Green Synthesis of Robust, Biocompatible Silver Nanoparticles Using Garlic Extract

Synthesis and pharmacological evaluation of Andrographolide and Ajwain as promising alternatives to antibiotics for treating Salmonella gallinarum infection in chicken

The emergence of antibiotic resistance in pathogenic bacteria, including Salmonella gallinarum, poses a significant challenge to poultry health and food safety. In response, alternative strategies are urgently needed to mitigate bacterial infections without exacerbating antibiotic resistance. Phytoremediation, a sustainable and environmentally friendly approach, harnesses the natural detoxification capabilities of plants to remediate contaminants. This study explores the potential of combined phytoremediation using Andrographolide, derived from Andrographis paniculata, and Ajwain derived from Trachyspermum ammi as promising alternatives to antibiotics for treating Salmonella gallinarum infection in poultry. Andrographolide, known for its potent antimicrobial properties, exhibits inhibitory effects while Ajwain, rich in bioactive compounds, possesses antimicrobial and immunomodulatory properties. By leveraging their combined phytoremediation potential, Andrographolide and Ajwain offer a multifaceted approach to combat Salmonella gallinarum within the poultry environment. The study employed a rigorous experimental design, including in vitro assessments of antimicrobial susceptibility, cytotoxicity, and optimal concentration determination. Following this, in vivo experiments were conducted using a chicken model infected with Salmonella gallinarum. Results demonstrated that the selected combinations effectively reduced mortality rates, alleviated clinical symptoms, and mitigated gross pathological signs associated with Salmonella infection. Gene expression studies indicated a downregulation of proinflammatory cytokines, underscoring potential implications of a combined phytoremediation strategy as an innovative and sustainable solution to address Salmonella gallinarum infections in poultry production systems.

LCMS Based Untargeted Metabolic Profiling Revealed a Strong Association of Nanoselenium Treated Sesame (Sesamum indicum) Seed Bioactive Compounds as Novel Potential Disease Targets- A Nano-bioinformatics Approach

The convergence of nanotechnology with bioinformatics and the study of plant secondary metabolites hold remarkable potential for transformative scientific breakthroughs. Synergy enables a deeper understanding of the biosynthesis and functions of plant secondary metabolites, unlocking avenues to engineer novel applications in areas like pharmaceuticals, agriculture, and sustainable materials. The present study was conducted to check the effect of plant-mediated selenium nanoparticles to improve the bioactive compounds in sesame. Three varieties of sesame (TS-5, TH-6, and Till-18) were sown and got treated with different concentration of selenium nanoparticles. On the basis of antioxidant, biochemical, and physiological parameters, best performing seed samples from crop were selected and subjected to UHPLC analysis. From all 276 identified metabolites, the top 20 differentially expressed bioactive, medicinally important compounds were subjected to Swiss target prediction, KEGG, and Metascape analysis to reveal drug targets, gene targets, cell targets, and disease targets. Swiss target prediction revealed that most of the drug targets had kinases as the highest target in all the bioactive metabolites, followed by nuclear transporters, cytochrome P450, and proteins associated with electrochemical channels. Metascape analysis revealed that most of the compounds had highest enrichment in non-canonical activation of NOTCH3 followed by regulation of hormone levels. Furthermore, DisGeNET analysis revealed that most of the metabolites had strong association with impaired glucose tolerance followed by myocardial ischemia and neuralgia. Tissue and cell accumulation analysis by PaGeneBase revealed the highest accumulation in the small intestine, colon, ovary, and DRG cells. The study concluded that selenium nanoparticles has an ability to improve certain medicinally important metabolites in sesame, coupled with bioinformatics tools which revealed a great insight into the potential of those compounds, and the information can further be used in future studies.

Metal nanoparticles to improve the heat resilience in wheat (Triticum aestivumL.)

This study evaluated the efficacy of phytogenic silver and zinc nanoparticles in improving heat resilience in various wheat varieties. The silver and zinc nanoparticles were synthesized using plant leaf extract and characterized using various techniques. Four wheat varieties (DBW187, Black Wheat, DBW 50, and PBW 621) were subjected to field trials. The random block design was used, and nanoparticles in different concentrations were applied at various growth stages and morphologically, and yield parameters were recorded. UV-vis spectroscopy spectral analysis showed peaks for Ag nanoparticles at 420 nm wavelength and Zn nanoparticles at 240 and 350 nm wavelength, depicting the preliminary confirmation of nanoparticle synthesis. Electron microscopic analysis (TEM and SEM) provided morphological insights and confirmed synthesis of fine-sized particle mostly in a range between 10 and 60 nm. Energy dispersive x-ray analysis confirmed the elemental composition of the synthesized nanoparticles, with Ag and Zn elements detected in their respective samples. It also confirmed the oxide nature of synthesized ZnNPs. Dynamic light scattering analysis provided size distribution profiles, indicating average sizes of approximately 61.8 nm for Ag nanoparticles and 46.5 nm for Zn nanoparticles. The concentrations of Ag and Zn nanoparticles in the samples were found to be 196.3 ppm and 115.14 ppm, respectively, through atomic absorption spectroscopic analysis. Fourier transform infrared spectroscopy analysis revealed characteristic functional groups present in the nanoparticles. The results of field experiments established that Ag nanoparticles at 75 ppm concentration exhibited the most significant enhancements in plant growth. Conversely, Zn nanoparticles at a 100 ppm concentration demonstrated the most substantial improvements in the growth and yield of heat-stressed wheat varieties. The study concludes that optimized concentrations of silver and zinc nanoparticles can effectively improve heat stress resilience in wheat. These findings are promising to enhance abiotic stress resilience in crops.

Hypothesizing the Green Synthesis of Tamoxifen Loaded Magnetic Nanoparticles for the Treatment of Breast Cancer

Breast cancer is the second leading cause of death all over the world and is not only limited to females but also affects males. For estrogen receptor-positive breast cancer, tamoxifen has been considered the gold-line therapy for many decades. However, due to the side effects associated with the use of tamoxifen, its use is only limited to individuals in high-risk groups and limits its clinical application to moderate and/or lower-risk groups. Thus, there is a necessity to decrease the dose of tamoxifen, which can be achieved by targeting the drug to breast cancer cells and limiting its absorption to other body parts. Artificial antioxidants used in the formulation preparation are assumed to upsurge the risk of cancer and liver damage in humans. The need of the hour is to explore bioefficient antioxidants from natural plant sources as they are safer and additionally possess antiviral, anti-inflammatory, and anticancer properties. The objective of this hypothesis is to prepare tamoxifen-loaded PEGylated NiO nanoparticles using green chemistry, tumbling the toxic effects of the conventional method of synthesis for targeted delivery to breast cancer cells. The significance of the work is to hypothesize a green method for the synthesis of NiO nanoparticles that are eco-friendly, cost-effective, decrease multidrug resistance, and can be used for targeted therapy. Garlic extract contains an organosulfur compound (Allicin) which has drug-metabolizing, anti-oxidant, and tumour growth inhibition effects. In breast cancer, allicin sensitizes estrogen receptors, increasing the anticancer efficacy of tamoxifen and reducing offsite toxicity. Thus, this garlic extract would act as a reducing agent and a capping agent. The use of nickel salt can help in targeted delivery to breast cancer cells and, in turn, reduces drug toxicity in different organs. This novel strategy may aim for cancer management with less toxic agents acting as an apt therapeutic modality.

Green synthesis of silver nanoparticles using Adhatoda vasica leaf extract and its application in photocatalytic degradation of dyes

The paper describes biogenic synthesis of silver nanoparticles (AgNPs) using Adhatoda vasica leaf extracts at room temperature. The prepared AgNPs were characterized by UV-visible spectroscopy, Fourier-transform infrared spectroscopy, powder X-ray diffraction, Energy dispersive X-ray (EDX), High Resolution Transmission Electron Microscope, Scanning Electron Microscopy and Thermogravimetric analyser. The bio reduction method is devoid of any toxic chemicals, organic solvents, and external reducing, capping and stabilizing agent. The synthesized AgNPs had spherical shape with particle size ranging between 3.88 and 23.97 nm and had face centered cubic structure. UV-visible spectral analysis confirmed the formation of AgNPs with a characteristic surface plasmon resonance band at 419 nm. The EDX pattern revealed the presence of elemental Ag in AgNPs. The prepared AgNPs were used for degradation of Amaranth, Allura red and Fast green in aqueous medium, with ≥ 92.6% efficiency within 15 min using 5 mg of AgNPs. The optical bandgap, Eg value of 2.26 eV for AgNPs was found to be effective for rapid photocatalytic degradation of all the three dyes. The degradation process was observed to follow pseudo first order kinetics.

Green synthesis and characterization of silver nanoparticles for reducing the damage to sperm parameters in diabetic compared to metformin

The present study used physics to synthesize silver nanoparticles using aqueous extract of fresh garlic as reducing and as a stabilizing agent silver nitrate solution. This method has proven to be environmentally friendly and safe for the synthesis of stable silver nanoparticles. The acquisition of silver nanoparticles was confirmed by optical detection, that is, by changing the color of the liquid to transparent orange and then blackish brown. Then, the characterization was confirmed using other assays. In this study, it was found that the absorption peak of silver nanoparticles was at a wavelength of 420 nm and the particle size ranged between [50-350] nm. The surface roughness of silver oxide/silver nanoparticles was 9.32 nm with an average square roughness of 21.19 nm, and the energy dispersive spectra showed that the absorption peak was in the region of 3 keV, indicating that the nanoparticles contained crystalline silver. In this study, the stability of the silver nanoparticles was good, as ZP reached (- 19.5). The results confirm that the conductivity increases with the increase in frequency due to the high energy of the photons, which causes the electrons to vibrate in the energy levels and thus increase the energy in the mitochondria and increase the movement of sperm in the Diabetic mice treated with doses of silver nanoparticles. The toxic effect of silver nanoparticles has been evaluated in other studies, in addition to evaluating antioxidants, antifungals, treating cancer cells, regulating cholesterol levels, the effect of these nanoparticles on sex cells in pregnant female mice, heart tension, and many other tests. In this study, the activities and efficacy of silver nanoparticles on sperms were determined in male mice with diabetes caused by STZ, and the treatment period was long (35 days) so that the evaluation period was a complete life cycle of male sex cells and within a long period of time and at an average nano size. This has not been studied in other previous studies. The results indicate that the biosynthesis of silver nanoparticles using garlic plant led to positive results on sperm treatments by contributing to an increase in the number of sperm with reactivation and a decrease in abnormalities in addition to a decrease in mortality due to diabetes. This is evidence that the synthesis of silver nanoparticles using garlic plant size (50-350 nm) can treat impotence and be used in the future in the treatment of many diseases without side effects.

Green Ag/AgCl as an Effective Plasmonic Photocatalyst for Degradation and Mineralization of Methylthioninium Chloride

A green synthesis of Ag/AgCl with an exceptional SPR and photocatalysis property is greatly benefit to the environmental application especially pollutant removal. In this work, a novel green plasmonic photocatalysis of Ag/AgCl nanocatalyst using aqueous garlic extract (Allium Sativum L.) was successfully synthesized. The allicin and organosulfur compounds in the garlic can act as reducing agents in the green synthesis process. The nanocatalyst properties were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffractometer. The light-harvesting property was investigated by UV-vis absorption spectra which reveals its visible light absorption capability owing surface plasmon resonance behavior of Ag nanoparticles. The degradation and mineralization of methylthioninium chloride (MC) using this photocatalyst were evaluated under visible light and natural solar irradiation. Surface plasmon resonance of Ag nanoparticles and the presence of organosulfur from the garlic extract facilitated adsorption of MC onto the particle surface, promoting greater degradation. The photocatalytic reaction under visible light can be explained by the pseudo first-order pattern with the highest reaction rate of 0.5829 mg L−1 min−1 at pH 10. The photocatalytic activity of the Ag/AgCl under the natural sunlight reached 90% and 75% for MC and total organic carbon (TOC), respectively. The intermediate products detected during MC degradation under sunlight irradiation before final transformation to CO2, H2O, HNO3, and H2SO4 were also reported. The simplicity of Ag/AgCl green synthesis with the photocatalysis properties under visible light and sunlight can offer the convenience of applying these nanoparticles for pollutant removal in water treatment processes.

Antimicrobial Activities against Opportunistic Pathogenic Bacteria Using Green Synthesized Silver Nanoparticles in Plant and Lichen Enzyme-Assisted Extracts

Enzyme-assisted extraction is a valuable tool for mild and environmentally-friendly extraction conditions to release bioactive compounds and sugars, essential for silver nanoparticle (AgNP) green synthesis as capping and reducing agents. In this research, plant and fungal kingdoms were selected to obtain the enzyme-assisted extracts, using green synthesized AgNPs. For the synthesis, pseudo-cereal Fagopyrum esculentum (F. esculentum) and lichen Certaria islandica (C. islandica) extracts were used as environmentally-friendly agents under heating in an aqueous solution. Raw and enzyme-assisted extracts of AgNPs were characterized by physicochemical, phytochemical, and morphological characteristics through scanning and transmission electron microscopy (SEM and TEM), as well as Fourier transform infrared spectroscopy (FTIR). The synthesized nanoparticles were spherical in shape and well dispersed, with average sizes ranging from 10 to 50 nm. This study determined the total phenolic content (TPC) and in vitro antioxidant activity in both materials by applying standard methods. The results showed that TPC, ABTS^•+, FRAP, and DPPH^• radical scavenging activities varied greatly in samples. The AgNPs derived from enzymatic hydrolyzed aqueous extracts C. islandica and F. esculentum exhibited higher antibacterial activity against the tested bacterial pathogens than their respective crude extracts. Results indicate that the extracts’ biomolecules covering the AgNPs may enhance the biological activity of silver nanoparticles and enzyme assistance as a sustainable additive to technological processes to achieve higher yields and necessary media components.

Multifarious global flora fabricated phytosynthesis of silver nanoparticles: a green nanoweapon for antiviral approach including SARS-CoV-2

The progressive research into the nanoscale level upgrades the higher end modernized evolution with every field of science, engineering, and technology. Silver nanoparticles and their broader range of application from nanoelectronics to nano-drug delivery systems drive the futuristic direction of nanoengineering and technology in contemporary days. In this review, the green synthesis of silver nanoparticles is the cornerstone of interest over physical and chemical methods owing to its remarkable biocompatibility and idiosyncratic property engineering. The abundant primary and secondary plant metabolites collectively as multifarious phytochemicals which are more peculiar in the composition from root hair to aerial apex through various interspecies and intraspecies, capable of reduction, and capping with the synthesis of silver nanoparticles. Furthermore, the process by which intracellular, extracellular biological macromolecules of the microbiota reduce with the synthesis of silver nanoparticles from the precursor molecule is also discussed. Viruses are one of the predominant infectious agents that gets faster resistance to the antiviral therapies of traditional generations of medicine. We discuss the various stages of virus targeting of cells and viral target through drugs. Antiviral potential of silver nanoparticles against different classes and families of the past and their considerable candidate for up-to-the-minute need of complete addressing of the fulminant and opportunistic global pandemic of this millennium SARS-CoV2, illustrated through recent silver-based formulations under development and approval for countering the pandemic situation.

Graphical abstract

Synthesis of Ultrastable and Bioconjugable Ag, Au, and Bimetallic Ag_Au Nanoparticles Coated with Calix[4]arenes

Compared to gold nanoparticles, silver nanoparticles are largely underexploited for the development of plasmonic nanosensors. This is mainly due to their easy chemical degradation through oxidation, poor colloidal stability, and usually broad size distribution after synthesis, which leads to broad localized surface plasmon resonance bands. Coatings based on polymers such as poly(ethylene glycol) (PEG) or poly(vinylpyrrolidone) (PVP) and plant extracts have been used for the stabilization of AgNPs; however, these thick coatings are not suitable for sensing applications as they isolate the metallic core. The examples of stable AgNPs coated with a thin organic layer remain scarce in comparison to their gold counterparts. In this work, we present a convenient one-step synthesis strategy that allows to obtain unique gold, silver, and bimetallic NPs that combine all of the properties required for biosensing applications. The NPs are stabilized by a tunable calix[4]arene-based monolayer obtained through the reduction of calix[4]arene-tetradiazonium salts. These multidentate ligands are of particular interest as (i) they provide excellent colloidal and chemical stabilities to the particles thanks to their anchoring to the surface via multiple chemical bonds, (ii) they allow the subsequent (bio)conjugation of (bio)molecules under mild conditions, and (iii) they allow a control over the composition of mixed coating layers. Ag and Ag_Au nanoparticles of a high stability are obtained, opening perspectives for development of numerous biosensing applications.

Improving the bioavailability and bioactivity of garlic bioactive compounds via nanotechnology

This review highlights main bioactive compounds and important biological functions especially anticancer effects of the garlic. In addition, we review current literature on the stability and bioavailability of garlic components. Finally, this review aims to provide a potential strategy for using nanotechnology to increase the stability and solubility of garlic components, providing guidelines for the qualities of garlic products to improve their absorption and prevent their early degradation, and extend their circulation time in the body. The application of nanotechnology to improve the bioavailability and targeting of garlic compounds are expected to provide a theoretical basis for the functional components of garlic to treat human health. We review the improvement of bioavailability and bioactivity of garlic bioactive compounds via nanotechnology, which could promisingly overcome the limitations of conventional garlic products, and would be used to prevent and treat cancer and other diseases in the near future.

Silver Nanoparticles: Mechanism of Action and Probable Bio-Application

This review is devoted to the medical application of silver nanoparticles produced as a result of "green" synthesis using various living organisms (bacteria, fungi, plants). The proposed mechanisms of AgNPs synthesis and the action mechanisms on target cells are highlighted.

Green synthesis of antimicrobial silver nanoparticles using aqueous leaf extracts from three Congolese plant species (Brillantaisia patula, Crossopteryx febrifuga and Senna siamea)

In the present study, silver nanoparticles (AgNPs) were synthesized using aqueous leaf extracts of three Congolese plant species, namely Brillantaisia patula (BR-PA), Crossopteryx febrifuga (CR-FE) and Senna siamea (SE-SI). The obtained AgNPs were studied for their optical, structural, surface morphological and antibacterial properties. The prepared AgNPs were characterized by using UV-Visible spectra, Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray spectroscopy (EDX) and X-ray diffractometer (XRD). The synthesized nanoparticles were spherical shaped and well-dispersed with average sizes ranging from 45 to 110 nm. The AgNPs derived from BR-PA, CR-FE and SE-SI exhibited higher antibacterial activity against three bacterial pathogens of the human skin compared to their respective crude extracts and AgNO3. This indicated that the biomolecules covering the nanoparticles may enhance the biological activity of metal nanoparticles. Hence, our results support that biogenic synthesis of AgNPs from Congolese plants constitutes a potential area of interest for the therapeutic management of microbial diseases such as infectious skin diseases.

One-pot biosynthesis of silver nanoparticles with potential antimicrobial and antibiofilm efficiency against otitis media-causing pathogens

There are increasing demands for biogenic synthesis of silver nanoparticles (AgNPs) due to their unique properties and their numerous applications especially in biomedical field. Direct sunlight irradiation on aqueous garlic extract (AGE) represent fast, applicable, non-toxic, cheap, and ecofriendly method for (AgNPs) synthesis, with potentials to compete multi-drug-resistant (MDR) and biofilm-forming pathogens causing otitis media (OM). The aim of this study was to establish an eco-friendly method for synthesis of AgNPs, using aqueous garlic extract and sunlight, and moreover, detect its potential to inhibit MDR OM microbes. Obtained AgNPs were characterized by UV-visible spectral analysis, TEM, DLS, XRD, and FTIR. The effect of biosynthesized AgNPs on microbial growth, as well as biofilm productivity, was assessed against five resistant OM-causing strains, namely Bacillus cereus, Pseudomonas aeruginosa, Penicillium chrysogenum, Aspergillus niger, and Aspergillus flavus. Kirby-Bauer disc diffusion method was used to assess the inhibitory effect of 100, 50, 25, 12.5, and 6.25 μg/ml of AgNPs compared with tetracycline or nystatin and AGE. Additionally, the effect of 25 μg/ml of AgNPs on biofilm productivity of such strains was qualitatively assessed using Congo red agar (CRA) and TEM used to capture the changes inside the selected strains. The obtained AgNPs showed a highly significant (p value < 0.001) antimicrobial and antibiofilm activities against tested strains. TEM images of Pseudomonas aeruginosa and Aspergillus flavus treated with 25 μg/ml AgNPs showed shrinkage in the cytoplasmic materials and rupture of cell walls.

Pleurotus sajor-caju-Mediated Synthesis of Silver and Gold Nanoparticles Active against Colon Cancer Cell Lines: A New Era of Herbonanoceutics

Herbal medicines are widely used worldwide and much appreciated because of their fewer side effects and the ability to fight diseases at the root cause. Active ‘phyto’ ingredients require a scientific approach and a mechanism to distribute components at the target site for better therapeutic results. Nanotechnology, on the other hand, has created new hope for cancer treatment but is still far from being proven in clinical settings. This article combines a unique approach to synthesis with the use of Pleurotus sajor-caju, followed by microwave irritation of silver and gold nanoparticles that ensures the capping of the active phyto ingredient and further enhances the effects of nanomedicine to fight colon cancer, thus opening a new era of what we call herbonanoceutics. The article also compares the characteristics and properties of silver (Au) and gold (Ag) nanoparticles synthesized by an in house developed novel microwave-assisted rapid green synthesis method. The as-prepared Ag NPs and Au NPs were compared using ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). Our comparative study revealed that both assemblies display face-centred cubic structures (FCCs) and are nanocrystalline in nature. The advantage of the approach was that the sizes of gold and silver were identical in range with a similar distribution pattern. This has helped us to study the activity against colon cancer cell line (HCT-116) without incoherence since size plays a key role in the application. More specifically, morphological changes, cell viability, the production of reactive oxygen species (ROS) and the fragmentation of DNA have been further reported to assess better the results obtained with the two metals. Our results suggest that the newly adopted synthesis method may ensure the dual benefits from phyto ingredients which further enhances the effectiveness of advanced nanomedicine.

Antibacterial, Antibiofilm and Anticancer Activity of Biologically Synthesized Silver Nanoparticles Using Seed Extract of Nigella sativa

Silver nanoparticle (AgNP) based approaches using plant materials have been accepted as biomedical applications. The current study aimed to test the antibacterial, antibiofilm, and anticancer activity of silver nanoparticles synthesized by seed extract of Nigella sativa (Ns) as stabilizing and reducing agents. Characterization was done through UV–visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electronic microscopy (SEM), and transmission electronic microscopy (TEM) analyses. UV-Vis spectroscopy showed a specific silver plasmon peak at 400 nm and a quick color change was observed in the bio-reaction medium. Electron microscopic images of Ns-AgNPs identified as spherical in shape with varied size ranged between 8 and 80 nm and zeta potential analysis evidenced the particles stability and polydisperity. Antibiofilm activity of Ns-AgNPs was evident as at 12.5 µg/mL Ns-AgNps restricted the biofilm formation by 88.42% for Enterococcus faecalis, 84.92% for E. coli, 81.86% for Klebsiella pneumonia, 82.84% for Staphylococcus aureus, and 49.9% for Pseudomonas aeruginosa, respectively. Furthermore, biologically synthesized AgNPs showed the significant bacteriostatic and bactericidal activity. Even the lowest concentration of Ns-AgNps restricted the highest rate of inhibition against S. aureus (6.5 and 15 µg/mL) and E. faecalis (6.5 and 15 µg/mL). Antimicrobial activity of S. aureus and E. fecalis was more prominent than E. coli (15 and 30 µg/mL), K. pneumonia (15 and 30 µg/mL) and P. aeruginosa (30 and 60 µg/mL) respectively. Moreover, Ns-AgNPs revealed significant cytotoxic ability and substantially killed human breast cancer cell (HCC-712) viability. The results of current study advocate that Ns-AgNps may be considered as a potential option in biomedical applications, alternative therapy, designing anti-biofilm agents, treating multi drug resistance bacterial infection, and anti-cancer therapy.

Synthesis, characterization and antibacterial study of Ag-Au Bi-metallic nanocomposite by bioreduction using piper betle leaf extract

Biological reduction method using plant extract for the synthesis of metal and metal oxides are attracted much to the researchers due to its simplicity, which integrates the chemical technology. The special attention is given to the green synthesis of nanoparticles by easily available plants with eco-friendly system compared to other conventional methods. Silver-gold nanocomposite (Ag–Au NCp's) is synthesized by biological reduction of silver nitrate and gold chloride with biological reduction method. These metal salts are simultaneously reduced by betle leaf extract to form respective silver and gold nanocomposite. The structure and morphology of as prepared Ag–Au NCp's sample was characterized by employing powder X-ray diffraction (XRD) tool and by Scanning Electron Micrograph (SEM) tool respectively. Fourier Transform infrared (FTIR) spectral study was undertaken to know the bonding in the prepared silver sample. Energy dispersive X-ray analysis (EDX) study was undertaken to know the formation Ag–Au NCp's. Antibacterial studies are undertaken for the said nanocomposite to know its activity against bacteria.

Applications of near infrared and surface enhanced Raman scattering techniques in tumor imaging: A short review

Imaging technologies play a vital role in clinical oncology and have undergone massive growth over the past few decades. Research in the field of tumor imaging and biomedical diagnostics requires early detection of physiological alterations so as to provide curative treatment in real time. The objective of this review is to provide an insight about near infrared fluorescence (NIRF) and surface enhanced Raman scattering (SERS) imaging techniques that can be used to expand their capabilities for the early detection and diagnosis of cancer cells. Basic setup, principle and working of the instruments has been provided and common NIRF imaging agents as well as SERS tags are also discussed besides the analytical advantages/disadvantages of these techniques. This review can help researchers working in the field of molecular imaging to design cost effective fluorophores and SERS tags to overcome the limitations of both NIRF as well as SERS imaging technologies.

Biogenic Aspergillus tubingensis silver nanoparticles' in vitro effects on human umbilical vein endothelial cells, normal human fibroblasts, HEPG2, and Galleria mellonella

Silver nanoparticles (AgNPs) are widely incorporated into different hygiene, personal care, and healthcare products. However, few studies have been undertaken to determine the effects of biogenic AgNPs on human health. The effect of biosynthesized AgNPs using the fungus Aspergillus tubingensis culture was evaluated on human umbilical vein endothelial cells (HUVECs), normal human fibroblasts (FN1), human hepatoma cells (HEPG2) and a Galleria mellonella model. HUVECs were more susceptible to biogenic AgNPs than normal fibroblasts FN1 and intense cytotoxicity was observed only for very high concentrations at and above 2.5 μM for both cells. Normal human fibroblasts FN1 exposed to AgNPs for 24 h showed viability of 98.83 ± 8.40% and 94.86 ± 5.50% for 1.25 and 2.5 μM, respectively. At 5 and 10 μM, related to the control, an increase in cell viability was observed being 112.66 ± 9.94% and 117.86 ± 8.86%, respectively. Similar results were obtained for treatment for 48 and 72 h. At 1.25, 2.5, 5 and 10 μM of AgNPs, at 24 h, HUVECs showed 51.34 ± 7.47%, 27.01 ± 5.77%, 26.00 ± 3.03% and 27.64 ± 5.85% of viability, respectively. No alteration in cell distribution among different cycle phases was observed after HUVEC and normal fibroblast FN1 exposure to AgNPs from 0.01 to 1 μM for 24, 48 and 72 h. Based on the clonogenic assay, nanoparticles successfully inhibited HEPG2 cell proliferation when exposed to concentrations up to 1 μM. In addition to that, AgNPs did not induce senescence and no morphological alteration was observed by scanning electron microscopy on the endothelial cells. In the larvae of the wax moth, Galleria mellonella, a model for toxicity, AgNPs showed no significant effects, which corroborates to the safety of their use in mammalian cells. These results demonstrate that the use of A. tubingensis AgNPs is a promising biotechnological approach and these AgNPs can be applied in several biomedical situations.

Facile green synthesis and applications of silver nanoparticles: a state-of-the-art review

In the field of nanotechnology, the development of reliable and eco-friendly methods for the synthesis of NPs is crucial. The conventional methods for the synthesis of NPs are costly, toxic, and not ecofriendly. To overcome these issues, natural sources such as plant, bacteria, fungi, and biopolymers have been used to synthesize AgNPs. These natural sources act as reducing and capping agents. The shape, size, and applications of AgNPs are prominently affected by the reaction parameters under which they are synthesized. Accessible distributed data on the synthesis of AgNPs include the impact of different parameters (temperature and pH), characterization techniques (DLS, UV-vis, FTIR, XRD, SEM, TEM and EDX), properties and their applications. This review paper discusses all the natural sources such as plants, bacteria, fungi, and biopolymers that have been used for the synthesis of AgNPs in the last ten years. AgNPs synthesized by green methods have found potential applications in a wide spectrum of areas including drug delivery, DNA analysis and gene therapy, cancer treatment, antimicrobial agents, biosensors, catalysis, SERS and magnetic resonance imaging (MRI). The current limitations and future prospects for the synthesis of inorganic nanoparticles by green methods are also discussed herein.

Green Synthesis of Potent Antimicrobial Silver Nanoparticles Using Different Plant Extracts and Their Mixtures

Nano-sized metals have been introduced as a promising solution for microbial resistance to antimicrobial agents. Silver nanoparticles (AgNPs) have been proven to possess good antimicrobial activity. Green synthesis of AgNPs has been reported as safe, low cost and ecofriendly. This methodology uses extracts originating from different plants to reduce silver ions from AgNO3 into nano-sized particles. In this study, extracts of several plants including ginger, garlic, capsicum and their mixtures were successfully used to produce AgNPs. Numerous spectroscopic, light scattering and microscopic techniques were employed to characterize the synthesized AgNPs. Agar well diffusion assay was performed to investigate the antimicrobial activity of AgNPs. The biosynthesized AgNPs have spherical shape with a size range of 20–70 nm. Garlic extract, pure or in mixture with ginger extract, generated AgNPs of the smallest size. The presence of the plant-origin capping agents surrounding AgNPs was proven by Fourier-transform infrared spectroscopy. The AgNPs, at a concentration of 50 µg/mL, demonstrated potent antimicrobial activity against Staphyloccocus aureus, Escherichia coli and Candida albicans as indicated by the zones of. Our results revealed that AgNPs having potent antimicrobial activity could be prepared using different pure plant extracts and their mixtures.

Characterization and synergistic antibacterial potential of green synthesized silver nanoparticles using aqueous root extracts of important medicinal plants of Pakistan

In the past few years, biologically synthesized silver nanoparticles (AgNPs) have been standout amongst the most utilized nanoparticles both in the field of therapeutics and clinical practices. Therefore, the current study aimed to synthesize AgNPs for the first time using aqueous root extracts of important plants of Pakistan i.e. Bergenia ciliata, Bergenia stracheyi, Rumex dantatus and Rumex hastatus and characterize them. In addition, antibacterial activity of synthesized AgNPs at 30-150 μg/well was assessed using well diffusion method against Staphylococcus aureus, Staphylococcus haemolyticus, Bacillus cereus, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa bacterial strains that are considered most harmful bacteria for human beings. The characterization of synthesized AgNPs showed the absorption maxima ranged from 434 to 451 nm and XRD confirmed the crystalline nature of AgNPs as well as FTIR elucidated the involvement of biomolecules for reduction and capping of AgNPs. SEM determined the average size of AgNPs ranging from 25 to 73 nm and strong signals of silver were captured in EDX images. The result of antibacterial activity showed that only aqueous root extracts of all selected plants were inactive against all the tested bacterial strains. However, importantly, direct relationship between zone of inhibition of S. aureus, S. typhi and P. aeruginosa was found with increasing concentration of AgNPs of each selected plant. Moreover, S. haemolyticus was only inhibited by R. hastatus based AgNPs at only high concentrations and E. coli was inhibited by R. dantatus and R. hastatus based AgNPs. However, B. cereus was not inhibited by any AgNPs except R. hastatus and R. hastatus based AgNPs have greater antibacterial potential among all the synthesized AgNPs. These results suggest that synthesized AgNPs have improved antibacterial potential of root extracts of each selected plant and these synthesized AgNPs could be used in pharmaceutical and homeopathic industry for the cure of human diseases.

Comparing ex vivo and in vitro translocation of silver nanoparticles and ions through human nasal epithelium

Silver nanomaterials are widely used in clinically approved devices, consumer goods, and over-the-counter nutraceutical products. Despite the increase in silver nanomaterial research, few investigations have specifically distinguished the biological effects resulting from silver nanoparticles (AgNPs) versus silver ions released from AgNPs. This is in part, due to the complex analytical methods required to characterize silver ion release from AgNPs in biological media. This study sought to analyze silver ion release from AgNPs in biological media, compare silver transport from soluble AgNO₃ and AgNPs through ex vivo full thickness sinus human tissue explants and human nasal epithelium and determine fractional AgNP internalization by human nasal epithelial cells. Rapid silver ion release is observed from AgNPs in human nasal epithelial cell medium over 3 h (9.6% of total silver mass). Significantly lower translocation of AgNPs is observed through human nasal epithelial cell monolayers and ex vivo human sinus tissue explants compared to silver ion (AgNO₃). AgNP internalization is directly observed in AgNP-exposed human nasal epithelial cell monolayers by live cell scanning transmission electron microscopy (STEM), providing one potential mechanism for AgNP transcytosis. However, in vitro AgNP dissolution experiments suggest that silver in human nasal epithelium is primarily silver ion. Ionic AgNO₃ produces significantly higher silver translocation, supporting previous results claiming silver ion as primarily responsible for biological effects of AgNPs.

In vivo comparisons of silver nanoparticle and silver ion transport after intranasal delivery in mice

Silver nanoparticles (AgNPs) are widely available as consumer goods, and over-the-counter or nutraceutical products used for alleged therapeutic and antibacterial properties. Among these products, AgNP topical therapy is proposed for treating patients with upper airway bacterial rhinosinusitis. While silver ion release from AgNPs in biological systems is well known, limited investigations actually characterize this silver ion release and their subsequent biological effects distinct from delivered particulate metallic silver. This is in part due to the analytical complexity and difficulty involved in distinguishing silver ion release from metallic AgNPs in biological media. Therefore, this study compared intranasal administration of AgNPs versus soluble silver ion (AgNO₃) control to examine their transport and biological differences in tissues. First, we compared bactericidal activities of AgNPs and AgNO₃ in those bacteria commonly associated with clinical rhinosinusitis in vitro. Next, we evaluated silver residence time in the sinus cavity after intranasal delivery of AgNPs and AgNO₃ to mice, and characterized tissue distribution of silver in the sinonasal mucosal epithelium. We found that AgNPs show reduced bactericidal activity compared to AgNO₃ (i.e., MBC of 15ppm compared to 5ppm), and significantly lower residence times in the sinus cavity (AgNP concentrations of 3.76ppm after 3h compared to 9ppm for AgNO₃). AgNPs were not readily taken up into or through respiratory epithelium, with very low silver levels found in blood and no detectable silver measured in the olfactory bulb and brain. Results indicate that limited tissue distribution of silver detected from AgNPs is due to AgNP dissolution to silver ion. AgNPs therefore demonstrate adequate safety through limited penetration and absorption, but limited potential therapeutic efficacy as antimicrobials in nasal applications, as concentrations of silver in the sinus cavity drop below the minimum bactericidal concentration within 3h.

Green methods for the synthesis of metal nanoparticles using biogenic reducing agents: a review

Metal nanoparticles are being extensively used in a variety of sectors, including drug delivery, cancer treatment, wastewater treatment, DNA analysis, antibacterial agents, biosensors and catalysts. Unlike chemically produced nanoparticles, biosynthesized metal nanoparticles based on green chemistry perspectives impose limited hazards to the environment and are relatively biocompatible. This review is therefore focused on green methods for nanoparticle synthesis by emphasizing on microbial synthesis using bacteria, fungi, algae, and yeasts, as well as phytosynthesis using plant extracts. Furthermore, a detailed description of bioreducing and capping/stabilizing agents involved in the biosynthesis mechanism using these green sources is presented.

Green Synthesis and Characterization of Silver Nanoparticles Using Citrullus lanatus Fruit Rind Extract

The wide-scale application of silver nanoparticles (AgNPs) in areas such as chemical sensing, nanomedicine, and electronics has led to their increased demand. Current methods of AgNPs synthesis involve the use of hazardous reagents and toxic solvents. There is a need for the development of new methods of synthesizing AgNPs that use environmentally safe reagents and solvents. This work reports a green method where silver nanoparticles (AgNPs) were synthesized using silver nitrate and the aqueous extract of Citrullus lanatus fruit rind as the reductant and the capping agent. The optimized conditions for the AgNPs synthesis were a temperature of 80°C, pH 10, 0.001 M AgNO₃, 250 g/L watermelon rind extract (WMRE), and a reactant ratio of 4 : 5 (AgNO₃ to WMRE). The AgNPs were characterized by Ultraviolet-Visible (UV-Vis) spectroscopy exhibiting a λ_max at 404 nm which was consistent with the spectra of spherical AgNPs within the wavelength range of 380–450 nm, and Cyclic Voltammetry (CV) results showed a distinct oxidation peak at +291 mV while the standard reference AgNPs (20 nm diameter) oxidation peak occurred at +290 mV, and Transmission Electron Microscopy (TEM) revealed spherical shaped AgNPs. The AgNPs were found to have an average diameter of 17.96 ± 0.16 nm.

A review on green synthesis of silver nanoparticles and their applications

Development of reliable and eco-accommodating methods for the synthesis of nanoparticles is a vital step in the field of nanotechnology. Silver nanoparticles are important because of their exceptional chemical, physical, and biological properties, and hence applications. In the last decade, numerous efforts were made to develop green methods of synthesis to avoid the hazardous byproducts. This review describes the methods of green synthesis for Ag-NPs and their numerous applications. It also describes the comparison of efficient synthesis methods via green routes over physical and chemical methods, which provide strong evidence for the selection of suitable method for the synthesis of Ag-NPs.

Facile synthesis of multifunctional silver nanoparticles using mangrove plant Excoecaria agallocha L. for its antibacterial, antioxidant and cytotoxic effects

The current study describes a simple, rapid and eco-friendly method for the synthesis of silver nanoparticles (AgNPs) using Excoecaria agallocha (E. agallocha) leaf extract as stabilizer, bioreductant and capping agent. Synthesized AgNPs were characterized by UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX). Generation of AgNPs was initially confirmed with the color change from yellow to dark brown which produces intense absorbance spectra at 440 nm in UV-Vis spectroscopy without any shifting of peaks. Further, XRD pattern confirms that the synthesized AgNPs was face centered cubic (fcc) crystalline in structure with an average size of 20 nm. On the other hand, FTIR spectrum reveals that the active metabolites like water soluble phenolic compounds, flavonoids, methylene groups, amides and carboxylate groups. These active biocompounds plays a vital role in the reduction of Ag⁺ into their nanoscale values, it also acts as a stabilizing and surface functionalization agent. FESEM micrographs of synthesized AgNPs shows spherical and hexagonal shaped well dispersed particles in the dimension ranging between 23 and 42 nm. EDAX confirms the presence of silver (Ag) as the major constituent element without any impurities; also substantiate the stability of generated AgNPs. The biomedical insights of nanoparticles (NPs) were assessed through radical scavenging and antibacterial properties. Additionally, synthesized AgNPs was also exhibits an excellent cytotoxic effect against human breast carcinoma cell lines (MCF-7). This study proves that synthesized AgNPs can be developed as a potential nano-drug formulation to combat pathogenic disease and also for the expansion of breast cancer therapy.

DNA damage and mitochondria-mediated apoptosis of A549 lung carcinoma cells induced by biosynthesised silver and platinum nanoparticles

Therapeutic potential of the biosynthesised silver and platinum nanoparticles against lung carcinoma cell line. Cellular death was induced by oxidative stress followed by apoptosis.

Green Synthesis of AgNPs Stabilized with biowaste and their antimicrobial activities

In the present study, rapid reduction and stabilization of Ag+ ions with different NaOH molar concentration (0.5 mM, 1.0 mM and 1.5 mM) has been carried out in the aqueous solution of silver nitrate by the bio waste peel extract of P.granatum. Generally, chemical methods used for the synthesis of AgNPs are quite toxic, flammable and have adverse effect in medical application but green synthesis is a better option due to eco-friendliness, non-toxicity and safe for human. Stable AgNPs were synthesized by treating 90 mL aqueous solution of 2 mM AgNO₃ with the 5 mL plant peels extract (0.4% w/v) at different NaOH concentration (5 mL). The synthesized AgNPs were characterized by UV-Vis spectroscopy, TEM and SEM. Further, antimicrobial activities of AgNPs were performed on Gram positive i.e. Staphylococcus aureus, Bacillus subtilius and Gram negative i.e. E. coli, Pseudomonas aeruginosa bacteria. The AgNPs synthesized at 1.5 mM NaOH concentration had shown maximum zone of inhibition (ZOI) i.e. 49 ± 0.64 in E. coli, whereas Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilius had shown 40 ± 0.29 mm, 28 ± 0.13 and 42 ± 0.49 mm ZOI respectively. The MIC value of 30 μg/mL observed for E. coli Whereas, Staphylococcus aureus, Bacillus subtilius and Pseudomonas aeruginosa had shown 45 μg/mL, 38 μg/mL, 35 μg/mL respectively. The study revealed that AgNPs had shown significant antimicrobial activity as compared to Streptomycin.

Hepatoprotective and urease inhibitory activities of garlic conjugated gold nanoparticles

Garlic conjugated gold nanoparticles were successfully synthesized and their hepatoprotective potential was determined in a CCl₄-induced acute hepatic injury model.

Potential anticancer properties of bioactive compounds of Gymnema sylvestre and its biofunctionalized silver nanoparticles

BACKGROUND

Gymnema sylvestre is an ethno-pharmacologically important medicinal plant used in many polyherbal formulations for its potential health benefits. Silver nanoparticles (SNPs) were biofunctionalized using aqueous leaf extracts of G. sylvestre. The anticancer properties of the bioactive compounds and the biofunctionalized SNPs were compared using the HT29 human adenoma colon cancer cell line.

METHODS

The preliminary phytochemical screening for bioactive compounds from aqueous extracts revealed the presence of alkaloids, triterpenes, flavonoids, steroids, and saponins. Biofunctionalized SNPs were synthesized using silver nitrate and characterized by ultraviolet-visible spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, Fourier transform infrared spectroscopy, and X-ray diffraction for size and shape. The characterized biofunctionalized G. sylvestre were tested for its in vitro anticancer activity against HT29 human colon adenocarcinoma cells.

RESULTS

The biofunctionlized G. sylvestre SNPs showed the surface plasmon resonance band at 430 nm. The scanning electron microscopy images showed the presence of spherical nanoparticles of various sizes, which were further determined using the Scherrer equation. In vitro cytotoxic activity of the biofunctionalized green-synthesized SNPs (GSNPs) indicated that the sensitivity of HT29 human colon adenocarcinoma cells for cytotoxic drugs is higher than that of Vero cell line for the same cytotoxic agents and also higher than the bioactive compound of the aqueous extract.

CONCLUSION

Our results show that the anticancer properties of the bioactive compounds of G. sylvestre can be enhanced through biofunctionalizing the SNPs using the bioactive compounds present in the plant extract without compromising their medicinal properties.

Catalytically and biologically active silver nanoparticles synthesized using essential oil

There are numerous reports on phytosynthesis of silver nanoparticles and various phytochemicals are involved in the reduction and stabilization. Pure explicit phytosynthetic protocol for catalytically and biologically active silver nanoparticles is of importance as it is an environmentally benign green method. This paper reports the use of essential oil of Myristica fragrans enriched in terpenes and phenyl propenes in the reduction and stabilization. FTIR spectra of the essential oil and the synthesized biogenic silver nanoparticles are in accordance with the GC-MS spectral analysis reports. Nanosilver is initially characterized by an intense SPR band around 420 nm, followed by XRD and TEM analysis revealing the formation of 12-26 nm sized, highly pure, crystalline silver nanoparticles. Excellent catalytic and bioactive potential of the silver nanoparticles is due to the surface modification. The chemocatalytic potential of nanosilver is exhibited by the rapid reduction of the organic pollutant, para nitro phenol and by the degradation of the thiazine dye, methylene blue. Significant antibacterial activity of the silver colloid against Gram positive, Staphylococcus aureus (inhibition zone--12 mm) and Gram negative, Escherichia coli (inhibition zone--14 mm) is demonstrated by Agar-well diffusion method. Strong antioxidant activity of the biogenic silver nanoparticles is depicted through NO scavenging, hydrogen peroxide scavenging, reducing power, DPPH and total antioxidant activity assays.