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In this study, we harnessed the properties of desert plants to synthesize silver nanoparticles to explore potential antimicrobial solutions. Chrozophora plicata and Heliotropium curassavicum extracts were used as green reducing agents to transform silver ions into nanoparticles. Our findings revealed novel properties of C. plicata, which have not been reported before. Surface plasmon resonance peak at 453.6 and 431 nm for C. plicata and H. curassavicum, respectively, via ultraviolet (UV) spectral analysis evidenced the successful fabrication of silver nanoparticles with particle sizes ranging from 4.3-8 and 3.1-6.97 nm respectively, which was validated by field emission scanning electron microscopy (FE-SEM). X-ray diffraction analysis revealed that the crystal structure of these nanoparticles had a face-centered cubic geometry. Fourier transform infrared spectrometry of the plant extract showed strong signals corresponding to carbohydrates, proteins, and phenolics. Antibacterial assays of the silver nanoparticles from C. plicata displayed zones of inhibition at 5 and 4 mm against Staphylococcus aureus and Escherichia coli, respectively. Meanwhile, the silver nanoparticles from H. curassavicum exhibited zones of inhibition against both pathogens at 10 and 7 mm, respectively. The test samples were substantial inhibitors of S. aureus and E. coli biofilm formation since these displayed IC50 values in the range of 8.88-10.57 mg/mL, which is as potent as the reference ciprofloxacin. Consequently, the silver nanoparticles derived from these desert plants can be potential drug candidates for treating respiratory and digestive tract infections alone or in combination with existing antibiotics. [ABSTRACT FROM AUTHOR]

Antibacterial resistance among uro-pathogens has become a global issue for bacterial infection treatment. The antibacterial activity of various plant extracts and silver nanoparticles (AgNPs) derived from medicinal plant extract was evaluated against different drug-resistant uro-pathogens isolated from clinical patients by Agar Well Diffusion and Minimum Inhibitory Concentration (MIC) assays. A total of 100 urine samples were collected from patients admitted to the hospital followed by the identification of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Enterobacter aerogenes, and Klebsiella pneumonia through colony morphology, gram staining, and biochemical characterization. All isolates were highly resistant to all the tested drugs except Amikacin, Gentamicin, and Imipenem. Organic extracts of clove have potent antibacterial activity against all drug-resistant isolates. Interestingly P. aeruginosa was sensitive to all inorganic extracts. These results revealed that the organic extracts of medicinal plants showed more consistent antimicrobial activity compared to their aqueous fraction. Furthermore, the green synthesis of AgNPs derived from clove extract showed strong activity against all tested pathogens followed by green synthesis of AgNPs derived from garlic, ginger, kalwonji, turmeric, and thymus extract respectively compared to medicinal plant extract. Moreover, MIC results showed that AgNPs derived from medicinal plant extract indicate higher efficiency in inhibiting bacterial growth than the medicinal plant extract. The current finding shows that AgNPs derived from plant extract can be recommended as a good alternative for treating the resistant uro-pathogens strains as compared to synthetic drugs and will be considered an attractive candidate for future biological applications. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the efficacy of silver nanoparticles (AgNPs) synthesized by cold plasma in inhibiting biofilm formed by Staphylococcus epidermidis both phenotypically and genotypically. The resultant AgNPs were characterized by using different parameters, color change, Xray diffraction (XRD), zeta potential, feld emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM) methods. Moreover, their efficacy in inhibiting S. epidermidis biofilm was studied by the microtiter plate method. The results revealed that cold plasma succeeded in the synthesis of AgNPs with a size range of 10-20 nm. Markedly, the present findings indicated a significant decrease (P < 005) in the intensity of all tested biofilm alongside the down-regulation of accumulation-associated protein (aap) and AtlE in the presence of AgNPs as compared with non-treated cells. In conclusion, AgNPs synthesized by cold plasma acted as antibiofilm agents and could be used for pharmaceutical applications. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (AgNPs) were synthesized in an environmentally friendly manner using plant extracts from Luisia tristis. The formation of the nanoparticles was confirmed by a reddishbrown colour change and further characterized using ultraviolet-visible (UV-Vis), Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), and transmission electron microscope (TEM) techniques. The average size of the particles was found to be 16-48 nm. The antimicrobial activity of the AgNPs was evaluated against harmful bacteria and compared to the commonly used antibiotic ciprofloxacin. The AgNPs were found to be highly effective, with a 24 mm zone of inhibition against Escherichia coli, and more effective than ciprofloxacin. Additionally, a minimum inhibitory concentration assay was performed with a concentration of 100 mg/mL of AgNPs, which were found to effectively inhibit the growth of selected pathogens. Overall, the study demonstrates the potential for using plant-derived AgNPs as a natural and eco-friendly alternative for antimicrobial and antioxidant applications. This method is a fast, cost-effective way to generate silver nanoparticles at room temperature and may be useful in creating environmentally friendly antibacterial solutions for biomedical applications. [ABSTRACT FROM AUTHOR]

The possible treatment of cancer with nanoparticles (NPs) would be carried out via inoculation into the veins; as a result, the NPs would come into contact with white blood cells (WBCs) and red blood cells (RBCs) prior to reaching the target cancerous cells. In the current study, the genotoxicity and cytotoxicity potential of silver NPs (AgNPs) against human blood lymphocytes and baby hamster kidney-21 (BHK-21) cells was tested using comet and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assays, respectively. First, AgNPs were created using a Heliotropium eichwaldi L. (HE) extract. These AgNPs were then confirmed by ultraviolet-visible (UV-Vis) spectroscopy, which yielded a sharp peak at 416 nm with a maximum absorbance of 1.92. Moreover, an X-ray diffraction (XRD) analysis confirmed the crystalline nature and particle size (19.79 nm) of AgNPs, whereas scanning electron microscopy (SEM) revealed their irregular morphology and size of 30 nm. In turn, an EDX analysis indicated that AgNPs had an appreciable composition of Ag ions (30.68%). According to the comet assay, the HE-AgNPs, and standard H2O2 caused highly significant damage to DNA compared with HE extract. The comet assay was reported in terms of the total comet score (TCS). In the case of the MTT assay, a dose-dependent cytotoxicity was noted, in which doxorubicin, and AgNPs were more potent against BHK-21 cells compared with a plant extract. From these results, it is evident that the green-synthesized AgNPs interacted with blood lymphocytes and BHK-21 cells, caused damage to DNA via oxidative stress, and finally triggered cell death (apoptosis). However, further studies aimed at reducing their potential threats are recommended. [ABSTRACT FROM AUTHOR]

Fresh pomegranate peel extract was employed to synthesize silver oxide nanoparticles (Ag2O NPs). Rapid formation of stable Ag2O NPs was observed on exposure to the aqueous fresh pomegranate peel extract with solution of AgNO3. The Ag2O NPs were characterized by X-ray analysis, scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis) spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The X-ray diffraction (XRD) confirmed that the forming Ag2O NP has a crystalline size of 37 nm, while SEM micrographs revealed a comparatively spherical shape, with the size of ~ 64 nm. The Ag2O spectrum displayed a peak in the visible range and a blue shift at 461 nm corresponding to the Plasmon absorbance of silver nanoparticles. Four bacterial strains and one type of fungus were tested using Ag2O NPs. The results showed the negative influence of Ag2O NPs on the growth rate, thus implying the significance of the present study in production of biomedical products. [ABSTRACT FROM AUTHOR]

Excessive utilization of nanoparticles renders it necessary to produce safer and more secure nanoparticles while preserving their efficacy. In this study, Psidium guajava L. pulp extract-mediated silver nanoparticles (AgNPs) were synthesized, characterized, and further evaluated regarding their antioxidant potential. The green synthesized silver nanoparticles (G-AgNPs) showed a higher level of radical scavenging activity (RSA) (25.85%), hydrogen peroxide scavenging activity (34.34%), and ferric reducing power (0.28). The comparison of the control group (G1) with the various treatment groups (G2-G6) revealed that the levels of catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST) were significantly different (P < 0.05). The levels of blood urea, uric acid, blood urea nitrogen (BUN), serum glutamic pyruvic transaminase (SGTP), serum creatinine, serum glutamic-oxaloacetic transaminase (SGOT), alkaline phosphatase, total bilirubin, and serum electrolytes were also evaluated. The results of clinical biochemistry also strengthened our hypothesis that G-AgNPs are less toxic than C-AgNPs. Finally, the histopathology of liver, kidney, and intestinal tissues indicated that green-synthesized AgNPs are relatively safer. [ABSTRACT FROM AUTHOR]

In recent years, there has been increased interest in the use of nanostructures in various industries, such as the food, textile, pharmaceutical, electronics, and chemical industries. Most of these applications require a proper preparation of specific nanomaterials. In this study, we characterized silver nanoparticles (AgNPs) stabilized with polyvinylpyrrolidone and prepared in aqueous suspensions using dynamic light scattering, atomic force microscopy, and transmission electron microscopy. We aimed to compare the influence of different AgNP preparation procedures, specifically autoclaving, sonication, and a combination of both, on the agglomeration of these nanoparticles. Additionally, the toxicity of the NPs after the selected sterilization methods toward the EA.hy926 endothelial cell line was determined using trypan blue labeling, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) tetrazolium salt reduction tests, and the 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium bromide (MTT) tetrazolium bromide test. Based on the obtained results, we concluded that cells exposed to AgNPs after sonication had similar viability values above 80% across all cellular viability tests. Conversely, the cellular viability values of the EA.hy926 cell line exposed to the autoclaved AgNP solutions differed. From the XTT tests, we observed a falsely determined cellular viability value above 100% with a simultaneous increase in the XTT-measured absorbance for the cellular medium after autoclaving. However, the other viability tests showed a cellular viability value below 25%. The results prove the importance of selecting an appropriate method for measuring cell viability, especially for cells exposed to previously sterilized nanomaterials. [ABSTRACT FROM AUTHOR]

In this study, the synthesis of nanoparticles and their biological evaluation were carried out. A green synthetic approach synthesized silver nanoparticles (AHAgNPs) using an Artocarpus heterophyllus leaf extract. Parameter optimization was performed using Design Expert Ver. 13. The effects of variables like the concentration on the response, particle size, and entrapment efficiency of synthesized AHAgNPs were monitored via analysis of variance. The optimized AgNPs were characterized using ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy. Scanning electron microscopy and transmission electron microscopy were used to determine the size and shape of nanoparticles. In vitro, antioxidant and antimicrobial potential were determined using standard protocols. The optimized nanoparticles were spherical, with an average 100-110 nm particle diameter. The synthesized nanoparticles showed effective antioxidant, antibacterial, and antifungal activity. In addition, AHAgNPs showed increased biological activities. [ABSTRACT FROM AUTHOR]

The present study is based on optimized green synthesis of silver nanoparticles (AgNPs) using Manilkara zapota fruit extract, formulation of topical gels, and evaluation for their antimicrobial properties. The results reveal that a reaction temperature of 35 °C and a reaction time of 11 h are the optimum conditions to get spherical AgNPs with a particle size of 100.7 nm and a zeta potential of -26.7 mV. The synthesized AgNPs formulated as topical gels demonstrate a broad-spectrum antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Aspergillus niger in comparison to the 0.2% (mass fraction) silver nitrate marketed formulation. The AgNPs loaded gels seem promising and could lead to a useful alternative for treating pathogenic infections. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles (AgNPs) is attaining more attention from researchers over chemical fabrication due to their unique properties such as high dispersion in solution, surface-tovolume ratio, low toxicity, and easy preparation. In this paper, a biogenic synthesis of Kickxia elatinebased-silver nanoparticles (KE-AgNPs) was carried out by using K. elatine plant extract (KEE). The characterization of synthesized AgNPs was done by ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and Fourier transform infrared (FTIR) analyses. XRD screening confirmed the crystalline nature of KE-AgNPs with 42.47 nm in size. SEM analysis confirmed the rounded shape AgNPs with 50 nm in size. FTIR confirmed the various functional groups that contribute to the stabilization and reduction of AgNPs. EDX displayed an intense peak (3.2 keV), presenting that Ag has a chief component with 61.67%. These AgNPs showed a potential antioxidant activity against 2,2'-azino-bis-(3-ethyl) benzothiazoline-6-sulfonic acid (ABTS, 66.9%), diphenyl-1-picrylhydrazyl (DPPH, 72.49%), H2O2 (69.42%), ferricreducing antioxidant power assay (FRAP, 70.04%), and ammonium molybdenum (68.77%) at the highest concentration of 160 µg/mL. Statistical analysis showed that both KEE and their AgNPs inhibit alpha-amylase (α-amylase) in the mixed type mode, i.e., Michaelis constant (Km) increased (16.62%-55.45% and 49.77%-134.78% for KE-AgNPs) and Vmax decreased (2.68%-12.98% and 4.44%-11%), respectively. In the case of anti-acetylcholinesterase studies, both KEE and AgNPs revealed a mixed-type inhibition against acetylcholinesterase (AchE), i.e., Km increased (13.53%-101.48% and 10.10%-38.04%), while Vmax decreased (12.66%-52.47% and 11.91%-41.69%) for KEE and KE-AgNPs, respectively. Therefore, the synthesized AgNPs could be used for various purposes due to their non-toxicity, eco-friendly, and compact ability for therapeutic and diagnostic applications. [ABSTRACT FROM AUTHOR]

Agaricus biosporus is a mushroom known for its use for nutritional and medicinal purposes. This study tested whether silver nanoparticles (AgNPs) synthesized from phenolic compounds extracted from this mushroom have an efficient antimicrobial impact against pathogenic bacteria and yeast isolated from urine, sputum, and vaginal swabs. Different methods were employed in the characterization of AgNPs. The microorganisms of isolated bacteria and yeast were identified according to morphological features, results of biochemical tests, and the VITEK 2 compact system. The susceptibility to antibiotics was determined by the disk method. The bacteria and yeast resisted all antibiotics employed in this research. But the AgNPs had good antimicrobial activity against pathogenic bacteria and yeast. The highest inhibition zone of AgNPs against Pseudomonas aeruginosa in a 100 mg/mL concentration was 30 mm, while the minimal inhibition zone of AgNPs was 12 mm against Escherichia coli at the same concentration. The antibacterial effect of the synthesized AgNPs was concentration-dependent against Gram-positive and Gram-negative bacteria. With respect to the effect on yeast growth, there was a clear inhibitory effect of the synthesized AgNPs at 100 mg/mL, when the largest zone of inhibition was found against Candida glabrata (29 mm), and the minimal inhibition zone was found against C. guillermondi and C. albican (23 mm). Similarly, the AgNPs synergized with antibiotics were used against pathogenic bacterial and yeast isolates because when antibiotics and AgNPs were combined, the inhibition zones were larger compared to those of the antibiotics alone. [ABSTRACT FROM AUTHOR]

This study was conducted to identify promising applications of green silver nanoparticles (AgNPs) prepared from a bark extract of Sweetinia mahagoni (Sm). The green synthesized Sm-AgNPs were characterized using various spectroscopy methods. AgNPs were first investigated using ultraviolet-visible spectroscopy, and the metal nanoparticles exhibited an intense surfaceplasmon resonance (SPR) peak at different wavelengths. The green synthesized Sm-AgNPs had an SPR peak at 430 nm, which confirms the formation of Sm-AgNPs. In addition, Fourier transform infrared (FTIR) spectroscopy was conducted to determine the bioactive compounds of bark extract that actively participate in the reduction of Sm-AgNPs, and the results revealed O-H stretching of free hydroxyl alcohol and phenols, N-H bonds of primary amines, S=O stretching of sulfoxide in aromatic groups, C-I stretching due to aliphatic iodo compounds, and C-Br stretching by halo compounds of the bark extract which might reduce and stabilize Sm-AgNPs. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) results revealed that Sm-AgNPs were approximately irregular spheres. EDS results revealed the complete reduction of silver to elemental silver. The particle size analysis of Sm-AgNPs was conducted using dynamic light scattering (DLS), and the results revealed that Sm-AgNPs were polydisperse with an average size range from 35.8 to 47.8 nm, an average mean size of 41.3 nm, and a Z average of 37.7 nm. Sm-AgNPs had a negative zeta potential value of -19.0 mV, indicating that Sm-AgNPs were very stable in colloidal form. Further studies were carried out to demonstrate their usefulness in industrial and biomedical applications. In these studies, Sm-AgNPs exhibited a very good antibacterial activity against both Gram-negative and Gram-positive bacteria. In addition to regular assays, we also investigated important industrial applications such as the reduction of toxic hexavalent chromium to a nontoxic form and sensing of Hg2+ ions. The results revealed that Sm-AgNPs had an excellent performance in biosensor applications such as sensing and detecting mercury at parts per million/parts per billion levels. In conclusion, green Sm-AgNPs are promising materials in therapeutic and industrial applications. [ABSTRACT FROM AUTHOR]

This study investigates an efficient and sustainable route of preparing Ag nanoparticles (NPs) using 1-5 mmol/L aqueous silver nitrate with leaf extracts of five plants--Musa balbisiana (banana), Azadiracta indica (neem), Ricinus communis (castor-oil plant), Tridax procumbens (tridax), and Cardiospermum halicacabum (balloon vine) for their wide availability. These synthesized nanoparticles were characterized with the help of ultraviolet (UV)-visible (Vis) spectrophotometer. The peaks were observed in 418-493 nm. For M. balbisiana, A. indica, R. communis, and C. halicacabum, the average size of nanoparticles was in the range of 90-100 nm. For T. procumbens, it was 39-60 nm as determined by dynamic light scattering. Energy dispersive X-ray spectroscopy analysis showed the peak in silver region confirming presence of elemental silver. Field emission scanning electron microscopy showed that the particles were of a spherical shape in M. balbisiana sample with an average size of 33.87 nm as well as in T. procumbents sample with an average size of 28.512 nm. Ag NPs showed effective antibacterial and antifungal activity against representative pathogens of bacteria and fungi. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity of Ag NPs was found to be in the range of 8.9%-78.86%. H2O2 radical scavenging activity was recorded in the range of 6.036%-57.342%. The nanogel was prepared from synthesized Ag NPs, and its properties like viscosity and stability were evaluated. The results confirmed that this protocol is a simple, rapid, one-step, eco-friendly, nontoxic, and alternative conventional physical/chemical method. [ABSTRACT FROM AUTHOR]

Recent investigations on green synthesis of silver nanoparticles (AgNPs) have been widely used in various therapeutic and industrial applications. So in the present study, AgNPs and PVP coated AgNPs were biosynthesized using fig fruit (Ficus carica) named as FF-AgNPs PVP-FF-AgNPs. The FF-AgNPs and PVP-FF-AgNPs revealed the surface Plasmon resonance band at 446 nm and 460 nm respectively. The FT-IR analysis of both nanoparticles reveals that different bioactive components of the fruit extract were actively involved in reduction of AgNPs. The SEM revealed that the particles are roughly spherical and irregular in shape and size, EDX analysis confirms the formation of complete reduction of silver to elemental silver. DLS studies also revealed similar results with both the nanoparticles are within the range of 10 ± 5 nm to 35 ± 5 nm. The zeta potential studies reveal negative potential values were as follows FF-AgNPs has -13.8 mV and PVP-FF-AgNPs has -17.1 mV. They also exhibit good antimicrobial activity. Another important application of these nanoparticles is dual detection of toxic chromium (VI) and photocatalytic dye degradation of cotton blue by H2O2 quenching and without quenching. It is concluded that, biosynthesized FF-AgNPs and PVP-FFAgNPs have multiple applications of economic importance and environmental pollution. [ABSTRACT FROM AUTHOR]

In the current research, silver nanoparticles (AgNPs) were mixed with a polymer blend to enhance their optical and electrical properties and antibacterial efficiency. A novel approach via introducing AgNPs into the polymer blend could improve the physical and antibacterial characteristics of the nanocomposites (NCs). In the loading process, two different amounts of AgNPs were respectively encapsulated with polyvinyl alcohol (PVA), polyacrylamide (PAAm) and polyethylene oxide (PEO) polymeric blend via casting method. The prepared films were characterized by X-ray, optical microscope (OM), scanning electron microscopy (SEM), Fourier transformation infrared (FTIR) and UV/Visible. The OM and SEM images showed that the AgNPs were well diffused inside the polymer blend with some weak aggregations. The optical properties were enhanced after doping. The NCs films absorbed UV-ray at (λ=220 nm). The indirect energy gap decreased after loading from 3.80 to 3.10 eV but the direct energy gap decreased from 4.25 to 3.75 eV. The AC electrical properties were studied in the frequency range between 100 Hz to 5 MHz. The dielectric constant and loss of NC films were decreased with the increase of AgNPs, while the electrical conductivity increased. The inhibition zone diameters of Escherichia coli bacteria increased with the increasing of AgNPs contents. [ABSTRACT FROM AUTHOR]

The effective delivery of drugs to the targeted tissues or cells has always been a cause of concern. Nanotechnology has emerged as an effective tool to solve this problem of targeted drug delivery. The development of nanoparticle drug delivery systems is a revolutionary step in the healthcare domain. Nanoparticles loaded with drugs, known as nanomedicines, are used to achieve site-specific delivery of drugs that reduces the amount of required dose and, hence, toxicity. The nanoparticles, due to their small sizes, can easily cross the cell barriers. Also, the surface of the nanoparticles can be modified in such a way that it can be recognized by the molecules on the targeted cells. The addition of ligands, antibodies, aptamers, etc., is done to modify the surface. Therefore, these nanoparticle drug delivery systems are used to obtain targeted delivery of drugs, controlled delivery, biocompatibility, low toxicity and degradation within acceptable time period. The novel drug delivery techniques involving nanoparticles are designed to improve the pharmacological and therapeutic properties of drugs. Nowadays, metallic as well as biodegradable nanoparticles are used as effective drug carriers for cancer, cardiovascular diseases, brain related disorders and so on. Metallic nanoparticles are obtained by the reduction of metallic ions from their solutions to the nano-size range. Of the metallic nanoparticles, Gold is studied very extensively due to its inert nature and relatively high biocompatibility than other metals. Biodegradable nanoparticles are synthesized from polymeric substances such as polylactic acid (PLA), gelatin, chitosan, etc. Some other examples of nanoparticles are dendrimers, liposomes, carbon-based, viral based, etc. [ABSTRACT FROM AUTHOR]

In recent years, silver nanoparticles (Ag NPs) had produced by biological methods such as plant extract due to their efficiency, low cost, being non-toxic, and ecofriendly nature. Ag NPs have antibacterial, anti-mold, and anti-fungi because of their high surface area to volume ratio. In this study, Opuntia ficus-indica (Prickly pear) extract was used to produce green synthesized Ag NPs. Different techniques had adopted to describe the generated nanoparticles, such as an ultraviolet spectrophotometer, Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), and Zeta Potential Analysis. Escherichia coli (E. coli), separated from sediment and water of the Hillah River in Babylon city in Iraq, was utilizedto estimate the antibacterial activities of Ag NPs at different concentrations. Both broth microdilution assay and well diffusion assay were applied. The Congo Red Agar implied to investigate the ability of E. coli isolates to form a biofilm. The TEM images of Ag NPs illustrated spherical morphology with a diameter of approximately 22±4 nm. The antibacterial activity tests showed that the Minimum Inhibitory Concentration (MIC) ranged from 0.0125 mg·L-1 to 0.05 mg·L-1, whereas Minimum Bactericidal Concentration (MBC) was from 0.025 mg·L-1 to 0.05 mg·L-1. 5 h of exposure to the 0.025 mg·L-1 concentrations of the Ag NPs had a bactericidal impact on 92% of the E. coli isolates. In our study, we found silver nanoparticles synthesized by Opuntia ficus-Indica have antibacterial activity against waterborne Escherichia coli isolates and it could be utilizedtoreduce microbial growth in contaminated water. [ABSTRACT FROM AUTHOR]

Sensitive and simple colorimetric method was developed for determination of methyldopa and terbutaline sulphate in pure and pharmaceutical dosage forms. The method was based on reduction of silver ions by the cited drugs in basic medium at 90 °C to silver nanoparticles in the presence of stabilizing agent as polyvinylpyrrolidone. The formed silver nanoparticles were distinguished by UV-Vis absorption spectroscopy indicating the characteristic surface plasmon resonance which can be also observed as intense yellow color solution. The plasmon absorbance of the silver nanoparticles was measured at 410 nm for quantitative estimation of methyldopa and terbutaline sulphate over the range of 80-480 and 40-600 ng/mL respectively. Limit of detection was obtained as 26, 13 ng/mL for methyldopa and terbutaline sulphate respectively. The eco-friendly developed method could be successfully applied to the pharmaceutical formulations with studying the interference of different excipients. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are of potential interest because of their effective antibacterial and antiviral activities. Capping agents are used for exhibiting a better antibacterial activity than uncapped Ag NPs. There are very few reports that have shown the usage of AgNPs for in-vivo antibacterial therapy. Citrate-capped silver nanoparticles were synthesized chemically by citrate reduction method; the size of Cit-AgNPs was determined by an atomic force microscope (AFM) and was between 15 - 90 nm. Acinetobacter baumannii (A. baumannii) isolates were the only sensitive species to Cit- AgNPs. MICs and MBC of Cit-AgNPs were determined by using A. baumannii. The results showed an additive effect of Cit-AgNPs. Four mice groups were infected with a sub-lethal dose of A. baumannii intraperitoneally, IP. The single daily dose of Cit-AgNPs and imipenem plus Cit-AgNPs combination were administered IP. Imipenem and phosphate buffer saline (PBS) was used as positive control and negative control, respectively. Interestingly, only the PBS-treated group showed growth of A. baumannii in the liver and spleen of sacrificed mice. Histopathologically, Cit-AgNPs showed antibacterial activity and had an additive effect when combined with imipenem in vivo and in vitro. Moreover, the Cit-AgNPs showed dose-dependent activity and the organs differed in the illumination of the toxicity effect of Cit-AgNPs even after high dose administration. In conclusion, Cit-capped AgNPs had antibacterial activity against multiple drug resistant (MDR) A. baumannii but not against K. pneumoniae and E. coli. Cit-capped AgNPs increased the inhibition zone of imipenem in additive effect; the minimum inhibitory concentration and the minimum bactericidal concentration of Citcapped AgNPs were relatively low. Cit-capped AgNPs eliminated A. baumannii infection in vivo when it was given alone or in combination with imipenem. The cytotoxicity of Cit-AgNPs was dosedependent and the organs differed in the illumination of the inflammatory effect of Cit-AgNPs after high dose administration. It is not recommended to use Cit-capped AgNPs systemically despite their valuable additive antibacterial effect especially with a high dose and the combination with imipenem, Topical administration needs to be evaluated. [ABSTRACT FROM AUTHOR]

The wide use of metal nanoparticles has raised the concern of their release in the environment and their biological safety. The use of silver nanoparticles (Ag NPs) as effective antimicrobial agent is also questioned due to the resistance developed by pathogens and the biosafety for the host. The genotoxicity caused by such particles need to be assessed to ensure that they are safe to use. In this study, green synthesized Ag NPs were used and the biosafety in terms of genotoxicity was evaluated by in vitro Chromosome aberration (CA) assay using short-term cultures of human peripheral blood. The physicochemical parameters of these Ag NPs were studied for stability in nano form. The transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS) were carried out. The dynamic light scattering and zeta potential measurements revealed stable nano particles. The UV visible & fluorescence spectroscopy for binding affinity of Ag NPs did not suggest significant DNA interaction. The exposure of whole blood cultures to Ag NPs for 24 h showed dose dependent increase in frequency of CA per cell at 350, 650 and 1000 µL (P = NS, P < 0.05 and P < 0.001 respectively). Our study demonstrates that genotoxicity of Ag NPs can be reduced by the use of green synthesized Ag NPs at low dose exposure, which will guide selecting right concentrations of NP for further in vivo studies, and future applications. [ABSTRACT FROM AUTHOR]

Sliver nanoparticles (Ag NPs) are produced industrially and commercially available in recent time. Silver and its nanoparticles are widely applied to consuming medical purposes. Silver nanoparticles are able to resemble cellular components and typical proteins, which helps the nanoparticles to cross natural barriers in human body. For this reason, the current study was designed to investigate the damage caused by silver nanoparticles, especially in liver which is one of the most targeted organs of nanoparticles as a result of their accumulation and damages caused in various aspects such as tissue, functional ability and DNA of liver cells. 30 albino male rats were used for this study and were divided into 3 main groups. The first group represented control and a normal saline solution was given, while the second group was given silver nanoparticles at a concentration of 2 mg/kg of body weight, and the third group was given silver nanoparticles at a concentration of 3 mg/kg of body weight. Each concentration of Ag NPs was dissolved in 3 mL of the normal saline and given directly to the experimental animal's stomach by feeding tube with diameter of 0.6 cm and every day for 10 weeks. The results in the current study showed histopathological change in liver tissue such as large granulomatous lesion with an increase in macrophage numbers, as also shown by necrotic hepatocytes with dilation of sinusoids. The deformation of architecture in the parenchyma appeared in both concentrations. The biochemical parameters investigation in the liver clarified increased level of enzymes accordance with doses of Ag NPs. The damage was identified in DNA of hepatocytes by comet assay and the degree of damage was evident through increasing the numbers of tailed nuclei and in strand breaks of DNA. The reactive oxygen species (ROS) generation had a key role in the events of structural and functional disorders in the liver of experimental animals. [ABSTRACT FROM AUTHOR]

Eco-friendly synthesis of nanoparticles is an upcoming discipline of nanoscience. Green synthesis of Ag NPs has gained immense importance and much awareness in developed nations. Fascinatingly, such an environmental friendly synthesis of Ag NPs gives a green chemistry-based non-toxic and economical route to nanotechnology. This review article gives insight into the bioinspired synthesis of Ag NPs and mechanisms involved in the synthesis of Ag NPs. In this review, we have summarized the scientific reports in the eco-friendly synthesis arena of Ag NPs and their applications in the biomedical field. Especially, we have focused on plant materials, fungi, algae, and bacterial potential towards the eco-friendly synthesis of Ag NPs. For future perception, there is a need for in silico and in vitro, in vivo research to authenticate the outcomes. [ABSTRACT FROM AUTHOR]

The biosynthesis of metal nanoparticles is an emerging area of advanced research in plant protection. In this study, an eco-friendly and rapid protocol was developed where silver nanoparticles were biosynthesized by using Streptomyces spp. The biocontrol agent was isolated from different tea soils and the efficient strain (VASC201) was identified by dual culture and antibiosis. Nanoparticles were successfully synthesized from this efficient strain. The silver nanoparticles exhibited their resonance peak at 448 nm under ultraviolet-visible spectroscopy (UV-Vis). The structural analysis of the silver nanoparticles synthesized by the Streptomyces spp. exhibited a strong crystalline structure. The morphology and chemical composition of the silver nanoparticle were examined by high-resolution transmission electron microscopy (HR-TEM) equipped with energy-dispersive X-ray spectrometer (EDX) and were predominantly spherical in shape and uniformly distributed without significant agglomeration. The average crystalline size of the prepared silver nanoparticle was found to be 51.2 nm. The stretching vibrational peak at 3420, 2920 and 2350 cm-1 in Fourier-transform infrared spectroscopy (FTIR) were attributed to various functional group of metal nanoparticle synthesis. We assessed the effectiveness of silver nanoparticles against Poria hypolateritia and Phomopsis theae. The results showed that the nanoparticles showed very good inhibitory effect of about 69.90% inhibition of Poria at 5 ppm concentration on the 15th day. Phomopsis was inhibited to 67.47% at 5 ppm of silver nanoparticles at the same time interval. [ABSTRACT FROM AUTHOR]

In the present investigation, biogenic silver nanoparticles were synthesized using aqueous extract of Mexican poppy plant Argemone mexicana (AM-Ag NPs); their involvement in striking cytotoxicity and genotoxicity potential was explored. The biosynthesis of nanoparticles was confirmed by ultraviolet-visible spectroscopy (UV-Vis) and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform-infrared spectrometry (FTIR) and X-ray diffraction (XRD). The mechanism of inhibition of cell proliferation by Ag NPs was illustrated using human cervical adenocarcinoma (HeLa), human breast adenocarcinoma (MCF-7) and human colon adenocarcinoma (HCT-15) cells. In selected cancer cells, molecular mechanism involved in induction of apoptosis in response to biogenic Ag NPs was demonstrated by DNA fragmentation assay, and alteration in expression of apoptotic genes including caspase-3 and p53 was analyzed by RT-PCR and western blotting. The overall results construed that biosynthesized AM-Ag NPs exhibited cytotoxicity effect against tested HeLa, MCF-7 and HCT-15 cell lines in a dose dependent manner where 20 µg/mL concentration of AM-Ag NPs killed more than 95% of HeLa and MCF-7 cells after 24 h exposure, whereas HCT-15 cells required 50 µg/mL AM-Ag NPs to inhibit 95% cell growth. AM-Ag NPs significantly induced cellular DNA damage in HeLa and MCF-7 cells when treated up to 20 µg/mL and HCT-15 cells exposed up to 50 µg/mL concentrations for 24 h. It is evident from our finding that the underlying mechanism of cell death in cancer cells exposed to AM-Ag NPs was intrinsic apoptosis pathway mediated by activation of caspase-3 and p53 genes. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles (Ag NPs) by both ripe and unripe fruit extract was carried out by an important medicinal plant Tinospora cordifolia. The ripe and unripe fruit extract mediated bioinspired Ag NPs showed surface plasmon resonance (SPR) band at 431 and 421 nm respectively and confirmed the formation of Tc-Ag NPs. The functional groups of bioactive components of ripe and unripe fruits were identified which reduced silver nitrate to silver ions by Fourier-transform infrared spectroscopy (FTIR). The size distribution of biosynthesized Tc-Ag NPs of ripe and unripe was determined by particle size analyzer which revealed that the Z average of Tc-Ag NPs was around 30- 35 nm ± 1 nm and 30-35.8 nm ± 1 nm with an Z average of 25.9 and 28.5 nm respectively. Tc-Ag NPs exhibited stability due to its high negative zeta potential for both ripe and unripe fruit extract mediated Tc-Ag NPs as of -27.2 and -24.6 mV. Tc-Ag NPs were used to evaluate the antibacterial, antioxidant and catalytic activities. The Tc-Ag NPs revealed good antimicrobial activity. Antibiotic erythromycin was used as a standard in the present study. The Tc-Ag NPs of both ripe and unrippen fruits disclosed greater free radical scavenging efficacy which proved to be potent antioxidant agents and also exhibited potential catalytic activity by converting 4 nitro-phenol to 4 amino phenols at rapid pace. It was concluded that the Tc-Ag NPs synthesized by ripe and unripe fruits almost showed similar results, and so both of them proved to have excellent multifunctional biomedical properties. [ABSTRACT FROM AUTHOR]

This study extensively investigated to find out the in-vivo acute toxicity and lethal concentration (LC50) of biosynthesized Ag NPs in Labeo rohita (L. rohita). The haematological studies and antioxidative responses were considered in three tissues such as gill, liver and muscle of L. rohita. The results of this study showed that increasing the dose of Ag NPs led to bioaccumulation in the tissues. The haematological analysis showed considerable alterations in the Ag NPs-treated fish. The impact of histological changes induced by Ag NPs were confirmed by the damages in the tissues, primary lamella, blood vessels and formation of vacuolation in liver and muscle when compared with the control L. rohita. [ABSTRACT FROM AUTHOR]

In this study, we aim to fabricate a silver nanoparticles (Ag NPs) based electrochemical biosensor for Japanese Encephalitis virus antigen detection. Ag NPs were deposited onto screen-printed carbon electrode (SPCE) and the electrochemical properties of the Ag NPs modified SPCE were investigated via electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). It was observed that the deposition of Ag NPs onto electrode surface has significantly enhanced the conductivity up to 20.5% than that of bare SPCE. The EIS data indicated limit of detection (LOD) of 2.60 ng/mL (at S/N = 3) towards JEV antigen, with an analysis assay time of 20 min. This presented Ag NPs modified SPCE has demonstrated a promising and rapid alternative to conventional biosensing techniques towards JEV antigen. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have been considered a powerful antimicrobial agents recently especially after increasing incidence of diseases associated with biofilm and multi-drug resistant pathogens required to find a novel path to eradicate that challenge. The present study aims to evaluate the antibacterial activity of biosynthesized silver nanoparticles (AgNPs) using a cell-free extract of Enterobacter cloacae and chemo synthesis by sodium borohydride (NaBH4) on biofilm-forming Pseudomonas oryzihabitans. Antimicrobial effect of silver nanoparticles in both types and in combination with imipenem were evaluated by agar well diffusion method. The results revealed a good response to inhibit biofilm-forming Pseudomonas oryzihabitans growth by silver nanoparticles antibacterial activity in both types (biological and chemical) and in combination with imipenem; the antimicrobial effect was increased and enhanced. In the present study, it was found that the biological and chemical silver nanoparticles were considered a novel and decisive solution against biofilm and multi-drug resistance bacteria with a preference of biological silver nanoparticles. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have been considered as powerful antimicrobial agents recently, especially with the increasing incidence of diseases associated with biofilm and multi-drug resistant pathogens. The aim of this study was to synthesize silver nanoparticles by biological and chemical methods and combination with imipenem to eradicate biofilm-forming bacteria at phenotypic and genotypic levels. The biosynthesis of silver nanoparticles was done by using Enterobacter cloacae (cell-free suspension) while chemosynthesis was conducted using sodium borohydride. Biological and chemical silver nanoparticles were characterized by ultraviolet-visible spectrophotometry which showed absorbance peak at 400 and 390nm respectively. Fourier transformer infrared analysis revealed that carboxylic and polyphenolic groups were coated on surface of both silver nanoparticles. Scanning electron microscope and size analyser showed that the sizes of biologically and chemically silver nanoparticles were 63 nm and 25 nm, respectively. In addition, it showed the formation of cubical nanoparticles. The antimicrobial effect of synthesized silver nanoparticles were evaluated by agar well diffusion and macrodilution method to determine minimum inhibitory concentration value. The results showed that biological silver nanoparticles were more effective on biofilm forming bacteria (Serratia fonticola and Pantoea sp.) than chemical synthesized ones. In addition, the combination effect between silver nanoparticles and imipenem displayed synergistic effect. Gene expression of biofilm encoding genes (smaI and esaL) were evaluated by real- time quantitative polymerase chain reaction (RT- qPCR) before and after treatment with silver nanoparticles in both types and imipenem and in combination between them. The results revealed that biological silver nanoparticles alone or in combination with antibiotics were more effective on biofilm gene expression by down regulation than other treatments. [ABSTRACT FROM AUTHOR]

In the present work, we investigated novel, green, and facile approach for the synthesis of stable silver nanoparticles by use of inexpensive and available Iraqi Zahdi palm dates extract as reducing and stabilizing agents. The formation and color change of dark brown suspension of silver nanoparticles were monitored and examined by ultraviolet-visible spectrophotometric analysis at maximum wavelength of 401 nm. The produced nanoparticles were characterized by dynamic light scattering (DLS), Fourier transform-infrared spectrometry (FTIR), atomic force microscope (AFM), X-ray diffraction (XRD) and scanning electron microscopy (SEM)-energy dispersive spectroscopy (EDS). The results demonstrated that particle size distribution was around 90 ± 40 nm which was in line with grain size of the nanoparticles measured by AFM, while the crystallite size was about 20 nm according to the results observed from XRD technique. Additionally, the zeta potential of synthesized silver nanoparticles was found to be nearly about -25 mV, whereby the suspension showed high stability upon storing the sample in a cool place for a long period of time. The synthesized silver nanoparticles exhibited efficient antibacterial activity against pathogenic methicillin-resistant Staphylococcus aureus (MRSA) bacteria. They also showed enhanced anticancer activity against breast cancer cells (MCF7) with high apoptotic effect as compared with normal MCF10A cells, which confirmed the biocompatible nature of green synthesized silver nanoparticles. It is considered that nanosilver particles synthesized with palm dates extract may basically establish a significant step to synthesize such nanoparticles for topical applications as well as an alternative anticancer drug of existing chemotherapeutics of cancer. [ABSTRACT FROM AUTHOR]

The synthesis of silver nanoparticles by using the stem extract and leaf extract of Sclerocarya birrea (Marula) and silver nitrate (AgNO3) is reported. The synthesized nanoparticles were characterized using ultraviolet-visible spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, dynamic light scattering, and visual inspection. The antibacterial activity of the synthesized nanoparticles was done by agar disc diffusion method and tested against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The ultraviolet visible absorption spectrum showed broad absorption band at around 430 nm corresponding to that of surface plasmon resonance of silver nanoparticles. The synthesis of silver nanoparticles was also confirmed by color change of AgNO3 to reddish brown upon addition of Sclerocarya birrea stem and leaf extracts. In addition, change in color of the solution from colorless to brown within 5 min at pH 11 showed that the rate of reduction was faster at this pH compared to lower pH. Transmission electron microscopy analysis proved that the synthesized nanoparticles were spherical in shape; energy-dispersive spectroscopy analysis confirmed the presence of silver in the synthesized nanoparticles; and dynamic light scattering confirmed that the stem nanoparticles were generally larger (36 to 58 nm) than those synthesized from leaf extracts (32 to 48 nm). These nanoparticles were found to possess potential antibacterial activity against E. coli and S. aureus. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) were synthesized through a green chemical approach using the piperine isolated from black pepper. The physicochemical properties of Triton X-100 coated silver nanoparticles (Triton X-100/Ag NPs) were well characterized by ultraviolet-visible absorption spectroscopy (UV-Vis), powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and energy dispersive X-ray spectroscopy (EDS). The TEM images confirmed the spherical shape of silver nanoparticles. The powder X-ray diffraction analysis revealed the silver nanoparticles exhibiting face-centered cubic (fcc) crystal structure with an average crystallite size of 15 nm. The cytotoxicity effects on HepG2 cells were also evaluated with a series of 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay. The effective toxic concentration of Triton X-100/piperine with silver nanoparticles was too low to damage HepG2 cells. The antibacterial activity results showed that the Triton X-100/piperine/AgNPs efficiently inhibited the two bacteria namely S. aureus and E. coli. The Triton X-100/piperine/AgNPs nanoconjugates were effective in inhibiting the growth of both gram-positive and gram-negative bacteria S. aureus and E. coli. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have particular properties that contribute to their very promising applications, novel in various fields of science, such as the development of biosensors, the diagnosis and treatment of cancer, the controlled release of drugs and the antimicrobial potential. The biological synthesis of nanoparticles is of great interest over other physical and chemical methods because the use of toxic chemicals and drastic reaction conditions are avoided. The extracellular biosynthesis using fungi could also make downstream processing much easier than the intracellular biosynthesis. One of the main applications of silver nanoparticles is their antimicrobial activity. Several studies have demonstrated the bactericidal properties of silver nanoparticles are different from silver ions, and that they are strongly influenced by their shape, size, concentration and colloidal state. In the present work, the ability of fungal strains from Uruguay to synthesize silver nanoparticles was studied. Eight fungi were able to synthesize nanoparticles. An extensive physicochemical characterization of the nanoparticles was carried out including ultraviolet-visible spectroscopy, transmission electron microscopy, dynamic light scattering, zeta-potential and gel electrophoretic mobility. According to the characterization and colloidal stability results, nanoparticles from three fungi were selected for antimicrobial activity assays. All nanoparticles were able to inhibit Escherichia coli growth, demonstrating their potential as effective antibacterial agent for use in biomedical applications. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles (NPs) by green route approaches has advantages over conventional methods. In green synthesis, we use eco-friendly plant extracts contain secondary metabolites and bioactive components, proteins that act as both reducing and capping agents, form stable and shape-controlled green silver nanoparticles. The current study deals with the synthesis of silver nanoparticles using the aqueous latex extract of Allamanda cathartica. The green silver nanoparticles are characterized by using different spectroscopic methods like ultra violet-visible spectroscopy (UV-Vis), Fourier transform-infrared spectroscopy (FTIR), transmission electron microscope (TEM), scanning electron microscope (SEM) and X-ray diffraction (XRD). Results indicated that the crystalline natured particles were spherical shaped with an average of 35 nm in size and that the stability of silver nanoparticles was due to its high negative zeta potential of -27.6 mV. The current study also revealed that green silver nanoparticles had very good genotoxic and cytotoxic activity in peripheral blood mononuclear cells (PBMCs). Leukemia leads to the development of high numbers of white blood cells, which is one of the major types of cancers that affect children. Many of the chemicals used for the treatment produce remarkable side effects. To overcome this problem, we made an attempt to see the efficacy of latex green silver nanoparticle on peripheral blood mononuclear cells and deoxyribonucleic acid fragmentation, which leads to the development of future therapeutic drugs. [ABSTRACT FROM AUTHOR]

Environmentally friendly green synthesis of nanomaterial has a very significant part in nanotechnology. In the present research, the synthesis of silver nanoparticles (AgNPs) was established by treating silver ions with the aqueous extract of Calligonum comosum green shoots at room temperature. AgNPs formation was firstly detected by the colour change of mixed extract (plant extract and AgNO3). Further characterization was done by ultraviolet, (UV)-Vis spectrophotometer, transmission electron microscopy (TEM), scanning electron microscopy (SEM), zeta potential and fourier transform infrared spectroscopy (FTIR). The peak values for UV-VIS-spectroscopy were in the range of 440 nm, TEM micrograph showed spherical shape for the particles and zeta potential showed formation of negative charged nanoparticles with an average size of about 105.8 nm. 1635.41 and 3249.83 cm-1 are the peaks detected from the FTIR analysis. In this study, biosynthesized silver nanoparticles mediated by C. comosum were tested for their antimycotic activity using a well diffusion method against fungal species; Aspergillus flavus, Penicillium sp, Fusarium oxysporum. Our findings indicated that biosynthesized AgNPs showed an efficient antimycotic activity against tested species. The antimycotic action of AgNPs varied according to different fungal species. Results confirmed the ability of C. comosum green shoot extract to act as an reducing and stabilizing agent during the synthesis of AgNPs. [ABSTRACT FROM AUTHOR]

In this study, an ecofriendly, green method for synthesis of silver nanoparticles (AgNP) has been developed using Mallotus tetracoccus (MT) leaves as a reducing agent. The formation of AgNPs was standardised at pH 7 and 60 °C. UV-visible spectroscopy showed the high peak of absorption band at 420 nm. By atomic force microscopic (AFM) and scanning electron microscopic (SEM) observations, the size of the silver nanoparticles was found to be in the range of 46 to 100 nm, with an average size of 73 nm. The energy dispersive x-ray spectroscopic (EDX ) profile of silver nanoparticles showed typical optical absorption peak approximately at 3 keV. FTIR spectroscopic study revealed that hydroxyl groups of phenols and carboxylic acids were involved in the formation of AgNPs. Through MTT assay, the cytotoxicity results showed that AgNPs were highly effective on human ductal breast carcinoma cell lines (T47D) (76.8 to 84.9%). Thus, the MT-synthesized NPs are said to possess significant anticancer activity on cancer cells and very less toxicity on normal cells, which suggests its further applications in medicine. [ABSTRACT FROM AUTHOR]

The effect of metal surfaces on the crystallization of lysozyme using the Metal-Assisted and Microwave-Accelerated Evaporative Crystallization (MA-MAEC) technique and a monomode microwave system is described. Our microwave system (is called the iCrystal system hereafter for brevity) is comprised of a 100 W variable power monomode microwave source, a monomode cavity, fiber optic temperature probes and digital cameras. Crystallization of lysozyme (a model protein) was conducted using the iCrystal system on four different types of circular crystallization plates with 21-well sample capacity (i.e., crystallization plates): (i) blank: a continuous surface without a metal, (ii) silver nanoparticle films (SNFs): a discontinuous metal film, (iii) iron nano-columns: a semi-continuous metal film, and (iv) indium tin oxide (ITO): a continuous metal film. Lysozyme crystals grown on all crystallization plates were characterized by X-ray crystallography and found to be X-ray diffraction quality. The use of iron nano-columns afforded for the growth of largest number of lysozyme crystals with a narrow size distribution. ITO-modified crystallization plates were deemed to be best of all the crystallization plates based on the observations that lysozyme crystals were grown at the shortest time (370 ± 36 minutes) with a narrow size distribution up to 460 m in size. [ABSTRACT FROM AUTHOR]

Utilization of renewable marine resources for the biosynthesis of metal nanoparticles is an innovative area in the current nanotechnology research. The present article reports a simple environmentally benign method for the synthesis of silver nanoparticles using aqueous extract of marine brown seaweed Padina Tetrastromatica, which act as both the reducing and stabilising agent. The formation, morphology and crystalline nature of the synthesised silver nanoparticles were determined using UV-Visible Spectroscopy, Transmission electron microscopy, Selected area electron diffraction and X-ray diffraction techniques. The surface plasmon resonance peak at 424 nm in the UV-Visible spectrum confirmed the formation of silver nanoparticles. The biosynthesised silver nanoparticles were almost spherical with an average size of 15 nm. Crystalline nature of silver nanoparticles is evident from the characteristic peaks in the X-ray diffraction pattern, bright circular spots in the selected area electron diffraction pattern and clear lattice fringes in the High resolution Transmission electron microscopy images. Fourier transform infrared spectroscopic analysis revealed the presence of functional bio active metabolites in seaweed extract which is responsible for the formation and efficient stabilization of the nanoparticles. The biosynthesised silver nanoparticles show excellent antimicrobial activity against Escherichia coli and Aeromonas hydrophila. They also show very good catalytic activity for the reduction of methylene blue in the presence of NaBH4 in aqueous medium. Thus the green synthesised nanoparticles are expected to be a promising candidate for the application in diverse fields. [ABSTRACT FROM AUTHOR]

To evaluate the bactericidal, and cytotoxicity properties of silver nanoparticles synthesized from root extract of Asparagus racemosus. The physical properties of these nanoparticles were characterized by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), XRD and UV-Vis spectrophotometric analysis. The biochemical properties were assayed by antibacterial study, cytotoxicity assay using cancer cell line. The formation of silver nanoparticles was confirmed by UV-VIS spectroscopic analysis which showed absorbance peak at 420 nm. X-ray diffraction photograph indicated the face centered cubic structure of the synthesized AgNPs. TEM has displayed the different dimensional images of biogenic silver nanoparticles with particle size distribution ranging from 30-50 nm. Silver particles are spherical in shape. The EDX analysis was used to identify the elemental composition of synthesized AgNPs. Antibacterial activity of the synthesized AgNPs against three Gram positive and Gram negative bacteria strains like Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa carried out showed significant zones of inhibition. The cytotoxicity study by AgNPs also showed cytotoxicity on ovarian cancer cell line PA-1. The present study confirms that the AgNPs have great promise as antibacterial, and anticancer agent. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles (AgNPs) was carried out using aqueous extract of Roheda (Tecomella undulata) at 60 °C in orbital shaking incubator. The variation in pH values and colour changes were observed within few minutes during reduction of silver nitrate (0.1 to 1 mM final concentration) in presence of plant extract and the capping of synthesized stable silver nanoparticles. The UV-Vis spectra of reaction mixture at different time intervals were recorded to monitor the formation of nanoparticles. The maximum absorption peak was observed near 430 nm indicating the formation of AgNPs. The particle size distribution was analysed through dynamic light scattering (DLS) and it was found that the peaks at 5.85 nm and 77.48 nm. Polydisperse Index (PDI) of synthesized AgNPs is 0.378 indicating that nanoparticles are stable even after nine months storage and uniform size range. The stability of biogenic silver nanoparticles was monititored through zeta potential measurement. The surface properties and size of the nanoparticles were studied through scanning electron microscopy and atomic force microscopy. The purity of the synthesized nanoparticle was confirmed by electron dispersive X-ray spectroscopy (EDS). Atomic force microscopy images indicated that height of the particle ranges from 3-18 nm. The results of various techniques indicated that these are silver nanoparticles synthesized using leaf extract of Tecomella undulata. [ABSTRACT FROM AUTHOR]

Development of environmentally benign methods for synthesis of nanoparticles is an evolving important branch of nanotechnology. In the present study we report a green method for synthesis of stable silver nanoparticles (SNPs) from aqueous leaf extract of Syzygium alternifolium an endemic medicinal plant to Southern Eastern Ghats. These green synthesized nanoparticles are characterized by using UV-VIS spectroscopy, FTIR, XRD, AFM, SEM with EDAX and TEM. The colour change from yellow to grey is observed upon synthesis and 448 nm peak was obtained from UV-VIS spectroscopic analysis. FTIR spectroscopic studies confirms that phenols and proteins of leaf extract is main responsible for capping and stabilization of these SNPs. Crystallographic studies from XRD indicated the SNPs are crystalline in nature and owing 44 nm size. High resolution and magnification studies with AFM, SEM and TEM analysis revealed that the nanoparticles are spherical in shape having the size range from 7 to 44 nm. EDAX pattern of synthesized SNPs showed 47.28 weight percentage of Ag metal in the sample indicate the purity of sample. Further, the antimicrobial studies of these green synthesized SNPs show high toxicity towards different bacterial and fungal isolates. The results revealed that the selected medicinal plant possess the potentiality towards the synthesis of narrow range nanoparticles also combat with the pathogens. [ABSTRACT FROM AUTHOR]