scholarly journals Synergistic Antifungal Activity of Green Synthesized Silver Nanoparticles and Epoxiconazole against Setosphaeria turcica

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Weidong Huang ◽  
Minhui Yan ◽  
Haiming Duan ◽  
Yaling Bi ◽  
Xinxin Cheng ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Integrated Control ◽  
Antimicrobial Effect ◽  
Colony Growth ◽  
Setosphaeria Turcica ◽  
Ligustrum Lucidum ◽  
In Vitro Inoculation ◽  
Average Size

It is urgent to develop highly efficient and eco-friendly antimicrobial agents for integrated control of phytopathogens. Silver nanoparticles (AgNPs) were synthesized by Ligustrum lucidum leaf extract. UV-vis spectrum showed that there was a strong absorbance at 438 nm. Transmission electron microscopy (TEM) images displayed that synthesized nanoparticles were near spherical with an average size of 13 nm. The antimicrobial effect of AgNPs was evaluated through methods of paper disk diffusion, colony growth, conidia germination, and in vitro inoculation. The 50% inhibition concentration (IC50) of AgNPs against Setosphaeria turcica was 170.20 μg/mL calculated by SPSS 13.0. In addition, it displayed a significant synergistic antifungal effect when AgNPs were combined with epoxiconazole at the ratios of 8 : 2 and 9 : 1. The results of this study provide a novel fungistat not only for comprehensive control of plant fungi but also for reducing chemical pesticides use and avoiding drug-resistant phytopathogen generation.

scholarly journals Biosynthesis of Silver Nanoparticles Mediated by Entomopathogenic Fungi: Antimicrobial Resistance, Nanopesticides, and Toxicity

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 852
Author(s):  
Tárcio S. Santos ◽  
Tarcisio M. Silva ◽  
Juliana C. Cardoso ◽  
Ricardo L. C. de Albuquerque-Júnior ◽  
Aleksandra Zielinska ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Filamentous Fungi ◽  
Entomopathogenic Fungi ◽  
Antimicrobial Agents ◽  
Insect Pests ◽  
Insect Control ◽  
Biological Synthesis ◽  
Biological Methods ◽  
Potential Use

Silver nanoparticles are widely used in the biomedical and agri-food fields due to their versatility. The use of biological methods for the synthesis of silver nanoparticles has increased considerably due to their feasibility and high biocompatibility. In general, microorganisms have been widely explored for the production of silver nanoparticles for several applications. The objective of this work was to evaluate the use of entomopathogenic fungi for the biological synthesis of silver nanoparticles, in comparison to the use of other filamentous fungi, and the possibility of using these nanoparticles as antimicrobial agents and for the control of insect pests. In addition, the in vitro methods commonly used to assess the toxicity of these materials are discussed. Several species of filamentous fungi are known to have the ability to form silver nanoparticles, but few studies have been conducted on the potential of entomopathogenic fungi to produce these materials. The investigation of the toxicity of silver nanoparticles is usually carried out in vitro through cytotoxicity/genotoxicity analyses, using well-established methodologies, such as MTT and comet assays, respectively. The use of silver nanoparticles obtained through entomopathogenic fungi against insects is mainly focused on mosquitoes that transmit diseases to humans, with satisfactory results regarding mortality estimates. Entomopathogenic fungi can be employed in the synthesis of silver nanoparticles for potential use in insect control, but there is a need to expand studies on toxicity so to enable their use also in insect control in agriculture.

scholarly journals Bio-Inspired Fabrication of Silver Nanoparticles Using High Altitude Squamulose Lichen Extract and Evaluation of its Antioxidant, Anticandida and Cytotoxic properties

2021 ◽  
Author(s):  
S Shanthi ◽  
V. Uma Maheshwari Nallal ◽  
Krishnan Anand ◽  
Balasubramani Ravindran ◽  
Soon Woong Chang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Silver Nanoparticles ◽  
High Altitude ◽  
Usnic Acid ◽  
Nanoparticle Synthesis ◽  
Spectroscopic Studies ◽  
Binding Energies ◽  
Average Size ◽  
Nano Medicine

Abstract Bio-inspired nanoparticle synthesis has attracted substantial interest among the scientific society owing to its eco-friendly and non-toxic nature. In the present study, Silver nanoparticles (AgNPs) were synthesized using high altitude squamulose lichen – Cladonia subradiata and characterized using different techniques. The antioxidant and anticandida activity of AgNPs were evaluated using multiple in-vitro assays. In-silico molecular docking analysis and in-vitro cytotoxic assay was performed to determine the anti-cancer potential of synthesized AgNPs. The results of the spectroscopic studies revealed the successful synthesis of AgNPs and the presence of different functional groups suggesting the involvement of phytocompounds in the reduction and capping of AgNPs. The average size of the AgNPs was 20 nm and predominantly spherical in shape. AgNPs demonstrated excellent DPPH free radicals scavenging activity with an IC50 value of 7.51 ± 0.4 µg/mL. C.albicans was identified as the most susceptible strain from the anticandida studies. Usnic acid and Pulvinic acid exhibited low binding energies and showed excellent inhibition interaction with EGFR lung cancer protein. The in-vitro cytotoxic results were impressive with an IC50 value of 28.75 µg/mL for A549 lung cancer cells treated with AgNPs. Thus, the study demonstrates the effective and non-toxic synthesis of AgNPs using a less explored lichen extract as a promising anticandida and anticancer agent in the field of nano-medicine.

scholarly journals Enhanced antibacterial activity through silver nanoparticles deposited onto carboxylated graphene oxide surface

2021 ◽  
Author(s):  
Arturo Barjola ◽  
María Ángeles Tormo ◽  
Oscar Sahuquillo ◽  
Patricia Bernabé ◽  
José Manuel Pérez ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Graphene Oxide ◽  
Biofilm Formation ◽  
Material Surface ◽  
Oxide Surface ◽  
Main Role ◽  
Carboxylic Groups ◽  
Average Size

Abstract The strong bactericidal action of silver nanoparticles (AgNPs) is usually limited for their degree of aggregation. Deposition of AgNPs onto a graphene oxide (GO) surface to generate GO-Ag hybrids has been shown to be an effective method to control these aggregation problems. In this sense, a novel carboxylated graphene oxide-silver nanoparticle (GOCOOH-Ag) material has been synthesized and their antibacterial and biofilm formation inhibition have been studied.AgNPs decorating the GOCOOH surface achieved an average size of 6.74±0.25 nm, which was smaller than those of AgNPs deposited onto the GO surface. In addition, better distribution of AgNPs was obtained using carboxylated material. It is important to highlight the main role of the carboxylic groups in the nucleation and growth of the AgNPs that decorate the GO-based material surface.In vitro antibacterial activity and antibiofilm-forming action were tested against Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli). Both GO-Ag and GOCOOH-Ag reduced the bacterial growth, analyzed by time-kill curves. However, the minimum inhibitory concentration and the minimum bactericidal concentration of GOCOOH-Ag were lower than those of GO-Ag for all strains studied, indicating that GOCOOH-Ag has better antibacterial activity. In addition, both nanomaterials prevent biofilm-formation, with a higher reduction of biofilm mass and cell viability in the presence of GOCOOH-Ag. The carboxylation functionalization in GO-based materials can be applied to improve the bactericidal and antibiofilm-forming action of the AgNPs.

scholarly journals Hyaluronic Acid Derivative Molecular Weight-Dependent Synthesis and Antimicrobial Effect of Hybrid Silver Nanoparticles

2021 ◽  
Vol 22 (24) ◽  
pp. 13428
Author(s):  
Guillem Ferreres ◽  
Sílvia Pérez-Rafael ◽  
Juan Torrent-Burgués ◽  
Tzanko Tzanov
Keyword(s):  
Molecular Weight ◽  
Silver Nanoparticles ◽  
Hyaluronic Acid ◽  
Mammalian Cells ◽  
Antimicrobial Effect ◽  
Mechanistic Study ◽  
Ag Nps ◽  
Antimicrobial Function ◽  
Reduced Toxicity

Silver nanoparticles (Ag NPs) appeared as promising antimicrobial candidates to face the development of antibiotic resistance. Although reported as toxic towards mammalian cells, their combination with biomolecules have shown reduced toxicity, while maintaining the antimicrobial function. Herein, hyaluronic acid (HA) with low (40 kDa), medium (200 and 600 kDa) and high (2 MDa) molecular weight (Mw) was modified with adipic acid dihydrazide (ADH) and used as reducing and capping agents to synthesise antimicrobial hybrid Ag NPs. The Mw of the polymer played a crucial role in the morphology, size and antibacterial activity of the Ag NPs. The 600 and 200 kDa HA-ADH-Ag NPs were able to reduce the Escherichia coli and Staphylococcus aureus concentration by more than 3 logs, while the 40 kDa NPs reached ~2 logs reduction. The 2 MDa HA-ADH failed to form homogenous NPs with strong bactericidal activity. A mechanistic study of the interaction with a model bacterial membrane using Langmuir isotherms confirmed the greater interaction between bacteria and higher Mw polymers and the effect of the NP’s morphology. The nanocomposites low toxicity to human skin cells was demonstrated in vitro, showing more than 90% cell viability after incubation with the NPs.

scholarly journals Multifaceted Phytogenic Silver Nanoparticles by a Rare Insectivorous Plant Drosera Spatulata Labill Var.bakoensis and its Enhanced Antioxidant, Antibacterial, Antifungal and in Vitro Cytotoxic Studies

2021 ◽  
Author(s):  
Susmila Aparna Gaddam ◽  
Venkata Subbaiah Kotakadi ◽  
Gunasekhar. Kalavakunta ◽  
Josthna Penchalaneni ◽  
Varadarajulu Naidu Challagundla ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Radical Scavenging ◽  
Human Colon ◽  
Xrd Analysis ◽  
Antimicrobial Activities ◽  
Human Colon Cancer ◽  
Tem Analysis ◽  
Insectivorous Plant ◽  
Average Size

Abstract The current investigation highlights the green synthesis of silver nanoparticles (AgNPs) by the insectivorous plant Drosera spatulata Labill var.bakoensis, which is the first of its kind. The biosynthesized nanoparticles revealed a UV visible surface plasmon resonance (SPR) band at 427 nm. The natural phytoconstituents which reduce the monovalent silver were identified by FTIR. The particle size of the Ds-AgNPs was detected by the Nanoparticle size analyzer confirms that the average size of nanoparticles was around 23 ± 2 nm. Ds-AgNPs exhibit high stability because of their high negative zeta potential (-34.1 mV). AFM studies also revealed that the Ds-AgNPs were spherical in shape and average size ranges from 10 to 20 ± 5 nm. TEM analysis also revealed that the average size of Ds-AgNPs was also around 21 ± 4 nm and the shape is roughly spherical and well dispersed. The crystal nature of Ds-AgNPs was detected as a face-centered cube by the XRD analysis. Furthermore, studies on antibacterial and antifungal activities manifested outstanding antimicrobial activities of Ds-AgNPs compared with standard antibiotic Amoxyclav. In addition, demonstration of superior free radical scavenging efficacy coupled with potential in vitro cytotoxic significance on Human colon cancer cell lines (HT-29) suggests that the Ds-AgNPs attain excellent multifunctional therapeutic applications.

In Vitro and In Vivo Antitumor Activity of Silver Nanoparticles on B16 Melanoma

NANO ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. 2050163
Author(s):  
Hongkun Gao ◽  
Ping Fan ◽  
Qizhen Xu ◽  
Yiting Li ◽  
Jianxin Wang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antitumor Activity ◽  
Antimicrobial Agents ◽  
Malignant Tumors ◽  
Annexin V ◽  
In Vitro Study ◽  
B16 Melanoma ◽  
Potential Strategy

Melanoma, one of the most malignant tumors, is difficult to treat due to its high drug resistance. Silver nanoparticles (AgNPs) are widely used as antimicrobial agents in biomedical fields. In this study, the spherical AgNPs with average sizes of 5[Formula: see text]nm were prepared using a dopamine reduction method. The in vitro study shows that AgNPs with the concentrations of 0.5[Formula: see text][Formula: see text]g/mL and 1[Formula: see text][Formula: see text]g/mL exhibit good biocompatibility to 3T3L1 fibroblast cells. AgNPs with the same concentrations significantly inhibited the growth of B16 melanoma cells. In culture with B16 cells, AgNPs induced intracellular oxidative stress by generating the reactive oxygen species and reducing the superoxide dismutase, which further reduces the mitochondrial membrane potential. Moreover, the damage in mitochondria could activate mitochondrion-mediated cell apoptosis. The B16 cells apoptosis was analyzed by FITC-Annexin V/propidium iodide double staining assay, which confirms that AgNPs caused the abundance of apoptotic cells in different stages. Thus, AgNPs displayed the antitumor activity in vitro. Then, the therapeutic efficacy in vivo was evaluated in mice-bearing B16 melanoma tumors. The obtained results show the antitumor ability of AgNPs and provide a potential strategy for cancer treatment.

In Vivo Effect of Different Doses of Silver Nanoparticles on the Seminiferous Tubules in Albino Rats: Histopathological Study

2020 ◽  
Vol 38 (1B) ◽  
pp. 1-5
Author(s):  
Ruqayah A. Salman ◽  
Abdulrahman K. Ali ◽  
Amenah Ali Salman
Keyword(s):  
Silver Nanoparticles ◽  
Harmful Effect ◽  
Seminiferous Tubules ◽  
Albino Rats ◽  
Histopathological Study ◽  
Ag Nps ◽  
Average Size ◽  
Different Doses

The study aims to investigate the effects of silver nanoparticles (Ag NPs) on the seminiferous tubules in Albino rats. Several in vitro studies have been performed in different cell models, using various nanoparticles. Pure and spherical AgNPs with an average size of 30 nm, was injected into two groups of male albino rats (6 rats for each group) in different doses. Histopathological changes in testis tissues were showed a harmful effect of the silver nanoparticles, manifested by reducing the number of spermatogenic cells, and a decrease in the number of leyidg´s cells (group 1), and hypotrophy in seminiferous and enlargement in interstitial spaces in group 2.

scholarly journals Synergy of Silver Nanoparticles and Aztreonam against Pseudomonas aeruginosa PAO1 Biofilms

2014 ◽  
Vol 58 (10) ◽  
pp. 5818-5830 ◽  
Author(s):  
Marc B. Habash ◽  
Amber J. Park ◽  
Emily C. Vis ◽  
Robert J. Harris ◽  
Cezar M. Khursigara
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Cell Envelope ◽  
Antimicrobial Properties ◽  
Planktonic Cell ◽  
Chronic Infections ◽  
Content Type

ABSTRACTPathogenic bacterial biofilms, such as those found in the lungs of patients with cystic fibrosis (CF), exhibit increased antimicrobial resistance, due in part to the inherent architecture of the biofilm community. The protection provided by the biofilm limits antimicrobial dispersion and penetration and reduces the efficacy of antibiotics that normally inhibit planktonic cell growth. Thus, alternative antimicrobial strategies are required to combat persistent infections. The antimicrobial properties of silver have been known for decades, but silver and silver-containing compounds have recently seen renewed interest as antimicrobial agents for treating bacterial infections. The goal of this study was to assess the efficacy of citrate-capped silver nanoparticles (AgNPs) of various sizes, alone and in combination with the monobactam antibiotic aztreonam, to inhibitPseudomonas aeruginosaPAO1 biofilms. Among the different sizes of AgNPs examined, 10-nm nanoparticles were most effective in inhibiting the recovery ofP. aeruginosabiofilm cultures and showed synergy of inhibition when combined with sub-MIC levels of aztreonam. Visualization of biofilms treated with combinations of 10-nm AgNPs and aztreonam indicated that the synergistic bactericidal effects are likely caused by better penetration of the small AgNPs into the biofilm matrix, which enhances the deleterious effects of aztreonam against the cell envelope ofP. aeruginosawithin the biofilms. These data suggest that small AgNPs synergistically enhance the antimicrobial effects of aztreonam againstP. aeruginosain vitro, and they reveal a potential role for combinations of small AgNPs and antibiotics in treating patients with chronic infections.

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