scholarly journals Silver nanoparticles embedded in polystyrene-polyvinyl pyrrolidone nanocomposites using γ-ray irradiation: Physico-chemical properties

2017 ◽  
Vol 7 ◽  
pp. 1319-1328 ◽  
Author(s):  
Islam Ali ◽  
Mahmoud R. Akl ◽  
Gamal A. Meligi ◽  
Tawfik A. Saleh
Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1883
Author(s):  
Martin Pisárčik ◽  
Miloš Lukáč ◽  
Josef Jampílek ◽  
František Bilka ◽  
Andrea Bilková ◽  
...  

Phosphorus-containing heterocyclic cationic surfactants alkyldimethylphenylphospholium bromides with the alkyl chain length 14 to 18 carbon atoms were used for the stabilization of silver nanodispersions. Zeta potential of silver nanodispersions ranges from +35 to +70 mV, which indicates the formation of stable silver nanoparticles (AgNPs). Long-chain heptadecyl and octadecyl homologs of the surfactants series provided the most intensive stabilizing effect to AgNPs, resulting in high positive zeta potential values and smaller diameter of AgNPs in the range 50–60 nm. A comparison with non-heterocyclic alkyltrimethylphosphonium surfactants of the same alkyl chain length showed better stability and more positive zeta potential values for silver nanodispersions stabilized with heterocyclic phospholium surfactants. Investigations of biological activity of phospholium-capped AgNPs are represented by the studies of antimicrobial activity and cytotoxicity. While cytotoxicity results revealed an increased level of HepG2 cell growth inhibition as compared with the cytotoxicity level of silver-free surfactant solutions, no enhanced antimicrobial action of phospholium-capped AgNPs against microbial pathogens was observed. The comparison of cytotoxicity of AgNPs stabilized with various non-heterocyclic ammonium and phosphonium surfactants shows that AgNPs capped with heterocyclic alkyldimethylphenylphospholium and non-heterocyclic triphenyl-substituted phosphonium surfactants have the highest cytotoxicity among silver nanodispersions stabilized by the series of ammonium and phosphonium surfactants.


2018 ◽  
Vol 7 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Sarah Ghanbari ◽  
Hamideh Vaghari ◽  
Zahra Sayyar ◽  
Mohammad Adibpour ◽  
Hoda Jafarizadeh-Malmiri

Abstract Silver nanoparticles (AgNPs) were synthesized using Aspergillus fumigatus (A. fumigatus) mycelia extract via the hydrothermal method. The main reducing and stabilizing groups and components of A. fumigatus extract, such as amine, hydroxyl, amid, protein, enzymes, and cell saccharide compounds, were identified by Fourier transform infrared (FT-IR). Central composition design was used to plan the experiments, and response surface methodology was applied to evaluate of the effects of independent variables, including the amount of the prepared extract (5–7 ml) and heating time (10–20 min) at 121°C and 1.5 bar), on the particle size of the synthesized AgNPs, as manifested in broad emission peak (λmax). More stable and spherical monodispersed AgNPs, with mean particle size, polydispersity index (PDI) value, and maximum ζ potential value of 23 nm, 0.270, and +35.3 mV, respectively, were obtained at the optimal synthesis conditions using 7 ml of A. fumigatus extract and heating time of 20 min. The synthesized AgNPs indicated high antibacterial activity against both Gram-positive and Gram-negative bacteria.


2020 ◽  
Vol 32 (6) ◽  
pp. 1335-1342
Author(s):  
Kh. E. Yunusov ◽  
A.A. Sarymsakov ◽  
S.V. Mullajonova ◽  
F.M. Turakulov ◽  
S. Sh. Rashidova

Stable silver nanoparticles in solutions of sodium-carboxymethylcellulose (Na-CMC) were synthesized and their structure and physico-chemical properties were evaluated. The form and sizes of silver nanoparticles formed in solutions of CMC and cotton fabrics were studied using UV-VIS spectroscopy, atomic force microscopy and transmission electron microscopy methods. It was found that silver nitrate concentration increase in sodium carboxymethylcellulose solutions, as well as photoirradiation of the hydrogel lead to the changes of the silver nanoparticles size and shape. Investigations have also shown that spherical silver nanoparticles with sizes of 5-35 nm and content of 0.0086 mass% in cotton fabrics possess high bactericidal activity. Stabilization of silver nanoparticles has preserved bactericidal and bacteriostatic activities during the washing of cotton fabrics and textiles on their base.


Author(s):  
Hashem Yaghoubi ◽  
Amin Izadpanah ◽  
Shahla Nedaei ◽  
Hossein Akbari ◽  
Elmira Mikaeili Agah ◽  
...  

Background: The use of nanoparticles has markedly increased in biomedical sciences. The silver nanoparticles (AgNPs) have been investigated for their applicability to deliver chemotherapeutic agents in cancer treatment. However, the existing chemical and physical methods of synthesizing AgNPs are considered inefficient and expensive, and are fraught with toxicity. Objective: Natural products have emerged as viable candidates for nanoparticle production, including the use of Terfezia boudieri (T. boudieri), a member of the edible truffle family. Accordingly, our goal was to synthesize AgNPs using the aqueous extract of T. boudieri (green synthesized AgNPs). Since certain infectious agents are linked to cancer, we further investigated their potential as anti-cancer and antibacterial agents. Methods: The physico-chemical properties of green synthesized AgNPs were analyzed by UV-Vis, FT-IR, XRD, SEM and TEM. In addition, their potential to inhibit cancer cell (MCF-7 and AGS) proliferation as well as the growth of infectious bacteria were investigated. Synthesis of AgNPs was confirmed by the presence of an absorption peak at 450nm by spectroscopy. Results: The size of nanoparticles ranged between 20-30nm and exerted significant cytotoxicity and bactericidal effects in a concentration and time dependent manner compared to T. boudieri extract alone. Interestingly, synthesis of smaller AgNPs correlated with longer synthesis time and enhanced cytotoxic and bactericidal properties. Conclusion: This study shows that synthesis of smaller AgNPs correlated with longer synthesis time and enhanced cytotoxic and anti-bacterial effects.


NanoNEXT ◽  
2021 ◽  
pp. 16-25
Author(s):  
Henry L. Barnabas ◽  
Ngoshe A.M ◽  
Joshua A Gidigbi

Nanoparticles are known to be of wide applications in various fields of human endeavours. Many methods of syntheses such as physical, chemical are harmful to the environment, thus, this study utilised green production of nanoparticles via waste product such as Citrulus vulgaris seed. Oil was extracted using soxhlet extractor from the prepared Citrulus vulgaris seed. Physico-chemical properties such as percentage yield, acid value, peroxide value were carried out on the Citrulus vulgaris seed oil. Citrulus vulgaris was further processed to form lecithin. The lecithin extracted was characterized for colour, Peroxide Value, Acetone Insoluble (AI), Acid Value, solubility in water and organic solvents. The result of the physico-chemical parameters was in conformity with the standard and various literatures. Therefore, lecithin is processed into dispersed aqueous silver nanoparticles by the addition of silver nitrate. The chemical reaction was monitored progressively using visual assessment, UV-visible and FTIR Spectroscopy. The size and surface of the dispersed silver nanoparticles produced was analysed using Atomic Force Microscopy. Therefore, a dispersed aqueous silver nanoparticle was produced from lecithin made from Citrulus vulgaris seed oil.


2021 ◽  
Vol 18 ◽  
Author(s):  
Sonia Parashar ◽  
Manish Kumar Sharma ◽  
Chanchal Garg ◽  
Munish Garg

: Unprincipled use of antibiotics has led to the antimicrobial resistance (AMR) against mostly available compounds and now become a major cause of concern for the scientific community. However, in the past decade, green synthesized silver nanoparticles (AgNPs) have received greater attention for the development of newer therapies as antimicrobials by virtue of their unique physico-chemical properties. Unlike traditional antibiotics, AgNPs exert their action by acting on multiple mechanisms which make them potential candidates against AMR. Green synthesis of AgNPs using various medicinal plants has demonstrated broader spectrum of action against several microbes in a number of attempts. The present paper provides an insight into the scientific studies that have elucidated the positive role of plant extracts/phytochemicals during green synthesis of AgNPs and their future perspectives. The studies conducted so far seem promising still, a few factors like, the precise mechanism of action of AgNPs, their synergistic interaction with biomolecules, and industrial scalability need to be explored further till effective drug development using green synthesized AgNPs in healthcare systems against AMR is established.


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