In vitro mutagenic and anti‐mutagenic properties of green synthesised silver nanoparticles

This study is aimed at determining the mutagenic and anti‐mutagenic properties of silver nanoparticles (AgNPs) biosynthesised from Streptomyces griseorubens AU2. To the authors’ knowledge, this is the first study about the investigation of these properties for biogenic AgNPs bacterially synthesised. The mutagenic and anti‐mutagenic potencies were determined by the Ames Salmonella /microsome mutagenicity test using Salmonella typhimurium TA98 and TA100 strains. After determining the cytotoxic dose of green synthesised AgNPs against S. typhimurium TA98 and TA100 strains, subcytotoxic doses (250, 100 and 50 µg/plate) were used in the assays. Biogenic AgNPs at the tested concentrations exhibited no mutagenic effects in the mutagenicity test conducted with the test strains. Moderate anti‐mutagenic effects were observed at high test concentrations. The concentration of 250 µg/plate showed the strongest anti‐mutagenic activity on S. typhimurium TA98. The results did not indicate any mutagenic effect against either of the strains used for screening the mutagenicity of the biogenic AgNPs as they were found to be genotoxically safe. It can be concluded that biogenic AgNPs showed great anti‐mutagenic attributes, standing as a significant factor with respect to medical, pharmaceutical and cosmetic industries.Inspec keywords: biomedical materials, microorganisms, nanomedicine, nanoparticles, silver, toxicologyOther keywords: in vitro mutagenic properties, in vitro antimutagenic properties, green synthesised silver nanoparticles, Streptomyces griseorubens AU2, biogenic silver nanoparticle biosynthesis, microsome mutagenicity test, Salmonella typhimurium TA98 strains, Salmonella typhimurium TA100 strains, subcytotoxic doses, medical industries, pharmaceutical industries, cosmetic industries, Ag     

Starch‐capped sulphur nanoparticles synthesised from bulk powder sulphur and their anti‐phytopathogenic activity against Clavibacter sepedonicus

Water‐soluble, stable nanoparticles of elemental sulphur with a size of 9‐52 nm have been synthesised using the stabilising potential of starch. Sulphide anions were used as sulphur precursors that were generated earlier from the bulk powder sulphur in the base‐reduction system NaOH‐N₂H₄·H₂O followed by their oxidation with molecular oxygen to element sulphur atoms. Using a set of modern spectral and microscopic methods (XRD, optical spectroscopy, DLS, TEM), the phase state, elemental composition of the nanocomposites and their nanomorphological characteristics have been investigated. It was found that nanocomposites are formed as sulphur particles with the shape which is nearly spherical dispersed in the polysaccharide starch matrix with a pronounced tendency to cluster into ring formations. Water solubility and stability of the obtained nanoparticles is ensured by sorption of starch macromolecules on the surface of sulphur nanoparticles, with the thickness of the stabilising shell in a range of 10‐171 nm. In vitro experiments were carried out to study the anti‐microbial activity of the obtained sulphur nanocomposite (1.6% S) using the propidium iodide fluorescent dye staining method and the diffusion method. It showed that the water solution of the starch‐capped sulphur nanoparticles at the concentration of 6.25 µg/ml had a pronounced anti‐phytopathogenic activity against the potato ring rot pathogen Clavibacter michiganensis subsp. sepedonicus.     

Removal of toxic contaminants from water by sustainable green synthesised non‐toxic silver nanoparticles

The study describes the synthesis of silver nanoparticles using 21 different plant extracts having medicinal properties. Molecular ultraviolet‐visible spectroscopy shows that the λ _max of nanoparticles synthesised by different plant extracts varied and ranged between 400 and 468 nm. The ultraviolet results revealed that although synthesis of nanoparticles occurred by all plant extracts successfully, their size varies, this was further confirmed by differential light scattering. The synthesised nanoparticles were investigated for their antimicrobial properties. The most promising silver nanoparticles Ocimum sanctum and Artemisia annua assisted were further characterised using transmission electron microscopy and energy dispersive X‐ray spectroscopy (EDX). EDX data confirms that synthesised nanoparticles are highly pure. Further these two plant assisted nanoparticles were studied for chemocatalytic and adsorptive properties. The silver nanoparticles from Ocimum sanctum can catalyse the reduction of 4‐nitrophenol (63%) within 20 min in the presence of NaBH₄, whereas Artemisia annua assisted silver nanoparticles did not show significant chemocatalytic activity. Both the promising nanoparticles can efficiently adsorb textile dyes from aqueous solutions. These synthesised nanoparticles were also exploited to remove microbial and other contaminants from Yamuna River water. The nanoparticles show excellent antimicrobial properties and can be reused repeatedly.Inspec keywords: antibacterial activity, nanofabrication, silver, dyes, light scattering, visible spectra, microorganisms, X‐ray diffraction, transmission electron microscopy, X‐ray chemical analysis, catalysis, nanoparticles, ultraviolet spectra, adsorption, reduction (chemical)Other keywords: sustainable green synthesised nontoxic silver nanoparticles, silver nitrate, molecular ultraviolet–visible spectroscopy, plant assisted nanoparticles, plant extracts, Ocimum sanctum, Artemisia annua, E. coli, C. albicans, plasmon absorbance, differential light scattering, energy dispersive X‐ray spectroscopy, 4‐nitrophenol, chemocatalytic activity, Yamuna River water, antimicrobial properties, time 20.0 min, time 5.0 min to 240.0 hour, size 1.0 nm to 5.0 nm, size 5.0 nm to 20.0 nm, wavelength 400.0 nm to 468.0 nm, NaBH₄ , Ag     

Evaluation of betamethasone sodium phosphate loaded chitosan nanoparticles for anti‐rheumatoid activity

Nanocarriers, in various forms, have the possibility of providing endless opportunities in the area of drug delivery. The purpose of this study was formulation and evaluation of betamethasone sodium phosphate (BSP) loaded chitosan nanoparticles (CNPs) using cross‐linked chitosan malic acid derivative for better therapeutic effect. The prepared BSP loaded CNPs formulations were characterised for photon correlation spectroscopy, zeta potential, transmission electron microscopy, in‐vitro release kinetics and in‐vivo toxicity studies. Mean particle diameter of BSP loaded CNPs was about 130 nm with spherical morphology. The in‐vitro drug release study of BSP loaded CNPs showed sustained drug release for 48 h and drug release was found to follow zero order. The biochemical, haematology and histopathology reports of in‐vivo toxicity studies revealed that BSP loaded CNPs do not exhibit any toxic effect on vital organs and could be safe. The developed BSP loaded CNPs are found to be safer, and used for the treatments of highly prevalent and chronic disease like rheumatoid arthritis.Inspec keywords: nanoparticles, drug delivery systems, electrokinetic effects, toxicology, photon correlation spectroscopy, transmission electron microscopy, diseases, organic compounds, nanomedicineOther keywords: betamethasone sodium phosphate, chitosan nanoparticles, antirheumatoid activity, nanocarriers, drug delivery, cross‐linked chitosan malic acid derivative, photon correlation spectroscopy, zeta potential, transmission electron microscopy, in‐vitro release kinetics, in‐vivo toxicity, spherical morphology, rheumatoid arthritis     

Phyto‐assisted synthesis of bio‐functionalised silver nanoparticles and their potential anti‐oxidant,anti‐microbial and wound healing activities

Bio‐ synthesis of silver nanoparticles (AgNPs) was made by using the aqueous leaf extract of Ardisia solanacea. Rapid formation of AgNPs was observed from silver nitrate upon treatment with the aqueous extract of A. solanacea leaf. The formation and stability of the AgNPs in the colloidal solution were monitored by UV–visible spectrophotometer. The mean particle diameter of AgNPs was calculated from the DLS with an average size ∼4 nm and ∼65 nm. ATR‐FTIR spectroscopy confirmed the presence of alcohols, aldehydes, flavonoids, phenols and nitro compounds in the leaf which act as the stabilizing agent. Antimicrobial activity of the synthesized AgNPs was performed using agar well diffusion and broth dilution method against the Gram‐positive and Gram‐negative bacteria. Further, robust anti‐oxidative potential was evaluated by DPPH assay. The highest antimicrobial activity of synthesized AgNPs was found against Pseudomonas aeruginosa (28.2 ± 0.52 mm) whereas moderate activity was found against Bacillus subtilis (16.1 ± 0.76), Candida kruseii (13.0 ± 1.0), and Trichophyton mentagrophytes (12.6 ± 1.52). Moreover, the potential wound healing activity was observed against the BJ‐5Ta normal fibroblast cell line. Current research revealed that A. solanacea was found to be a suitable source for the green synthesis of silver nanoparticles.Inspec keywords: antibacterial activity, nanoparticles, silver, nanomedicine, wounds, microorganisms, X‐ray diffraction, ultraviolet spectra, visible spectra, Fourier transform infrared spectra, transmission electron microscopyOther keywords: phyto‐assisted synthesis, biofunctionalised silver nanoparticles, antioxidant antimicrobial wound healing activities, silver nanoparticle biosynthesis, aqueous leaf extract, Ardisia solanacea, silver nitrate, UV–visible spectroscopy, dynamic light scattering, Fourier transform infra‐red spectroscopy, X‐ray diffraction, electron microscopy, attenuated total reflection Fourier transform infra‐red spectroscopy, dilution method, Gram‐positive bacteria, Gram‐negative bacteria, radical scavenging method, Pseudomonas aeruginosa, Trichophyton mentagrophytes, Bacillus subtilis, Candida kruseii, BJ‐5Ta normal fibroblast cell line, SEM, alcohols, aldehydes, flavonoids, phenols, nitro compounds, Ag     

Evaluation of antimicrobial activity of synthesised silver nanoparticles using Thymus kotschyanus aqueous extract

Development of a green chemistry process for the synthesis of silver nanoparticles (AgNPs) has become a focus of interest. Characteristics of AgNPs were determined using techniques, such as ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy and X‐ray diffraction (XRD). The synthesised AgNPs using Thymus kotschyanus had the most growth inhibition against gram‐positive bacteria such as Staphylococcus aureus and Bacillus subtilise, while the growth inhibition of AgNPs at 1000–500 µg/ml occurred against Klebsiella pneumonia and at 1000–250 µg/ml of AgNPs was observed against E. coli. The UV–vis absorption spectra confirmed the formation of the AgNPs with the characteristic peak at 415 nm and SEM micrograph acknowledged spherical particles in a nanosize range. FTIR measured the possible biomolecules that are responsible for stabilisation of AgNPs. XRD analysis exhibited the crystalline nature of AgNPs and showed face‐centred cubic structure. The synthesised AgNPs revealed significant antibacterial activity against gram‐positive bacteria.Inspec keywords: visible spectra, microorganisms, ultraviolet spectra, biomedical materials, nanofabrication, nanoparticles, X‐ray diffraction, scanning electron microscopy, molecular biophysics, X‐ray chemical analysis, nanomedicine, silver, antibacterial activity, Fourier transform infrared spectraOther keywords: green chemistry process, ultraviolet–visible spectroscopy, gram‐positive bacteria, silver nanoparticles, Thymus kotschyanus aqueous extract, UV–vis spectroscopy, Fourier transform infrared spectroscopy, FTIR analysis, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, SEM micrograph, X‐ray diffraction, XRD, Staphylococcus aureus, Bacillus subtilise, Klebsiella pneumonia, E. coli, UV–vis absorption spectra, face‐centred cubic structure, antibacterial activity, antimicrobial activity, wavelength 415.0 nm, Ag     

Sustainable green synthesis of silver nanoparticles by using Rangoon creeper leaves extract and their spectral analysis and anti‐bacterial studies

The plant‐based biological molecules possess exceptionally controlled assembling properties to make them suitable in the synthesis of metal nanoparticles. In the present study, an efficient simple one‐pot method was employed for the synthesis of silver nanoparticles (SNPs) from the Rangoon creeper (RC) aqueous leaf extract. Biomolecules present in the leaf extract play a significant role as reducing agent as well as capping agent in the formation of RC‐SNPs. The formation of RC‐SNPs was confirmed by using several analytical techniques such as Fourier‐transform infrared spectroscopy and ultraviolet–visible spectrophotometer studies. The presence of a sharp surface plasmon resonance peak at 449 nm showed the formation of RC‐SNPs. X‐ray diffraction analysis showed the crystalline nature of the RC‐SNPs with a face‐centred cubic structure. Elemental analysis of RC‐SNPs was done by using energy‐dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy. The morphology of RC‐SNPs was examined by transmission electron microscopy (TEM) in the nano range 12 nm, and thermogravimetric‐differential thermal analysis demonstrated the mechanical strength of RC‐SNPs at various temperatures. The authors’ newly synthesised RC‐SNPs exhibited significant anti‐bacterial activity against Staphylococcus aureus and Escherichia coli. Inspec keywords: silver, nanoparticles, X‐ray photoelectron spectra, antibacterial activity, ultraviolet spectra, microorganisms, X‐ray chemical analysis, differential thermal analysis, X‐ray diffraction, transmission electron microscopy, visible spectra, nanofabrication, surface plasmon resonance, Fourier transform infrared spectra, mechanical strengthOther keywords: silver nanoparticles, ultraviolet–visible spectrophotometry, antibacterial activity, sustainable green synthesis, plant‐based biological molecules, assembling properties, reducing agent, capping agent, Fourier‐transform infrared spectroscopy, surface plasmon resonance, Rangoon creeper aqueous leaf extract, X‐ray diffraction, face‐centred cubic structure, elemental analysis, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy, transmission electron microscopy, TEM, thermogravimetric‐differential thermal analysis, mechanical strength, Staphylococcus aureus, Escherichia coli, Ag     

Characterisation and antifungal activity of silver nanoparticles biologically synthesised by Amaranthus retroflexus leaf extract

ABSTRACT

Following the emergence of resistant fungal pathogens, silver nanoparticles (AgNPs) biosynthesized by plants have been recognized as promising tools to combat parasitic fungi. This study evaluated the potency of Amaranthus retroflexus in producing AgNPs, followed by testing their antifungal effects. The AgNPs exhibited a maximum absorption at 430 nm through ultraviolet-visible spectroscopy, while the X-ray diffraction indicated that they were crystal in nature. Fourier transform infrared spectroscopy confirmed the conversion of Ag⁺ ions to AgNPs due to the reduction by capping material of plant extract. The transmission electron microscope analysis further revealed that the AgNPs were spherical ranging from 10 nm to 32 nm in size. The AgNPs at the concentrations of 50, 100, 200, and 400 μg/mL were applied to the growth of plant, mushroom, and human pathogenic fungi. The 50% minimum inhibitory concentrations (MIC₅₀) against Macrophomina phaseolina, Alternaria alternata and Fusarium oxysporum were observed to be 159.80 ± 14.49, 337.09 ± 19.72, and 328.05 ± 13.29 μg/mL, respectively. However, no considerable inhibition was observed regarding Trichoderma harzianum or Geotrichum candidum. These findings may suggest A. retroflexus as a green solution for biosynthesizing AgNPs with potent antifungal activities against plant pathogenic fungi.     

Evaluation of the toxicities of silver and silver sulfide nanoparticles against Gram‐positive and Gram‐negative bacteria

In this study, the endogenous lipid signalling molecules, N ‐myristoylethanolamine, were explored as a capping agent to synthesise stable silver nanoparticles (AgNPs) and Ag sulphide NPs (Ag₂ S NPs). Sulphidation of the AgNPs abolishes the surface plasmon resonance (SPR) maximum of AgNPs at 415 nm with concomitant changes in the SPR, indicating the formation of Ag₂ S NPs. Transmission electron microscopy revealed that the AgNPs and Ag₂ S NPs are spherical in shape with a size of 5–30 and 8–30 nm, respectively. AgNPs and Ag₂ S NPs exhibit antimicrobial activity against Gram‐positive and Gram‐negative bacteria. The minimum inhibitory concentrations (MIC) of 25 and 50 μM for AgNPs and Ag₂ S NPs, respectively, were determined from resazurin microtitre plate assay. At or above MIC, both AgNPs and Ag₂ S NPs decrease the cell viability through the mechanism of membrane damage and generation of excess reactive oxygen species.Inspec keywords: cellular biophysics, biomembranes, transmission electron microscopy, nanomedicine, microorganisms, molecular biophysics, antibacterial activity, nanofabrication, silver, biomedical materials, surface plasmon resonance, nanoparticles, materials preparation, silver compounds, lipid bilayersOther keywords: Gram‐negative bacteria, Gram‐positive bacteria, endogenous lipid signalling molecules, N‐myristoylethanolamine, capping agent, silver nanoparticles, Ag sulphide NPs, sulphidation, surface plasmon resonance, concomitant changes, transmission electron microscopy, minimum inhibitory concentrations, resazurin microtitre plate assay, cell viability, membrane damage, reactive oxygen species, Ag toxicities, Ag, Ag₂ S     

Ecotoxicity of as‐synthesised copper nanoparticles on soil bacteria

Release of metallic nanoparticles in soil poses a serious threat to the ecosystem as they can affect the soil properties and impose toxicity on soil microbes that are involved in the biogeochemical cycling. In this work, in vitro ecotoxicity of as‐synthesised copper nanoparticles (CuNPs) on Bacillus subtilis (MTCC No. 441) and Pseudomonas fluorescens (MTCC No. 1749), which are commonly present in soil was investigated. Three sets of colloidal CuNPs with identical physical properties were synthesised by chemical reduction method with per batch yield of 0.2, 0.3 and 0.4 gm. Toxicity of CuNPs against these soil bacteria was investigated by MIC (minimum inhibitory concentration), MBC (minimum bactericidal concentration), cytoplasmic leakage and ROS (reactive oxygen species) assay. MIC of CuNPs were in the range of 35–60 µg/ml and 35–55 µg/ml for B. subtilis and P. fluorescens respectively, while their MBC ranged from 40–70 µg/ml and 40–60 µg/ml respectively. MIC and MBC tests reveal that Gram‐negative P. fluorescens was more sensitive to CuNPs as compared to Gram positive B. subtilis mainly due to the differences in their cell wall structure and composition. CuNPs with smaller hydrodynamic size (11.34 nm) were highly toxic as revealed by MIC, MBC tests, cytoplasmic leakage and ROS assays, which may be due to the higher active surface area of CuNPs and greater membrane penetration. Leakage of cytoplasmic components and generation of extra‐cellular oxidative stress by reactive oxygen species (ROS) causes cell death. The present study realizes in gauging the negative impact of inadvertent release of nanoparticles in the environment, however, in situ experiments to know its overall impact on soil health and soil microflora can help in finding solution to combat ecotoxicity of nanoparticles.     

Synthesis,characterisation and anti‐tumour activity of biopolymer based platinum nanoparticles and 5‐fluorouracil loaded platinum nanoparticles

A facile and green synthesis of platinum nanoparticles [gum kondagogu platinum nanoparticles (GKPtNP)] using biopolymer‐ gum kondagogu was developed. The formation of GKPtNP was confirmed by ultraviolet (UV)–visible spectroscopy, scanning electron microscopy–energy dispersive X‐ray spectroscopy, transmission electron microscopy, X‐ray diffraction, Zeta potential, Fourier transform infrared, inductively coupled plasma mass spectroscopy. The formed GKPtNP are well dispersed, homogeneous with a size of 2–4 ± 0.50 nm, having a negative zeta potential (−46.1 mV) indicating good stability. 5‐Fluorouracil (5FU) was loaded onto the synthesised GKPtNP, which leads to the development of a new combination of nanomedicine (5FU–GKPtNP). The in vitro drug release studies of 5FU–GKPtNP in pH 7.4 showed a sustained release profile over a period of 120 min. Agrobacterium tumefaciens induced in vitro potato tumour bioassay was employed for screening the anti‐tumour potentials of GKPtNP, 5FU, and 5FU–GKPtNP. The experimental results suggested a complete tumour inhibition by 5FU–GKPtNP at a lower concentration than the GKPtNP and 5FU. Furthermore, the mechanism of anti‐tumour activity was assessed by their interactions with DNA using agarose gel electrophoresis and UV‐spectroscopic analysis. The electrophoresis results revealed that the 5FU–GKPtNP totally diminishes DNA and the UV‐spectroscopic analysis showed a hyperchromic effect with red shift indicating intercalation type of binding with DNA. Over all, the present study revealed that the combined exposure of the nanoformulation resulted in the enhanced anti‐tumour effect. Inspec keywords: nanoparticles, transmission electron microscopy, biomedical materials, tumours, ultraviolet spectra, DNA, drugs, electrophoresis, polymers, platinum, pH, drug delivery systems, biochemistry, X‐ray chemical analysis, microorganisms, molecular biophysics, electrokinetic effects, X‐ray diffraction, scanning electron microscopy, cancer, nanofabrication, visible spectra, nanomedicine, Fourier transform infrared spectra, materials preparationOther keywords: 5FU–GKPtNP, 5‐fluorouracil loaded platinum nanoparticles, gum kondagogu platinum nanoparticles, antitumour activity, scanning electron microscopy‐energy dispersive X‐ray spectroscopy, biopolymer‐based platinum nanoparticles, biopolymer‐based platinum nanoparticles, ultraviolet‐visible spectroscopy, UV‐visible spectroscopy, transmission electron microscopy, X‐ray diffraction, zeta potential, Fourier transform infrared spectroscopy, inductively coupled plasma mass spectroscopy, nanomedicine, in vitro drug release studies, sustained release profile, Agrobacterium tumefaciens, in vitro potato tumour bioassay, tumour inhibition, tumour activity, agarose gel electrophoresis, UV‐spectroscopic analysis, DNA, time 120.0 min, Pt     

Antimicrobial potential and in vitro cytotoxicity study of polyvinyl pyrollidone‐stabilised silver nanoparticles synthesised from Lysinibacillus boronitolerans

The main emphasis herein is on the eco‐friendly synthesis and assessment of the antimicrobial potential of silver nanoparticles (AgNPs) and a cytotoxicity study. Silver nanoparticles were synthesised by an extracellular method using bacterial supernatant. Biosynthesised silver nanoparticles were characterised by UV‐vis spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, dynamic light scattering, and zeta potential analysis. The synthesised silver nanoparticles exhibited a characteristic peak at 420 nm. TEM analysis depicted the spherical shape and approximately 20 nm size of nanoparticles. Silver nanoparticles carry a charge of −33.75 mV, which confirms their stability. Biogenic polyvinyl pyrrolidone‐coated AgNPs exhibited significant antimicrobial effects against all opportunistic pathogens (Gram‐positive and Gram‐negative bacteria, and fungi). Silver nanoparticles equally affect the growth of both Gram‐positive and Gram‐negative bacteria, with a maximum inhibition zone observed at 22 mm and a minimum at 13 mm against Pseudomonas aeruginosa and Fusarium graminearum, respectively. The minimum inhibitory concentration (MIC) of AgNPs against P. aeruginosa and Staphylococcus aureus was recorded at between 15 and 20 μg/ml. Synthesised nanoparticles exhibited a significant synergistic effect in combination with conventional antibiotics. Cytotoxicity estimates using C2C12 skeletal muscle cell line via 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) test and lactate dehydrogenase assay were directly related to the concentration of AgNPs and length of exposure. On the basis of the MTT test, the IC50 of AgNPs for the C2C12 cell line was approximately 5.45 μg/ml concentration after 4 h exposure.     

Antibacterial and dye degradation potential of zero‐valent silver nanoparticles synthesised using the leaf extract of Spondias dulcis

The present study reports a simple and low cost synthesis of zero‐valent silver nanoparticles (ZVSNPs) from silver nitrate using the leaf extract of Spondias dulcis. The ZVSNPs showed a unique peak at 420 nm in UV–vis spectrum. The SEM image portrayed cuboidal shaped particles. The EDX spectrum designated the elemental silver peak at 3 keV. In XRD, a sharp peak at 32.47° denoted the existence of (1 0 1) lattice plane and the average crystallite size was calculated as 48.61 nm. The lattice parameter was determined as 0.39 nm. The FTIR spectra of the leaf extract and ZVSNPs showed shifts in the specific functional group bands which ascertained the involvement of phytoconstituents in the formation and capping of nanoparticles. The average hydrodynamic size was measured as 59.66 nm by DLS method. A low PDI, 0.187 witnessed the monodispersity. A negative zeta potential value of −15.7 mV indicated the negative surface charges of the nanoparticles. The bactericidal action of ZVSNPs was demonstrated against two pathogens S.typhimurium and E.coli during which a dosage dependent zone of inhibition results was observed. Additionally, the catalytic potential of ZVSNPs was examined for the degradation of methylene blue dye in which an accelerated degradation of the dye was observed.Inspec keywords: antibacterial activity, crystallites, electrokinetic effects, scanning electron microscopy, nanoparticles, particle size, ultraviolet spectra, X‐ray chemical analysis, microorganisms, light scattering, nanofabrication, materials preparation, X‐ray diffraction, visible spectra, silver, dyes, Fourier transform infrared spectraOther keywords: wavelength 420.0 nm, Ag, voltage ‐15.7 mV, size 59.66 nm, size 0.39 nm, size 48.61 nm, electron volt energy 3.0 keV, Fourier transform infrared spectra, methylene blue dye, bactericidal action, dynamic light scattering, lattice parameter, Escherichia coli, Salmonella typhimurium, Spondias dulcis, negative zeta potential, polydispersity index, crystallite size, leaf extract, X‐ray diffraction, energy dispersive X‐ray spectrum, cuboidal‐shaped particles, scanning electron microscopy image, ultraviolet–visible spectrum, silver nitrate, zero‐valent silver nanoparticles     

Nutratherapeutics approach against cancer: tomato‐mediated synthesised gold nanoparticles

In this study, an eco‐friendly biosynthesis of stable gold nanoparticles (T‐GNPs) was carried out using different concentrations of tomato juice (nutraceuticals) as a reducing agent and tetrachloroauric acid as a metal precursor to explore their potential application in cancer therapeutics. The synthesis of T‐GNPs was monitored by UV‐visible absorption spectroscopy, which unveiled their formation by exhibiting the typical surface plasmon absorption maxima at 522 nm. The size of T‐GNPs was found to be 10.86 ± 0.6 nm. T‐GNPs were characterised by dynamic light scattering, zeta potential, transmission electron microscopy analysis and Fourier transform infrared spectroscopy. T‐GNPs were further investigated for their anti‐cancer activity against human lung carcinoma cell line (A ₅₄₉) and human cervical cancer cell line wherein the IC₅₀ values were found to be 0.286 and 0.200 mM, respectively. T‐GNPs inhibited the growth of cancer cells by generating ROS and inducing apoptosis. T‐GNPs were found highly effective by virtue of their size, metallic property and capping molecules. Thus, this study opens up the prospects of using nutraceutical (tomato juice) as nutratherapeutic agent (T‐GNPs) against critical diseases like lung cancer and cervical cancer.Inspec keywords: gold, nanoparticles, particle size, cancer, ultraviolet spectra, visible spectra, electrokinetic effects, transmission electron microscopy, Fourier transform infrared spectra, cellular biophysics, spectrochemical analysis, nanomedicine, nanofabricationOther keywords: tomato‐mediated synthesised gold nanoparticles, tomato juice, reducing agent, tetrachloroauric acid, cancer therapeutics, UV‐visible absorption spectroscopy, surface plasmon absorption, dynamic light scattering, zeta potential, transmission electron microscopy analysis, Fourier transform infrared spectroscopy, human lung carcinoma cell line, anticancer activity, human cervical cancer cell line, nutratherapeutic agent, lung cancer, Au     

Actinobacterial‐mediated synthesis of silver nanoparticles and their activity against pathogenic bacteria

In this study, silver nanoparticles (AgNPs) were biosynthesised by using acidophilic actinobacterial SH11 strain isolated from pine forest soil. Isolate SH11 was identified based on 16S rRNA gene sequence to Streptomyces kasugaensis M338‐M1^T and S. celluloflavus NRRL B‐2493^T (99.8% similarity, both). Biosynthesised AgNPs were analysed by UV–visible spectroscopy, which revealed specific peak at λ  = 420 nm. Transmission electron microscopy analyses showed polydispersed, spherical nanoparticles with a mean size of 13.2 nm, while Fourier transform infrared spectroscopy confirmed the presence of proteins as the capping agents over the surface of AgNPs. The zeta potential was found to be −16.6 mV, which indicated stability of AgNPs. The antibacterial activity of AgNPs from SH11 strain against gram‐positive (Staphylococcus aureus and Bacillus subtilis) and gram‐negative (Escherichia coli) bacteria was estimated using disc diffusion, minimum inhibitory concentration and live/dead analyses. The AgNPs showed the maximum antimicrobial activity against E. coli, followed by B. subtilis and S. aureus. Further, the synergistic effect of AgNPs in combination with commercial antibiotics (kanamycin, ampicillin, tetracycline) was also evaluated against bacterial isolates. The antimicrobial efficacy of antibiotics was found to be enhanced in the presence of AgNPs.Inspec keywords: antibacterial activity, silver, nanoparticles, electrokinetic effects, Fourier transform infrared spectra, microorganisms, nanofabricationOther keywords: actinobacterial mediated synthesis, silver nanoparticles, pathogenic bacteria, biosynthesis, acidophilic actinobacterial SH11 strain, pine forest soil, 16S rRNA gene sequence, Streptomyces kasugaensis M338‐M1T, S. celluloflavus NRRL B‐2493T, UV–visible spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, zeta potential, gram positive bacteria, Staphylococcus aureus, Bacillus subtilis, gram negative bacteria, Escherichia coli, disc diffusion, wavelength 420 nm, Ag     

Cytotoxicity of biologically synthesised bismuth nanoparticles against HT‐29 cell line

This study was purposed to examine the cytotoxicity and functions of biologically synthesised bismuth nanoparticles (Bi NPs) produced by Delftia sp. SFG on human colon adenocarcinoma cell line of HT‐29. The structural properties of Bi NPs were investigated using transmission electron microscopy, energy dispersive X‐ray, and X‐ray diffraction techniques. The cytotoxic effects of Bi NPs were analysed using flow cytometry cell apoptosis while western blot analyses were applied to analyse the cleaved caspase‐3 expression. Oxidative stress (OS) damage was determined using the measurement of the glutathione (GSH) and malondialdehyde (MDA) levels and antioxidant activity of superoxide dismutase (SOD) and catalase (CAT) levels. The half maximal inhibitory concentration (IC₅₀) value of Bi NPs was measured to be 28.7 ± 1.4 µg/ml on HT‐29 cell line. The viability of HT‐29 represented a concentration‐dependent pattern (5–80 µg/ml). The mode of Bi NPs induced apoptosis was found to be mainly related to late apoptosis or necrosis at IC₅₀ concentration, without the effect on caspase‐3 activities. Furthermore, Bi NPs reduced the GSH and increased the MDA levels and decreased the SOD and CAT activities. Taken together, biogenic Bi NPs induced cytotoxicity on HT‐29 cell line through the activation of late apoptosis independent of caspase pathway and may enhance the OS biomarkers.Inspec keywords: bismuth, nanoparticles, cellular biophysics, toxicology, nanomedicine, cancer, transmission electron microscopy, X‐ray chemical analysis, X‐ray diffraction, enzymes, biochemistryOther keywords: cytotoxicity, biologically synthesised bismuth nanoparticles, HT‐29 cell line, Delftia sp. SFG, human colon adenocarcinoma cell line, structural properties, transmission electron microscopy, energy dispersive X‐ray techniques, X‐ray diffraction, cytotoxic effects, flow cytometry cell apoptosis, western blot analyses, cleaved caspase‐3 expression, oxidative stress damage, glutathione, malondialdehyde, antioxidant activity, superoxide dismutase, catalase level, half maximal inhibitory concentration, cell viability, concentration‐dependent pattern, apoptosis, MDA levels, caspase pathway, Bi     

Antifungal effect of green synthesised silver nanoparticles against Setosphaeria turcica

Green synthesis of silver nanoparticles (AgNPs) is an interesting issue of the nanoscience and nanotechnology due to their unique properties. In the present study, Ginkgo biloba L. leaf extract was used to synthesise AgNPs. The effects of quantity of leaves, concentration of Ag nitrate (AgNO₃), reaction temperature, and pH were studied to discover the optimal synthesis system. In addition, antifungal effect of AgNPs against Setosphaeria turcica was measured through inhibition zone method. The optimal biosynthesis system contained 15 g of leaf, 8 mM AgNO₃, and 80°C at pH 9.0. Under mentioned conditions, the resulting synthesised NPs were nearly spherical, with an average size of 14 nm. In tests, AgNPs synthesised at different pH resulted in different inhibition zones, diameters increased gradually at pH from 3.0 to 11.0, while antifungal effect reached maximum at 9.0. Results of this study offer a new approach for biological control plant pathogenic fungi, and it has potential application for screening novel fungistats with high efficiency and low toxicity.Inspec keywords: antibacterial activity, silver, nanoparticles, nanobiotechnology, pHOther keywords: antifungal effect, green synthesised silver nanoparticles, Setosphaeria turcica, nanoscience, nanotechnology, Ginkgo biloba L. leaf extract, reaction temperature, pH, inhibition zone method, inhibition zones, mass 15 g, temperature 80 degC, size 14 nm, Ag     

Green synthesis of silver nanoparticles using Rubia tinctorum extract and evaluation the anti‐cancer properties in vitro

Cancer is one of the leading causes of human death. Nanotechnology could offer new and optimised anticancer agents in order to fight cancer. It was shown that metal nanoparticles, in particular silver nanoparticles (AgNPs) were effective in cancer therapy. In this study, AgNPs were synthesised using Rubia tinctorum L. extract (Ru‐AgNPs). Then, cytotoxicity effects of the Ru‐AgNPs against MDA‐MB‐231 carcinoma cell line and human dermal fibroblast as normal cell line were performed. Furthermore, anti‐apoptotic effects of Ru‐AgNPs on these cancer and normal cell lines were compared using acridine orange/propidium iodide staining, flow cytometry analysis and real‐time qPCR in apoptosis gene markers. Results of UV‐vis spectroscopy showed that Ru‐AgNPs have a peak at 430 nm, which indicated synthesis of AgNPs. Ru‐AgNPs had spherical shape and average size of 12 nm. Ru‐AgNPs have cytotoxicity on MDA‐MB‐231 cells and decrease cancerous cell viability (IC50 = 4 µg/ml/48 h). Ru‐AgNPs could induce apoptosis in MDA‐MB‐231 cells through upregulation of Bax and downregulation of Bcl‐2 gene expression. The results opened up new avenues to develop Rubia based metal complexes as an anticancer agent.Inspec keywords: cellular biophysics, genetics, cancer, toxicology, nanoparticles, nanofabrication, nanomedicine, silver, biomedical materials, ultraviolet spectra, visible spectraOther keywords: Ru‐AgNPs, MDA‐MB‐231 carcinoma cell line, normal cell line, cancerous cell viability, in vitro anticancer properties, green synthesis, silver nanoparticles, Rubia tinctorum L. extract, cytotoxicity effects, human dermal fibroblast HFF, antiapoptotic effects, acridine orange‐propidium iodide staining, flow cytometry analysis, real‐time qPCR, apoptosis gene markers, UV‐visible spectroscopy, spherical shape, Bcl‐2 gene expression, Ag     

In vitro biological evaluation of anti‐diabetic activity of organic–inorganic hybrid gold nanoparticles

Diabetes mellitus has been considered as a heterogeneous metabolic disorder characterised by complete or relative impairment in the production of insulin by pancreatic β‐cells or insulin resistance. In the present study, propanoic acid, an active biocomponent isolated from Cassia auriculata is employed for the synthesis of propanoic acid functionalised gold nanoparticles (Pa@AuNPs) and its anti‐diabetic activity has been demonstrated in vitro. In vitro cytotoxicity of synthesised Pa@AuNPs was performed in L6 myotubes. The mode of action of Pa@AuNPs exhibiting anti‐diabetic potential was validated by glucose uptake assay in the presence of Genistein (insulin receptor tyrosine kinase inhibitor) and Wortmannin (Phosphatidyl inositide kinase inhibitor). Pa@AuNPs exhibited significant glucose uptake in L6 myotubes with maximum uptake at 50 ng/ml. Assays were performed to study the potential of Pa@AuNPs in the inhibition of protein‐tyrosine phosphatase 1B, α‐glucosidases, and α‐amylase activity.Inspec keywords: molecular biophysics, biomedical materials, sugar, enzymes, nanofabrication, gold, patient treatment, organic‐inorganic hybrid materials, biochemistry, diseases, cellular biophysics, nanoparticles, toxicology, nanomedicineOther keywords: glucose uptake assay, α‐amylase activity, organic–inorganic hybrid gold nanoparticles, diabetes mellitus, heterogeneous metabolic disorder, pancreatic β‐cells, insulin resistance, propanoic acid, antidiabetic potential, antidiabetic activity, in vitro cytotoxicity, L6 myotubes, Genistein, IRTK inhibitor, Wortmannin, P13K inhibitor, protein‐tyrosine phosphatase 1B, α‐glucosidases, Cassia auriculata, Au     

Biomimetic synthesis and anticancer activity of Eurycoma longifolia branch extract‐mediated silver nanoparticles

In the present study, silver nanoparticles (AgNPs) were synthesised by adding 1 mM Ag nitrate solution to different concentrations (1%, 2.5%, 5%) of branch extracts of Eurycoma longifolia, a well known medicinal plant in South–East Asian countries. Characterisation of AgNPs was carried out using techniques such as ultraviolet–visible spectrophotometry, X‐ray diffractrometry, Fourier transform infrared–attenuated total reflection spectroscopy (FTIR–ATR), scanning electron microscopy. XRD analysis revealed face centre cubic structure of AgNPs and FTIR–ATR showed that primary and secondary amide groups in combination with the protein molecules present in the branch extract were responsible for the reduction and stabilisation of AgNPs. Furthermore, antioxidant [2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐Azino‐bis(3‐ethylbenzthiazoline‐6‐sulphonic acid)], antimicrobial and anticancer activities of AgNPs were investigated. The highest bactericidal activity of these biogenic AgNPs was found against Escherichia coli with zone inhibition of 11 mm. AgNPs exhibited significant anticancer activity against human glioma cells (DBTRG and U87) and human breast adenocarcinoma cells (MCF‐7 and MDA‐MB‐231) with IC₅₀ values of 33, 42, 60 and 38 µg/ml.Inspec keywords: biomimetics, cancer, antibacterial activity, nanoparticles, silver, microorganisms, cellular biophysics, biomedical materials, nanomedicine, nanofabrication, X‐ray diffraction, Fourier transform infrared spectra, attenuated total reflection, ultraviolet spectra, visible spectra, proteins, molecular biophysics, biochemistryOther keywords: Biomimetic synthesis, anticancer activity, Eurycoma longifolia branch extract‐mediated silver nanoparticles, nitrate solution, medicinal plant, ultraviolet‐visible spectrophotometry, X‐ray diffractometry, Fourier transform infrared‐attenuated total reflection spectroscopy, FTIR‐ATR spectroscopy, scanning electron microscopy, XRD, face centre cubic structure, primary amide groups, secondary amide groups, protein molecules, antioxidant, 2,2‐diphenyl‐1‐picrylhydrazyl, 2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulphonic acid), antimicrobial activity, bactericidal activity, biogenic silver nanoparticles, Escherichia coli, zone inhibition, DBTRG human glioma cells, U87 human glioma cells, MCF‐7 human breast adenocarcinoma cells, MDA‐MB‐231 human breast adenocarcinoma cells, Ag