Small-sized Silver Nanoparticles Research Articles

Engagement of specific intracellular pathways in the inflammation-based reprotoxicity effect of small-size silver nanoparticles on spermatogonia and spermatocytes invitro cell models

Male infertility is a serious ongoing problem, whose causes have not yet been clearly identified. However, since human exposure to silver nanoparticles (AgNPs) has recently increased due to their beneficial properties, the present study aimed to determine the impact of small-size AgNPs on mouse spermatogonia (GC-1 spg) and spermatocytes [GC-2 spd(ts)] in vitro models as well as the ability of these nanostructures to induce inflammation. The results showed a significant dose- and time-dependent decrease in the metabolic activity in both cell models, which was correlated with an increase in the intracellular ROS level. Moreover, increased activity of caspase-9 and -3, together with enhanced expression of CASP3 and p(S15)-p53 proteins, was detected. Further studies indicated a decrease in ΔΨm after the AgNP-treatment, which proves induction of apoptosis with engagement of an intrinsic pathway. The PARP1 protein expression, the activity and protein expression of antioxidant enzymes, the GSH level, and the increased level of p-ERK1/2 indicate not only the engagement of DNA damage but also the occurrence of oxidative stress. The small-size AgNPs were able to induce inflammation, proved by increased protein expression of NF-κB, p-IκBα, and NLRP3, which indicate damage to spermatogonia and spermatocyte cells. Moreover, the PGC-1α/PPARγ and NRF2/Keap1 pathways were engaged in the observed effect. The spermatogonial cells were characterized by a stronger inflammation-based response to AgNPs, which may be correlated with the TNFα/TRAF2-based pathway. Summarizing, the obtained results prove that AgNPs impair the function of testis-derived cells by inducing the redox imbalance and inflammation process; therefore, these NPs should be carefully implemented in the human environment.

In Situ Anchoring of Small-Sized Silver Nanoparticles on Porphyrinic Triazine-Based Frameworks for the Conversion of CO2 into α-Alkylidene Cyclic Carbonates with Outstanding Catalytic Activities under Ambient Conditions.

The preparation of catalytic hybrid materials by introducing highly dispersed metallic nanoparticles into porous organic polymers (POPs) may be an ideal and promising strategy for integrated CO2 capture and conversion. In terms of the carboxylative cyclization of propargyl alcohols with CO2, the anchoring of silver nanoparticles (AgNPs) on functional POPs to fabricate efficient heterogeneous catalysts is considered to be quite intriguing but remains challenging. In the contribution, well-dispersed AgNPs were successfully anchored onto the porphyrinic triazine-based frameworks by a simple "liquid impregnation and in situ reduction" strategy. The presence of N-rich dual active sites, porphyrin and triazine, which acted as the electron donor and acceptor, respectively, offered a huge opportunity for the nucleation and growth of metal nanoparticles. Significantly, the as-prepared catalyst Ag/TPP-CTF shows excellent catalytic activity (up to 99%) toward the carboxylative cyclization of propargyl alcohols with CO2 at room temperature, achieving record-breaking activities (TOF up to 615 h-1 at 1 bar and 3077 h-1 at 10 bar). Moreover, the catalyst can be easily recovered and reused at least 10 times with retention of high catalytic activity. The possible mechanism involves small-sized AgNP-mediated alkyne activation, which may promote highly efficient and green conversion of CO2. This work paves the way for immobilizing metal nanoparticles onto functional POPs by surface structure changes for enhanced CO2 catalysis.

Small size silver nanoparticles loaded with glycoside rich portion of Boerhavia Diffusa Linn. promotes wound healing: in-silico and in-vivo studies.

Silver nanoparticles (Ag-NPs) are increasingly used in various fields, including medicine, owing to their unique physicochemical properties. Due to their smaller size, the contact with biological components is increased, and consequently, it performs better as an antibacterial and antimicrobial. In this study, the authors have focused on the synthesis of small-sized spherical silver nanoparticles (Ag-NPs) by a chemical reduction method using two different capping agents and concentrations of AgNO3 as a precursor. Additionally, various amounts of Glycoside Rich Portion (GRP) isolated from the roots of Boerhaavia diffusa L. were loaded onto synthesised Ag-NPs. Punarnavoside, a glycoside found in GRP, has been reported to have antifibrinolytic properties. The docking study of punarnavoside present in GRP has shown good binding affinity with various antifibrinolytic targets. The surface plasmon resonance band, particle size, polydispersity index, and zeta potential values have been used to analyse the interaction and kind of bonding between GRP and Ag-NPs. A batch of trisodium citrate (TSC)-capped Ag-NPs loaded with 0.1ml of 1% GRP solution showed particle size smaller than 50nm with a stable zeta potential value of -55.3mV. Fourier transform infrared spectroscopic results showed CO and C-O bonds in GRP interacted with Ag-NPs. A batch of TSC-capped GRP-loaded Ag-NPs (1%)-based gel was developed using carbopol as a polymer. The TSC-capped GRP-loaded silver nanogel had greater wound closure in rats, as observed during the histopathological studies in the excision wound model. The antifibrinolytic activity of GRP, when coupled with the antibacterial and bactericidal properties of silver, demonstrated an increased wound healing effect.

Biosynthesis, characterization, and investigation of antimicrobial and cytotoxic activities of silver nanoparticles using Solanum tuberosum peel aqueous extract

Metallic nanoparticle biosynthesis is thought to offer opportunities for a wide range of biological uses. The green process of turning biological waste into utilizable products gaining attention due to its economical and eco-friendly approach in recent years. This study reported the ability of Solanum tuberosum (ST) peel extract to the green synthesis of non-toxic, stable, small-sized silver nanoparticles without any toxic reducing agent utilizing the phytochemical components present in its structure. UV–visible spectroscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, flourier scanning electron microscopy, atomic force microscopy, transmission electron microscopy, and energy dispersive analysis X-ray confirmed the biosynthesis and characterization of silver nanoparticles. Also, dynamic light scattering and thermogravimetric analyses showed stable synthesized nanoparticles. The antibacterial activity of the biosynthesized silver nanoparticles was evaluated against four different bacterial strains, Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus) Bacillus subtilis (B. subtilis), and a yeast, Candida albicans (C. albicans) using the minimum inhibitory concentration technique. The cytotoxic activities were determined against Human dermal fibroblast (HDF), glioblastoma (U118), colorectal adenocarcinoma (CaCo-2), and human ovarian (Skov-3) cell lines cancer cells using MTT test. The nanoparticle capping agents that could be involved in the reduction of silver ions to Ag NPs and their stabilization was identified using FTIR. Nanoparticles were spherical in shape and had a size ranging from 3.91 to 27.07 nm, showed crystalline nature, good stability (−31.3 mV), and the presence of capping agents. ST-Ag NPs significantly decreased the growth of bacterial strains after treatment. The in vitro analysis showed that the ST-Ag NPs demonstrated dose-dependent cytotoxicity against cell lines. Based on the data, it is feasible to infer that biogenic Ag NPs were capped with functional groups and demonstrated considerable potential as antibacterial and anticancer agents for biomedical and industrial applications.

Suppression of sonic hedgehog pathway-based proliferation in glioblastoma cells by small-size silver nanoparticles in vitro.

Glioblastomas (GBs) are one of the most aggressive and invasive intracranial cancers. Recently, it has been postulated that, among other factors, the hedgehog (HH) pathway may be a key factor in this phenomenon. Moreover, it has been reported that small-size silver nanoparticles (AgNPs) are characterized by a high cytotoxic effect towards GBs. However, their effect on the sonichedgehog (SHH) pathway has never been demonstrated in any cancer cells. Therefore, the aim of the present study was to evaluate the impact of the anti-proliferative properties of 5-nm AgNPs on the SHH pathway in the GB cell line (U-87MG) in vitro. The results showed a time- and dose-dependent decrease in the metabolic activity in the U-87MG cells treated with AgNPs, with IC50 reaching 30.41 and 21.16µg/mL after 24h and 48h, respectively, followed by an increase in the intracellular reactive oxygen species (ROS) level. The co-treatment of the cells with AgNPs and Robotnikinin (SHH inhibitor) abolished and/or strengthened the effect of AgNPs, especially on the SHH mRNA levels and on the PCNA, PTCH1, Gli1, and SUFU protein levels. Interestingly, no changes in the level of ERK1/2, Akt, and SRC kinase protein expression were detected, suggesting a direct impact of AgNPs and/or ROS on the inhibition of the canonical SHH pathway. However, more studies are needed due to the increase in the mTOR protein expression after the treatment of the cells with AgNPs, as in the Robotnikinin treatment. In conclusion, small-size AgNPs are able to inhibit the proliferation of GB cells in vitro by suppressing the canonical SHH pathway.

Silver Nanoparticle-Incorporated Defect-Engineered Zr-based Metal-Organic Framework for Efficient Multicomponent Catalytic Reactions.

Small-sized silver nanoparticles are incorporated into a thiol-functionalized stable Zr-based metal-organic framework (MOF). Thiol functionalization has been carried out using 2-mercapto benzoic acid (2-MBA) as the modulator, which promotes defect formation in the MOF structure. The incorporation of silver nanoparticles aided by the silver-sulfur interactions in this defective MOF gives rise to catalytic activity. Its catalytic efficiency in the highly atom-efficient A3 coupling reaction has been studied for a variety of substrates with impressive recyclability. The synergistic effect of the electron-rich silver core and electron-deficient surface of the thiol-bonded silver nanoparticle is key for this catalytic reaction.

Investigation of Cytotoxicity of Biosynthesized Colloidal Nanosilver against Local Leishmania tropica: In Vitro Study.

Leishmaniasis is one of the biggest health problems in the world. Traditional therapeutic methods still depend on a small range of products, mostly chemically. However, the treatment with these drugs is expensive and can cause serious adverse effects, and they have inconsistent effectiveness due to the resistance of parasites to these drugs. The treatment of leishmanial disease has always been a challenge for researchers. The development of nanoscale metals such as silver has attracted significant attention in the field of medicine. The unique characteristic features of silver nanoparticles (AgNPs) make them effective antileishmanial agents. In recent years, green nanotechnology has provided the development of green nanoparticle-based treatment methods for Leishmaniasis. Although there are many studies based on green nanoparticles against Leishmania parasites, this is the first study on the antileishmanial effect of biosynthesized AgNPs using an aqueous extract of Eucalyptus camaldulensis leaves (AEECL) as a reducing agent of silver ions. Different parameters such as AgNO3 concentration, AEECL concentration, and reaction time were studied to investigate the optimum factors for the preparation of stable and small-sized silver nanoparticles. The spherical shape of colloidal nanosilver (CN-Ag) was confirmed by atomic force microscope (AFM) and scanning electron microscope (SEM) images with sizes of 27 and 12 nm, respectively. A high density of nanoparticles with a small size of 10 nm has been confirmed from dynamic light scattering (DLS) analysis. The zeta potential value of 23 mV indicated that colloidal silver nanoparticles were stable. The nano-tracker analysis (NTA) showed the Brownian motion of silver nanoparticles with a hydrodynamic diameter of 31 nm. The antioxidant property of CN-Ag was determined using the stable radical 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay. In this study, a significant cytotoxic effect of biosynthesized CN-Ag has been shown against Leishmania tropica parasites at low concentrations (1.25, 2.5, and 3.75 µg/mL). These results could be used as a future alternative drug or could be a supportive treatment for Leishmaniasis.

Lagenaria siceraria peel waste aqueous extract mediated silver nanoparticles for degradation of Congo red dye

Green chemistry involves design, manufacture, use and disposal of chemical products with minimal or no use or generation of hazardous products. With a growing outlook towards environmental sustainability, people are currently looking at conservation and protection of natural resources for the wellbeing and health of present and future generations. The use of biodegradable kitchen waste for the synthesis of silver nanoparticles is a method which adheres to the principles of green chemistry and environmental sustainability. In the present study, aqueous extract of biodegradable peel waste of Lagenaria siceraria has been used for the synthesis of environment friendly silver nanoparticles. The method reduces the cost involved, makes use of aqueous medium and non-toxic biodegradable ingredients for the synthesis of silver nanoparticles. Characterization of silver nanoparticles was carried out. Reaction parameters like concentrations of reacting species, ratio of reactants, temperature and reaction time were optimized using UV-Visible Spectrophotometry. The SPR band was found at 420 nm indicating the formation of spherical isotropic small sized silver nanoparticles in the size range of 10 to 50 nm. The characterization of the silver nanoparticles with XRD and TEM revealed the crystalline nature of the particles and their morphology. The silver nanoparticles have been employed in the degradation of water soluble benzidine based anionic diazo dye, Congo red dye, which is employed in textile dyeing. The silver nanoparticles acted as nano catalyst in the dye degradation process. The method can be further scaled up and employed for the treatment of industrial waste waters coming from textile industry.

Ag nanoparticles enhance immune checkpoint blockade efficacy by promoting of immune surveillance in melanoma

Immune checkpoint blockade (ICB) therapy, represented by programmed cell death protein 1 (PD-1) and its ligand (PD-L1) monoclonal antibodies (mAbs), has shown an obvious benefit for melanoma immunotherapy, but the overall response rate is still low. To find an effective combination therapy strategy, we successfully produced small size silver nanoparticles coated with sucrose (S-AgNPs) as potent adjuvants. The antitumor effects of S-AgNPs were tested in vitro and comparatively investigated in immunodeficient and immunocompetent mice with melanoma. Fluorescence-activated cell sorting and immunofluorescent staining analysis were conducted to identify the tumor microenvironments. The expression of PD-L1 in tumors was tested by multiple methods. The combination therapy and potential toxicity of S-AgNPs and PD-1 mAbs were assessed in melanoma-bearing mice. In our findings, S-AgNPs presented potent antitumor effects, good druggability and low systemic toxicity. Functionally, we found that S-AgNPs exhibited better antitumor effects in immunocompetent mice. Mechanistically, we showed that S-AgNPs suppress tumor cell proliferation by inducing cellular apoptosis and promote cytotoxic CD8+ T cell infiltration and activity. Preclinically, S-AgNPs showed excellent local antitumor activity and mild systemic immunotoxicity with PD-1 mAbs in the inhibition of melanoma proliferation, providing a novel clinical combination treatment strategy.

Investigating Chaperone like Activity of Green Silver Nanoparticles: Possible Implications in Drug Development.

Protein aggregation and amyloidogenesis have been associated with several neurodegenerative disorders like Alzheimer’s, Parkinson’s etc. Unfortunately, there are still no proper drugs and no effective treatment available. Due to the unique properties of noble metallic nanoparticles, they have been used in diverse fields of biomedicine like drug designing, drug delivery, tumour targeting, bio-sensing, tissue engineering etc. Small-sized silver nanoparticles have been reported to have anti-biotic, anti-cancer and anti-viral activities apart from their cytotoxic effects. The current study was carried out in a carefully designed in-vitro to observe the anti-amyloidogenic and inhibitory effects of biologically synthesized green silver nanoparticles (B-AgNPs) on human serum albumin (HSA) aggregation taken as a model protein. We have used different biophysical assays like thioflavin T (ThT), 8-Anilino-1-naphthalene-sulphonic acid (ANS), Far-UV CD etc. to analyze protein aggregation and aggregation inhibition in vitro. It has been observed that the synthesized fluorescent B-AgNPs showed inhibitory effects on protein aggregation in a concentration-dependent manner reaching a plateau, after which the effect of aggregation inhibition was significantly declined. We also observed meaningful chaperone-like aggregation-inhibition activities of as-synthesized florescent B-AgNPs in astrocytes.

SINTESIS NANOPARTIKEL PERAK (NPAg) DENGAN BIOREDUKTOR EKSTRAK BIJI JARAK PAGAR DAN KAJIAN AKTIVITAS ANTIBAKTERINYA

The redox analysis as indicated by a change in color from yellow to reddish-brown was measured at the optimum wavelength of 405 nm with the highest redox result of 480 nm obtained in the NPAg-S sample. The optimal absorption wavelength changes according to the characteristics of the NPAg produced, but is generally in the range of 400-500 nm. Analysis of the active groups with the FTIR instrument showed active groups (OH, CH aldehyde, vibrations of CN bonds in the amine group, amide I groups from proteins, and CO double bonds in the 4000-1500 cm-1) zone. Additionally, in the identification zone 1500-600 cm-1 the formation of CN bond vibrations and the presence of an amide I group from the protein was found. Photographs at 10.000 and 15.000x magnification showed that the morphology of the distribution of NPAg in the jatropha seed extract solution was polydisperse and in the form of fibrous balls with non-uniform particles and tended to agglomerate. The distribution and size of the particles measured using the Particle Size Analyzer (PSA) instrument showed that the particle size ranged from 33-116 nm. NPAg-S samples at two concentrations (1 and 2%) showed inhibitory activity for all types of Gram positive and Gram negative bacteria. Analysis of the particle size distribution using PSA showed that the particle size of the NPAg-S sample was 33.8 nm, which was smaller than the NPAg-K sample of 44.8 nm. Antibacterial activity is strongly influenced by the particle size of a sample. Small size silver nanoparticles have a large surface area to interact with bacteria as compared to large silver nanoparticles, thus they can provide a greater antibacterial effect.

Green synthesis of highly dispersed Ag nanoparticles on polydopamine-functionalized graphene oxide and their high catalytic reduction reaction

Herein, we introduce a tailored mussel-inspired concept to facilitate the sustainable immobilization of silver nanoparticles (Ag NPs), which are accepted for the effectiveness in controlling the silver nanoparticle density and morphology onto the surface of the graphene oxide sheets (GO). Immobilization of Ag NPs on polydopamine (PDOP) functionalized GO is performed via the self-polymerization of dopamine by a facile in situ reduction method. The catalytic ability of the as-synthesized [email protected] catalyst was searched for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as a class of widespread toxic organic pollutant. The dopamine-mediated graphene hybrid with Ag NPs exhibited excellent catalytic reduction activities due to promoting the electron transfer and the dispersion of small-sized silver nanoparticles imposed upon the surface of graphene. The resulting hybrid exhibited 15 times higher catalytic activity than that of the graphene/silver hybrid without any modification.

Green assembly of high-density and small-sized silver nanoparticles on lignosulfonate-phenolic resin spheres: Focusing on multifunction of lignosulfonate

In this work, sodium lignosulfonate (SL) was introduced in the hydrothermal preparation of phenol-formaldehyde (PF) resin sphere that was subsequently used as a green reducer and support for synthesis of Ag nanoparticles (Ag NPs). The results showed that the addition amount of SL had a remarkable effect on the size of the SL incorporated PF (SLPF) spheres and the smallest particle size was obtained when 20% of SL (based on phenol mass) was added. The addition of SL increased the surface area and negative charge of SLPF spheres, which enhanced the Ag NPs loading amount accordingly. Moreover, SL also prevented Ag NPs from aggregating effectively, resulting in the high-density loading of small size Ag NPs on the SLPF spheres. Therefore, the as-prepared Ag@SLPF composites exhibited significantly enhanced catalytic activities in the 4-nitrophenol reduction than that of SL-free Ag@PF. Besides, the Ag@SLPF catalyst demonstrated superior recyclability owing to strong anchoring between the Ag NPs and the support. Consequently, the work demonstrates the incorporation of SL enables the green formation of high-density and tunable Ag NPs on the SLPF support and then endows the composite catalyst with enhanced catalytic performance, which presents a promising value-added application of lignosulfonate for functional catalyst preparation.

Simple Controlling Ecofriendly Synthesis of Silver Nanoparticles at Room Temperature Using Lemon Juice Extract and Commercial Rice Vinegar

Silver nanoparticles were prepared in an ecofriendly manner at room temperature via the stepwise-modified Tollens route using the lemon juice extract and commercial rice vinegar. In this work, the lemon juice extract—a natural-origin chemical—was used as a reducing and stabilizing agent, and commercial rice vinegar was used to create a low acidic environment to control the silver nanoparticle growth via the stepwise method. The average dimension of silver nanoparticles was qualitatively evaluated through the UV-Vis spectra via the Mie theory. The X-ray diffraction and field emission scanning electron spectroscopy were employed to study the purity, the crystal structure, and the morphology of samples, respectively. Due to the weak activity and low purity of ecofriendly chemicals, the reaction and baking times strongly affect the preparation efficiency in obtaining small-size silver nanoparticles (∼40 nm). The highest efficiency was obtained with 24 h reaction time and 48 h baking time. The bimodal distribution of the size of silver nanoparticles was observed by UV-Vis analysis and field emission scanning electron microscopy. The obtained small-size silver nanoparticles (∼40 nm) have a uniform dimension. The quality of the obtained silver nanoparticles was evaluated through the conducting properties of silver paint made from ecosynthesized silver nanoparticles which showed a promising prospect to develop green-synthesized silver paint working at room temperature.

Small-size silver nanoparticles stimulate neutrophil oxidative burst through an increase of intracellular calcium levels

Small-size silver nanoparticles stimulate neutrophil oxidative burst through an increase of intracellular calcium levels

Sunlight-driven phytochemical synthesis of silver nanoparticles using aqueous extract of Albizia lebbeck (L) Benth

Silver nanoparticles were synthesized in aqueous solution using an ecofriendly, fast, and easy photochemical technique through the use of Albizia lebbeck (L) Benth seed (ALS) extract and sunlight. The phytochemical screening of ALS extract revealed the presence of reducing carbohydrates, and saponins. Also, infrared spectroscopy analysis of the ALS extract confirms the presence of functional groups, characteristics of these compounds. The experiments were conducted near noon during winter by exposing aqueous mixtures of silver nitrate and ALS extract to sunlight at 25 °C. The nanoparticles were characterized by optical absorption spectroscopy, Fourier-transform infrared spectroscopy, and scanning transmission electron microscopy. The nanoparticle formation was evaluated by following the temporal evolution of the absorbance. This data was analyzed using first-order kinetics, finding good correlation to the experimental data. The nanoparticle micrograph analysis shows narrow size distribution and acceptable polydispersity indices. The sunlight driven synthesis of silver nanoparticles using ALS extract is more effective to produce small spheroidal AgNPs than sodium citrate. In addition, ALS extract inhibits the growth of nanoparticles with different morphologies, even when both reducing agents are incorporated at the same time. The proposed methodology presents a reliable and sustainable way to obtain small-sized silver nanoparticles according to the principles of green chemistry.

Biofabrication of Silver Nanoparticles from Diospyros montana, Their Characterization and Activity Against Some Clinical Isolates

Very small-sized silver nanoparticles (Ag-NPs) have been synthesized from dried leaf extract of Diospyros montana in aqueous medium. They have been characterized by various spectroscopic techniques (UV-Vis, FTIR spectroscopy), SEM, TEM, and EDX analyses. Particle size has been analyzed by Zetasizer. Their antibacterial screening has also been done against nine pathogenic bacterial strains. Formation of Ag-NPs was confirmed from a sharp absorption peak at 421 nm in the UV-Vis region of the spectrum. Its FTIR spectrum showed sharp ʋ(C=O) at 1635 cm−1 due to the presence of quinonoid type molecule in the extract which undergoes decrease in intensity after NP formation. Although three types of NPs were detected, their average diameter was found to be 61.69 nm. The particles of largest size were in abundance. However, from TEM analysis, five different types of NPs varying in shape and size (7.44, 13.10, 18.20, 8.90, and 10.60 nm) have been detected. SEM analysis showed that NPs were irregular in shape. EDX analysis showed sharp signal for Ag-NPs which suggest their crystalline structure. Their antibacterial activity was done on nine different bacterial strains using agar well and disk diffusion method according to CLSI guidelines. Maximum activity of Ag-NPs was observed against Klebsiella pneuomoniae and Escherichia coli while moderate efficacy was seen in other bacteria. Resistant pattern was also observed against Streptococcus viridans and S. mutans. Our study suggests that Ag-NPs can act as an antibacterial agent.

Cyanobacterial extract-mediated synthesis of silver nanoparticles and their application in ammonia sensing.

Green route for silver nanoparticle synthesis has gained increasing attention. Cyanobacteria are one of the promising organisms to produce a number of secondary metabolites that are capable of reducing silver ions to small-sized silver nanoparticles. In the present study, we employed an aqueous extract of the cyanobacterium Haloleptolyngbya alcalis KR2005/106 isolated from a soda lake for biosynthesis of silver nanoparticles (AgNPs). The extract acted as a reducing agent for AgNPs synthesis and resulted formation of nanoparticles < 50nm in size. In this study, synthesis of AgNPs obtained only in the sample exposed to photosynthetically active radiation (PAR) while the synthesis of AgNPs was not observed in the samples kept in dark. The biogenic fabrication of AgNPs was carried out by optimizing several governing parameters such as concentration of the silver nitrate solution, pH, temperature, and amount of biomass. Results obtained through different analytical techniques revealed that cyanobacterial taxon H. alcalis isolated from saline-alkaline habitat is a potential candidate for biosynthesis of optimum-sized spherical AgNPs. Surface plasmon resonance (SPR) property of AgNPs was exploited for aqueous ammonia sensing and revealed that AgNPs synthesized using aqueous extract of cyanobacterium H. alcalis could be employed for colorimetric detection of dissolved ammonia for monitoring quality of water.

Rapid and Green Synthesis of Monodisperse Silver Nanoparticles Using Mulberry Leaf Extract

Abstract A simple, rapid and eco-friendly technique for the preparation of small-sized silver nanoparticles with narrow distribution from 5 nm to 15 nm was developed. Using silver nitrate as silver precursor, and mulberry leaves extract as both capping and reducing agent, silver nanoparticles were obtained at room temperature, without employing any other reducing and capping agents. The formation of silver nanoparticles was observed by the change of color from pale yellow to brown and the UV-vis absorption spectroscopy. The effects of reaction time, temperature, silver nitrate concentration and mulberry leaves extract amount were studied. The silver nanoparticles were characterized by transmission electron microscopy (TEM), UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). The results demonstrate that the obtained metallic nanoparticles are highly crystalline silver nanoparticles with a spherical shape and capped with extract. A possible formation mechanism was proposed. The method in this paper may be extended to synthesize other noble metal nanoparticles using renewable materials as capping and reducing agents.

Apoptosis, Necrosis and Cytotoxicity of Newly Emerging and Developing Precursor Hepatoblast and Neuroblast Stem Cells After Critical Cell and Nucleoli Core Penetration of Small Size Nano Silver

Background: The present study was conducted to examine apoptotic, cytotoxic and necrotic effects of small size silver nano particles on newly emerging and developing precursor hepatoblast and neuroblast stem cells of vital organs of pregnant Swiss Albino mice and their fresh born fetuses. (10 mother and 10 fetuses from each group including control) Colloidal silver nano were imposed in a stabilizer sodium borohydride environment with disaggregate agent polyvinyl pyrollidone via synthesis and defragmentation of silver nitrate crystal with few drops of 1.5 M sodium chloride (NaCl) solution causes the suspension to turn darker yellow, then gray as the silver nano particles aggregates. Material and method: The size of silver nanoparticles was measured by transmission electron microscopy (TEM), and dynamic light scattering. Zeta potential of silver nanoparticles was determined by laser Doppler micro electrophoresis. After exposing newly emerging and developing precursor hepatoblast and neuroblast stem cells of pregnant Swiss Albino mice (5 to 15 gestational age) and their fresh born fetuses to small size nanosilver for 8 to 24 h in serial 8 micro meter fresh tissue serial cryostat sections cytotoxicity, apoptosis and necrosis was measured by Acridine orange, DAPI, 1:250 dilution Ethidium Bromide and combination assay through con focal microscope view. Result: Cytotoxicity and Apoptosis in newly emerging and developing precursor hepatoblast and neuroblast stem cells of pregnant Swiss Albino mice and their fresh born fetuses were detected by Acridine orange, DAPI immune staining and double staining of both combination with propidium iodide also scattered necrosis detected in same in 1:250 dilution Ethidium Bromide and combination assay through con focal microscope view. In TEM and dynamic light scattering analyses, the sizes of nanosilver found varied from 2.75 nm to 20 nm. AgNps were 71.56 nm in hydrodynamic diameter with a zeta potential of -17.52 mV. The Acridine orange, DAPI, 1:250 dilutions Ethidium Bromide and combination assay resulted in an LC50 value of 30 µg/mL. Small size nanosilver caused cytotoxic, apoptotic and necrotic effects in a dose-dependent manner. (0.5, 1, 10 & 15 mg/kg/b. W.) The apoptotic effect of nanosilver was marked up to a concentration of 30 µg/mL. At higher concentrations, the apoptotic effect depleted while the necrotic effect became upraised. Conclusion: The results indicate that small size nanosilver with a zeta potential of -17.52 mV and hydrodynamic diameter of 71.56 nm with TEM diagnosed diameter 2.75 to 20 nm ranges can be used in vitro at concentrations of up to 30 to40 µg/mL.