scholarly journals Exploitation of endophytic fungus, Guignardia mangiferae for extracellular synthesis of silver nanoparticles and their in vitro biological activities

2015 ◽  
Vol 178 ◽  
pp. 9-17 ◽  
Author(s):  
M.D. Balakumaran ◽  
R. Ramachandran ◽  
P.T. Kalaichelvan
AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hend M. Tag ◽  
Amna A. Saddiq ◽  
Monagi Alkinani ◽  
Nashwa Hagagy

AbstractHaloferax sp strain NRS1 (MT967913) was isolated from a solar saltern on the southern coast of the Red Sea, Jeddah, Saudi Arabia. The present study was designed for estimate the potential capacity of the Haloferax sp strain NRS1 to synthesize (silver nanoparticles) AgNPs. Biological activities such as thrombolysis and cytotoxicity of biosynthesized AgNPs were evaluated. The characterization of silver nanoparticles biosynthesized by Haloferax sp (Hfx-AgNPs) was analyzed using UV–vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The dark brown color of the Hfx-AgNPs colloidal showed maximum absorbance at 458 nm. TEM image analysis revealed that the shape of the Hfx-AgNPs was spherical and a size range was 5.77- 73.14 nm. The XRD spectra showed a crystallographic plane of silver nanoparticles, with a crystalline size of 29.28 nm. The prominent FTIR peaks obtained at 3281, 1644 and 1250 cm− 1 identified the Functional groups involved in the reduction of silver ion reduction to AgNPs. Zeta potential results revealed a negative surface charge and stability of Hfx-AgNPs. Colloidal solution of Hfx-AgNPs with concentrations ranging from 3.125 to 100 μg/mL was used to determine its hemolytic activity. Less than 12.5 μg/mL of tested agent showed no hemolysis with high significant decrease compared with positive control, which confirms that Hfx-AgNPs are considered non-hemolytic (non-toxic) agents according to the ISO/TR 7405-1984(f) protocol. Thrombolysis activity of Hfx-AgNPs was observed in a concentration-dependent manner. Further, Hfx-AgNPs may be considered a promising lead compound for the pharmacological industry.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 341
Author(s):  
Islam Lashin ◽  
Amr Fouda ◽  
Adil A. Gobouri ◽  
Ehab Azab ◽  
Zuhair M. Mohammedsaleh ◽  
...  

The in vitro callus induction of Solanum incanum L. was executed on MS medium supplemented with different concentrations of auxin and cytokinin utilizing petioles and explants of leaves. The highest significant fresh weights from petioles and leaf explants were 4.68 and 5.13 g/jar for the medium supplemented with1.0 mg L−1 BA and 1.0 mg L−1 2,4-D. The callus extract of the leaves was used for the green synthesis of silver nanoparticles (Ag-NPs). Analytical methods used for Ag-NPs characterization were UV-vis spectroscopy, Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and Transmission Electron Microscopy (TEM). Spherical, crystallographic Ag-NPs with sizes ranging from 15 to 60nm were successfully formed. The FT-IR spectra exhibited the role of the metabolites involved in callus extract in reducing and capping Ag-NPs. The biological activities of Ag-NPs were dose-dependent. The MIC value for Staphylococcus aureus, Bacillus subtilis, and Escherichia coli was 12.5 µg mL−1, while it was 6.25 µg mL−1 for Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans. The highest inhibition of phytopathogenic fungi Alternaria alternata, Fusarium oxysporum, Aspergillus niger, and Pythium ultimum was 76.3 ± 3.7, 88.9 ± 4.1, 67.8 ± 2.1, and 76.4 ± 1.0%, respectively at 200 µg mL−1. Moreover, green synthesized Ag-NPs showed cytotoxic efficacy against cancerous cell lines HepG2, MCF-7 and normal Vero cell line with IC50 values of 21.76 ± 0.56, 50.19 ± 1.71, and 129.9 ± 0.94 µg mL−1, respectively.


Author(s):  
Walid A. Lotfy ◽  
Basma M. Alkersh ◽  
Soraya A. Sabry ◽  
Hanan A. Ghozlan

In this study, mycelial filtrate of Aspergillus terreus BA6 was used to reduce AgNO3 to form silver nanoparticles (AgNPs). The effect of seven independent variables on the diameter of AgNPs was studied by applying design of experiments (DOE). At optimal conditions, the diameter of AgNPs was reduced by approximately 26.7% compared to the basal culture condition and AgNO3 concentration was found to be the most significant factor affecting the diameter of AgNPs. A. terreus nano-Ag was characterized using UV-visible spectroscopy, transmission electron microscopy, energy dispersive X-ray (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Zeta potential. The maximum UV absorption was obtained at 420 nm and the microscopic results showed particles with narrow size distribution ranging from 7 to 23 nm. XRD pattern of AgNPs revealed four diffraction peaks of metallic silver and the EDX spectrum showed a strong signal attributed to Ag nano-crystals. AgNPs mycofabricated by A. terreus showed potent minimum inhibitory concentration (MIC) and broad minimum bactericidal/fungicidal concentration (MBC/MFC) against 12 reference microorganisms. The MIC and MBC/MFC values of AgNPs were 0.312 to 1.25 μg/ml and 0.625 to 10 μg/ml, respectively. Nevertheless, AgNPs did not demonstrate any antagonistic activity against Coxsackie B virus. The in vitro cytotoxicity of the mycosynthesized AgNPs showed significant antitumor activity against adenocarcinoma epithelial cells from human breast cancer (Mcf-7) cell line with an inhibitory concentration (IC50) of 87.5 μg/ml.


Author(s):  
Abdelmageed M. Othman ◽  
Maysa A. Elsayed ◽  
Naser G. Al-Balakocy ◽  
Mohamed M. Hassan ◽  
Ali M. Elshafei

Abstract Background The present study aims to apply an efficient eco-friendly and inexpensive process for green synthesis of silver nanoparticles (AgNPs) through the mediation of fungal proteins from Aspergillus fumigatus DSM819, characterization, and its application as antimicrobial finishing agent in textile fabrics against some infectious microorganisms. Results Optimum conditions for AgNP biosynthesis could be achieved by means of using 60% (v/v) of cell-free filtrate (CFF) and 1.5 mM of AgNO3 at pH 10.0 after 90 min. The obtained AgNPs were of spherical shape with 90% of distribution below than 84.4 nm. The biosynthesized AgNPs exerted an antimicrobial activity against the studied pathogenic microorganisms (E. coli, B. mycoides, and C. albicans). In addition, IC50 values against in vitro tumor cell lines were found to be 31.1, 45.4, 40.9, and 33.5 μg/ml for HCT116, A549, MCF7, and PC3, respectively. Even with a very low concentration (0.25%), the treated PET/C fabrics by AgNPs exerted an antimicrobial activity against E. coli, B. mycoides, and C. albicans to give inhibition zone diameter of 15, 15, and 16 mm, respectively. Conclusions The green biosynthesis approach applied in this study is a non-toxic alternative to the traditional chemical and physical methods, and would be appropriate for biological large-scale production and prospective treatments. Graphical abstract


2021 ◽  
Vol 22 (16) ◽  
pp. 8673
Author(s):  
Andrea Rónavári ◽  
Péter Bélteky ◽  
Eszter Boka ◽  
Dalma Zakupszky ◽  
Nóra Igaz ◽  
...  

(1) Background: Several properties of silver nanoparticles (AgNPs), such as cytotoxic, anticancer, and antimicrobial activities, have been subjects of intense research; however, important aspects such as nanoparticle aggregation are generally neglected, although a decline in colloidal stability leads to a loss of the desired biological activities. Colloidal stability is affected by pH, ionic strength, or a plethora of biomolecules that interact with AgNPs under biorelevant conditions. (2) Methods: As only a few studies have focused on the relationship between aggregation behavior and the biological properties of AgNPs, here, we have systematically evaluated this issue by completing a thorough analysis of sterically (via polyvinyl-pyrrolidone (PVP)) stabilized AgNPs that were subjected to different circumstances. We assessed ultraviolet–visible light absorption, dynamic light scattering, zeta potential measurements, in vitro cell viability, and microdilution assays to screen both colloidal stability as well as bioactivity. (3) Results: The results revealed that although PVP provided outstanding biorelevant colloidal stability, the chemical stability of AgNPs could not be maintained completely with this capping material. (4) Conclusion: These unexpected findings led to the realization that stabilizing materials have more profound importance in association with biorelevant applications of nanomaterials than just being simple colloidal stabilizers.


Author(s):  
Laureen Michelle Houllou ◽  
Robson Antonio Barbosa De Souza ◽  
Carolina Barbosa Malafaia ◽  
Débora Lorrane Montenegro da Paixão ◽  
Alisson Tito Bezerra de Araújo ◽  
...  

Metal nanoparticles are nanostructures that can be applied to biotechnology because they present different biological activities. Among them, the silver nanoparticles (AgNPs) are known to present antimicrobial activity allowing their application in several areas such as medicine and industry. The biological synthesis of AgNPs is ecologically correct and advantageous techniques. The objective of this work was to evaluate the synthesis of AgNps through the green synthesis using extracts of leaves of Tabebuia roseoalba and T. pentaphylla grown in vivo and in vitro. The nanoparticle synthesis solution was colorimetrically evaluated, and the nanoparticles were physically characterized. The results obtained demonstrate that both extracts of both Tabebuia species tested are able to synthesize AgNPs, however only when cultured under in vivo conditions. These data suggest that photosynthesis under natural conditions promotes the production of metabolites that are essential to green synthesis.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8142 ◽  
Author(s):  
Yuridia Torres-Martínez ◽  
Eder Arredondo-Espinoza ◽  
Carlos Puente ◽  
Omar González-Santiago ◽  
Nayely Pineda-Aguilar ◽  
...  

In this study, silver nanoparticles (NP) were synthesized by two methods: using an aqueous extract of Mentha spicata leaves and using citrate ions as stabilizing agent, and the cytotoxicity and anticancer activity of both NP were evaluated in vitro. The particles synthesized with the aqueous extract were spherical with a size ranging from 15 to 45 nm. These NP decreased cell viability in all of the cells studied; however, the IC50 could only be estimated in the Chang liver cells (IC50 = 21.37 µg/mL). These particles also decreased the generation of reactive oxygen species in Chang and SiHa cells. Additionally, the dispersions decreased the activity of caspase-3. There was no significant difference between the biological activities of the NP obtained with the aqueous extract and the NP synthesized using citrate ions. This study showed that an aqueous extract of M. spicata is an excellent alternative for the synthesis of silver NP. These NP showed cytotoxicity and anticancer activity in vitro. Although more experiments are required, the cell death occurs probably through a mechanism different from apoptosis.


2014 ◽  
Vol 2 ◽  
pp. 194308921350703 ◽  
Author(s):  
N. Muniyappan ◽  
N. S. Nagarajan

Silver nanoparticles (AgNPs) synthesized are utilized in drugs because of their pharmacological and biomedical applications and also due to their ecofriendly properties. In the present study, stable AgNPs have been synthesized from the aqueous extract of Dalbergia rostrata stem bark (DRSB), which is used both as a reducing and as a stabilizing agent. The AgNPs synthesized by ultrasonication at 25°C for 10 min were found to be stable in aqueous solution at room temperature over a period of 3 months. The quantitatively stable AgNPs formed by treating the aqueous solution of AgNO3 with the aqueous extract of the plant by reduction of Ag+ ions when monitored by UV–visible spectroscopic study revealed the surface plasmon resonance (SPR) at 425 nm. According to transmission electron micrography, the NPs were spherical and in the size range of 14 ± 4 nm. When evaluated for their anti-inflammatory and antioxidant activity by in vitro methods, AgNPs showed considerably enhanced activity compared to DRSB aqueous extract.


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