hybrids in laying hens can be the basis for the development of methods for increasing the bactericidal properties of the shell and the safety of edible eggs.

Вплив препарату наносрібла в носіях на основі полімер/неорганічних гібридів на мінеральний склад курячого посліду

Nanosilver preparation is synthesized in the carriers based on polymer/inorganic hybrids in aqueous dispersion form by in situ synthesis of silver nanoparticles in biocompatible and biodegradable polymer/inorganic hybrid based on silica sol and polyacrylamide. Hydrophilic polymer/inorganic hybrid used as a carrier for silver nanoparticles was synthesized by the developed method of directly grafting polyacrylamide "from" the unmodified surface of silica sol. The size of silver particles in the preparation was <10 nm. Studies have found that single, double and three-fold sprinkling of laying hens of nanosilver in polymer/inorganic hybrid carriers at concentrations of 1.0 and 2.0 mg/l (at doses of 0.2 and 0.4 mg per hen per day) did not affect the consumption of feed, water and egg productivity of poultry. The obtained nanosilver preparation is safe for laying hens and it does not cause disorders of clinical condition, diseases and poultry death during three-fold drinking with 10 days interval. After drinking the preparation of nanosilver to the laying hens at doses of 0.2 and 0.4 mg per head per day with an interval of 10 days, the dose-dependent amount of silver in the manure was increased only after a single drinking and after double and triple drinking, it did not affect the content of silver, copper, zinc, iron and lead. Single drinking of laying hens with a solution of silver nanoparticles in carriers based on polymer/hybrids at a concentration of 1.0 mg/l (0.2 mg per hen per day) increased the silver content in hen manure by 20% compared to the control group, and it did not affect the content of copper, zinc, iron and lead in manure. Nanosilver preparation at a concentration of 2.0 mg/l (0.4 mg per hen per day) increased the silver content by 44% in hen manure on the 10th day only after the first drinking of the preparation and it did not affect the content of copper, zinc, iron and lead compared to the control and with similar data of hens to which the same preparation was given at a concentration of 1.0 mg/l.

Structural characterization and biological activities of a novel polysaccharide from Glehnia littoralis and its application in preparation of nano-silver

A novel polysaccharide (GLP) with a molecular weight of 1.37 × 105 Da was purified from the roots of G. littoralis. Using monosaccharide composition, methylation analysis, GC–MS, 1D and 2D NMR, the structure of GLP was determined to be a 1 → 4)-α-D-Glcp glycoside linkage, while the terminal group of 1→)-α-D-Glcp was bonded to the main chain via O-6. Then, GLP-NPs were prepared by nano-precipitation method, the particle size of GLP-NPs was 288.4 nm and PDI was 0.340. GLP-NPs-AgNPs were prepared using GLP-NPs as reducing agent. GLP-NPs-AgNPs were characterized by ultraviolet-visible spectrophotometer (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM) and X-ray diffraction (XRD). The yield of GLP-NPs-AgNPs was 38.77%, the particle size was 12.5 nm and the chelation rate of silver nanoparticles with polysaccharides was 67.5%. GLP-NPs-AgNPs had better antioxidant and antibacterial activities than GLP and GLP-NPs. In the present work, a simple and eco-friendly approach for the synthesis of silver nanoparticles (AgNPs) using G. littoralis polysaccharides nanoparticles (GLP-NPs) as reducing agent.

<i>Nicotiana tabacum</i> Mediated Green Synthesis of Silver Nanoparticles and Ag-Ni Nanohybrid: Optical and Antimicrobial Efficiency

A sustainable method was considered for the preparation of nanosilver and its allied nanoparticles. Nicotiana tabacum, an abused plant, has found an application as a bio-chemical instead of lethal chemical in the synthesis of nanoparticles. As part of green chemistry implementation, double distilled water was the solvent used for extraction. The phytochemicals present were analyzed using standard procedures. Nanoparticle synthesis was carried out at varying precursor concentrations, and the reaction was monitored with a UV-visible spectrophotometer. Another optical characterization was also achieved with photoluminescence. Other characterization involved: X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDS), and Fourier transform infrared spectroscopy techniques (FTIR). A matched phase identification of nanosilver resembled a face-centered cubic of Ag with a mean size of 11.68 nm, and a lattice constant of 4.0862 Å. The Ag NPs displayed activity against clinical isolates of fungi, Gram-positive, and Gram-negative bacteria as the growth inhibition was significant at P < 0.05. Ag NPs obtained from the Nicotiana tabacum proved to be an antibacterial and antifungal candidate, unlike the Ag NPs derived using chemical and physical methods, which were harmful for this purpose. Both the Ag NPs and Ag-Ni NPs displayed optical activity, which qualifies them for application in visual materials.

Prospects for the use of silver nanoparticles for the creation of composite dental materials with antimicrobial properties

Annotation. Due to the uncontrolled use of antibiotics, the issue of antibiotic resistance has become vitally important. Search the alternative antimicrobials preparation is urgent question. Despite significant achievements in dentistry, the quality of root canals endodontic treatment remains relevant issue. Enterococcus faecalis is one of the ESKAPE group pathogen as well as one of the most common causative agents of intracanal caries. Ag nanoparticles (AgNPs) have shown high efficacy against several polyresistant strains. Therefore, the purpose of our study was to evaluate the possibility of AgNPs using to create composite dental materials with antimicrobial activity. Statistical processing of the obtained results was performed using the software package for statistical data processing Graph Pud Prism 8 with the definition of the Student's criterion. The antibacterial effect of Ag NPs was evaluated against the clinical strain of E. faecalis by determining the minimum inhibitory concentration (serial dilution method) and the minimum bactericidal concentration (direct inoculation of the microorganism from liquid onto solid media). The influence of AgNPs on the multiplication of the bacterial population and on the processes of biofilm formation were investigated. The MIC and MBC were 2.5 µg / ml. Time-kill curve of E. faecalis strain indicates the need for prolonged contact of microorganisms with the nanosilver preparation and reflect a gradual decrease in the number of bacteria in the sample. AgNPs inhibit the formation of biofilms in the early stages and effectively affect 3-days biofilms. The action of the silver nanoparticles at the initiation stage reduced the total volume of the unformed biofilm by 2 times at concentrations of 10 and 20 MICs. The inhibitory effect of silver on the formed 3-day biofilm was dose-dependent and increased with increasing concentration. The obtained results show AgNPs inhibit the growth and reproduction of planktonic and film forms of E. faecalis and can be used to create dental composite with antimicrobial activity.

Tetrabutylphosphonium-salicyl-imine-chitosan metallo-Schiff bases:Supramolecular architectures as multifunctional pharmacological materials.

The current work provides a simple synthetic route for the preparation of poly-(phosphonium-salicyl)-grafted chitosan Schiff bases (PPCSB), its M(II) complexes (M = Cu or Pd) and silver nanobiocomposites (NBCs). The ex-situ protocol was used for preparation of nanosilver (AgNPs) using NaBH4 as a reducing agent then capped either by PPCSB or Pd(II)PPCSB to fabricate NBCs {AgNPs@PPCSB, AgNPs@Pd(II)PPCSB}. Structural, morphological and physicochemical characterizations of the new architectures were examined based upon diverse spectral and microscopic techniques. The antibacterial properties of new compoundswas investigated against gram positive (S. aureus, B.subtilis) and gram negative (E. coli, P. aeruginosa) bacterial strains. Unexpectedly, the M(II)PPCSB complexes were found to be more active against all tested bacterial strains than NBCs (AgNPs@PPCSB, AgNPs@Pd(II)PPCSB). Meanwhile, as revealed from ZOI values, the Cu(II)PPCSB is the most potent bactericidal agent against all tested bacterial strains except E. coli species which is more affected by Pd(II)PPCSB

Green synthesis of nano-silver particles using plant active substance from lemongrass extract

Biosynthesis of nanoparticles by plant extracts is currently under exploitation. Plant extracts are very cost effective and eco-friendly and thus can be an economic and efficient alternative. This study investigates the mechanism of preparation of nano-silver using a plant active substance from lemongrass extract. The lemongrass ethanol extract was prepared using an ultrasonic cell crusher. Spherical silver nanoparticles were prepared with lemongrass extract and silver nitrate. The reaction mechanism of the preparation of nano-silver by plant extracts was analyzed by infrared and X-ray photoelectron spectrometer (XPS) measurements. The uniform and stable spherical silver nanoparticles with an average particle size of 22.99 nm were synthesized. Amide compounds in plant extracts may act as reductants and protective agents. The biomass of plants produces their nanomaterials through a process called biomineralisation. Thus, plant active substances can be used widely, and biological methods are completely feasible and worth studying for the chemical procedures, which are environmentally friendly and convenient.

Nanosilver Biocidal Properties and Their Application in Disinfection of Hatchers in Poultry Processing Plants.

The aim of this study was to use aqueous suspensions of silver nanoparticles with a wide spectrum of particle sizes, variable morphology, high stability, and appropriate physicochemical properties to examine their bactericidal and fungicidal properties against microorganisms present in poultry processing plants. At the same time, the particles were tested for preventing the production of odorogenous pollutants during incubation and thereby reducing the emission of harmful gases from such types of facilities. The results show that the use of nanosilver preparations in order to disinfect eggs and hatchers reduced microbiological contamination. The bactericidal and fungicidal efficacy of the applied preparation was comparable to UV radiation and its effectiveness increasing during the incubation. Good results were achieved in terms of the level of organic gaseous contaminants, which decreased by 86% after the application of the nanosilver preparation.

Silver (Ag) in tissues and eggshells, biochemical parameters and oxidative stress in chickens

Abstract This study aimed to assess levels of silver nanoparticle residues in eggshells and tissues as well as the levels of selected biochemical parameters and oxidative stress indices in chickens hatched from nanosilver disinfected eggs. The samples included 40 Greenleg Partridge chicks allocated into two groups. The experimental group (group D) consisted of chickens hatched from eggs disinfected with a nanosilver preparation prior to incubation, while the control group (group C) included chickens whose eggs were exposed to UV radiation for disinfection. The eggshells and kidney sections obtained from group D chickens showed a significantly higher silver level compared to group C. For the biochemical parameters, only the uric acid content was higher in group D compared to group C. Analysis of the antioxidative stress biomarkers (superoxide dismutase and catalase), showed a significant increase in group D in relation to group C.

Preparation of Nanosilver and Nanogold Based on Dog Rose Aqueous Extract

This paper describes a process of obtaining nanosilver and nanogold based on chemical reduction using substances contained in the aqueous extract of dog rose (Rosa canina). The resulting products were subjected to spectrophotometric analysis (UV-Vis), and testing of the nanoparticles' size and suspension stability was carried out by measuring the electrokinetic potential, ζ, via dynamic light scattering (DLS). Solid samples were imaged by scanning electron microscopy (SEM). The obtained data were given to statistical analysis in order to illustrate the properties of the suspension depending on the values of the input parameters: metal salts concentration, pH of the reaction mixture, and process temperature. In the course of the work, samples of nanosilver and nanogold were obtained, which were stable for over two months and which had a monomodal particle size distribution.

Characteristics and electrochemical mechanisms of a nanosilver solution formed by anodic dissolution with high DC voltage

Nanosilver solution, prepared by anodic dissolution with high DC voltage in doubly distilled water, is free of undesirable chemicals and forms a highly pure product which is suitable for different applications, especially in the medical and pharmaceutical fields. In this study high DC voltage electrolysis was implemented to form nanosilver solutions with varying electrode diameters, anode-cathode distances, and electrolysis duration. The process was monitored while the cell was in operation, and the characteristics of the resulting solution were analysed afterwards. Cell reactions included: colour changes in the solution bulk due to the reduction of silver ions forming nanoparticles, anodic dissolution of silver, intense gas evolution at both electrodes, and chemical reactions in the solution causing nanosilver formation. UV-Vis characteristics, particle size distribution, transmission electron microscopy (TEM) images, solution concentrations, conductivities, and ζ-potentials were all found to depend on the electrode’s distances, temperature, electrolysis duration, and current density. Nanosilver preparation can thus be considered a combination of electrochemical reactions (such as silver dissolution at anode and water decomposition to generate hydrogen and oxygen), and chemical reactions between the electrolytic products from the solution bulk.

UV-curable nano-silver containing polyurethane based organic–inorganic hybrid coatings

The preparation of nano-silver containing polyurethane based UV-curable organic–inorganic hybrid coatings that have antibacterial activity is presented in this paper. Trimethoxysilane end-capped bis[(4-β-hydroxyethoxy)phenyl] methyl phosphine oxide urethane was synthesized as a coupling agent and used to improve the compatibility between the organic and inorganic phases of the hybrid coating. Due to its strong antibacterial activity, silver nanoparticles were prepared and added to the nanocomposite formulations. The relationships between the amount of coupling agent and the final coating properties were investigated. The hybrid coatings presented good thermal stability. Tests for abrasion, hardness, gloss, and adhesion of the coatings were also performed. The morphological investigation was performed by SEM to determine the size of the silver nanoparticles. The nano-silver containing coatings exhibited good antibacterial activity against E. coli and S. aureus.

Effects of the Ratio of Surface Protective Agent on the Preparation of Nano-Silver

It has many advantages with liquid phase reduction method to prepare the nano-silver, such as experimental conditions are simple, low cost, energy-saving, etc.. At the same time, the nano silver powder prepared by this method has high surface activity, catalytic property and wide usage. In this paper, nano-silver powder was prepared by changing the amount of protective agents with chemical liquid phase reduction method. This paper focuses on the impact of the amount of protective agent on the nano-silver. In addition, we also analyzed the reaction temperature, PH value of solution, viscosity and electrical conductivity on the preparation of nano-silver. Finally, test results from the TEM shows that the nano-silver was prepared with smaller size, uniform size and good dispersion.

Preparation of nanosilver by using water-insoluble reducing agent o -phenylenediamine

Spherical and dendritic nanometre silver is prepared by using the water-insoluble reducing agent o-phenylenediamine (OPD) in rapid-mixing and interface methods, respectively. Particle size and morphology of nanosilver are analysed using the scanning electron microscope and UV–visible spectrophotometer, whereas crystal structure characterisations are performed by X-ray. The effects of reactant ratio and concentration are investigated. The results show that optimal AgNO3 concentration range for growth of spherical nanometre silver is 0.6 mol/l and the optimal ratio of AgNO3 and OPD is 1:1 in the protection of polyvinylpyrrolidone. The mechanism of OPD reduction method would be reached and the reaction equation could be speculated by inductively coupled plasma and infrared spectrometry.

Single step preparation of nanosilver loaded calcium phosphate by low temperature co-conversion process

The preparation and characterization of nanosilver loaded calcium phosphate aiming to enhance the bactericidal performance by a single step co-conversion technique using low temperature ion exchange phosphorization in combination with Tollen's reaction were performed. Silver nitrate was used as a silver ion supply source (0.001-0.1 M) and glucose was employed as a reducing agent. After conversion, surface and shell zones of all samples comprised hydroxyapatite and metallic silver as the main phases regardless of silver nitrate concentration. However, hydroxyapatite, residual calcium sulfate and monetite were found in the core zone when using silver nitrate concentration lower than 0.1 M. The microstructure of all samples comprised the distribution of spherical-shaped silver nanoparticles within the cluster of calcium phosphate nanocrystals. Total silver content (range, 0.09-6.5 %) in the converted samples was found to linearly increase with increasing silver nitrate content. Flexural modulus and strength of converted samples generally decreased with increasing silver content. Effective antibacterial activity of two selected samples (0.001 and 0.005 M AgNO(3)) against two bacterial strains (Pseudomonas aeruginosa and Staphylococcus aureus) was observed. Cytotoxic potentials by MTT assay of both samples were observed at 24 and 48 h extraction respectively.

Effects of Different Reducing Agents and Protective Agents on the Preparation of Nano-Silver Powder

Solution chemical reduction method is a means which used reducing agent in aqueous or organic systems to deoxidize silver ions. Its essence is an integrated process of the electrochemistry, thermodynamics, kinetics and fluid dynamics and so on. The process determines the physical and chemical properties such as the size distribution of powder, purity and reunion situations, etc. Nano-silver powder has high surface activity and catalytic properties, and is widely used to a lot of fields. So it has very important realistic significance to study the preparation method. In this paper, nano-silver powder was prepared with industrial AgNO3 as raw materials, sodium borohydride or hydrazine hydrate as reducing agent, polyvinyl alcohol, SDBS or polyvinylpyrrolidone(PVP) as the surface protective agent by solution chemical reduction method. The influences of different reducing agents and protective agents on the preparation of nano-silver were analyzed. The results from the XRD diffraction analysis and TEM show that it can be obtained high purity flake nano-silver in the reaction temperature range of 50-60°C.