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Intracellular biosynthesis of Au and Ag nanoparticles using ethanolic extract of Brassica oleracea L. and studies on their physicochemical and biological properties
Abstract
In this present study, we reported broccoli (Brassica oleracea L.) as a potential candidate for the synthesis of gold and silver nanoparticles (NPs) in green chemistry method. The synthesized metal nanoparticles are evaluated their antimicrobial efficacy against different human pathogenic organisms. The physico-chemical properties of gold nanoparticles were analyzed using different analytical techniques such as a UV-Vis spectrophotometer, Field Emission Scanning Electron Microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and a Fourier Transform Infrared spectrophotometer. In addition, gold and silver NP antimicrobial efficacy was checked by disc diffusion assay. UV-Vis color intensity of the nanoparticles was shown at 540 and 450nm for gold and silver nanoparticles respectively. Higher magnification of the Field Emission Scanning Electron Microscopy image shows the variable morphology of the gold nanoparticles such as spherical, rod and triangular shapes and silver nanoparticles were seen in spherical shapes. The average spherical size of the particles was observed in 24-38nm for gold and 30-45nm for silver NPs. X-ray diffraction pattern confirmed the presence of gold nanoparticles and silver nanoparticles which were crystalline in nature. Additionally, the functional metabolites were identified by the Fourier Transform Infrared spectroscopy. IR spectra revealed phenols, alcohols, aldehydes (sugar moieties), vitamins and proteins are present in the broccoli extract which are accountable to synthesize the nanoparticles. The synthesized gold and silver NPs inhibited the growth of the tested bacterial and fungal pathogens at the concentration of 50μg/mL respectively. In addition, broccoli mediated gold and silver nanoparticles have shown potent antimicrobial activity against human pathogens.
Copyright © 2015. Published by Elsevier B.V.
... In past few years, to promote the expansion of the commercial and industrial sectors, nanotechnology has generated a variety of goods with added value for use in daily life. Nanotechnology is a field that integrates the life sciences, and it has expanded to include nanomaterial creation and energy production [76,81]. It entails the fabrication, manipulation, characterization, production, and application of devices, systems, and structures by manipulating their size and shape on a nanoscale (1-100 nm) [116]. ...
... Recently, multiple biological substances such as plants, mushrooms, bacteria, and fungi have made more effort to synthesize nanoparticles using green chemistry approaches. Still, biologically mediated nanoparticles may manage a variety of acute and chronic disorders [12,76]. The green synthesis technique is practical, cost-effective, eco-friendly, and productive [16,23]. ...
... Several metal nanoparticles such as Gold (Au), Silver (Ag), Cobalt (Co), Palladium (Pd), Magnesium (Mg), Lead (Pb), Copper (Cu), Zinc (Zn), Manganese (Mn), and Iron (Fe) are employed in green synthesis [26]. Extracts from diverse plant parts, such as flower, leaves, stem, rhizome, bark, fruit, and seed, produce nanoparticles of varying shapes and sizes [76]. Especially, plants may create an abundance of secondary metabolites, including alkaloids, phenolic chemicals, and terpenoids. ...
Green chemistry refers to producing chemical products and processes that eliminate or minimize the production of harmful chemicals. In recent decades, chemical constituents, mainly plant secondary compounds, have been studied for their ability to develop green nanoparticles. The demand for green nanoparticle synthesis is increasing, and plant-mediated synthesis is gaining enormous popularity. The universal bioactive compounds of plants, such as alkaloids, terpenoids, flavonoids, and phenolics acids, play a crucial role in synthesizing nanoparticles. Green nanoparticles are found in items that come into touch with the human body and are employed in various scientific and pharmacological domains. Thus, the nanoparticles plant-derived secondary metabolites are environmentally friendly, inexpensive, more energy efficient, biocompatible method, safer, and less poisonous than their chemically manufactured counterparts. As a result, this sector is continuously evolving, and new techniques for enhancing the properties of green nanoparticles are continually being developed. The present chapter summarizes the latest findings in synthesizing green nanoparticles using plant-derived secondary metabolites. The procedures required to characterize produced green nanoparticles are also highlighted. Furthermore, this chapter discusses the benefits of green nanoparticles in various applications, including pharmaceutical and biomedical science, the food industry, cosmetics, agriculture, renewable energy, and wastewater treatment.KeywordsApplicationBiosynthesisMetabolites compoundsNanoparticlesVegetable
... cm −1 shows the asymmetric stretching vibrations (-CH2-) of their molecules and the stretching vibrations of the hydroxyl groups that constitute carbohydrates, respectively [37]. The absorption of C=C appearing at 1627.92 cm −1 indicates the presence of an alkene group [38]. A sharp peak at 1053.13 cm −1 assigned to C-O of pyranosyl ring [39]. ...
... A sharp peak at 1053.13 cm −1 assigned to C-O of pyranosyl ring [39]. Based on published FTIR spectra for particular chemical groups based on reference standards, these bands were previously identified [38]. As a result, the sample has seven clear spectral peaks at the range of 400 and 4000 cm −1 and these significant spectral peaks may help to obscure the functional groups of secondary metabolites. ...
Mycobacterium tuberculosis is a human pathogen that causes Tuberculosis (TB) disease. Researchers have reported the activity of traditional medicinal plants against human pathogens. However, antimycobacterial studies of medicinal plants against M. tuberculosis remain limited. Thus, the purpose of this study is to characterize the phytochemical profile, antibacterial and antimycobacterial activity of Tridax procumbens towards H37Rv. The antibacterial activity was elucidated by the inhibitory zone formed around the disc by performing disk diffusion method. Tridax antimycobacterial activity measured by Microplate Alamar Blue Assay (MABA) infers the sample is sensitive to H37Rv at MIC (minimum inhibitory concentration) 600 µg/mL. BACTEC MGIT 960 DST identifies the sample is susceptible to H37Rv and Rifampicin resistant (RR). Antiproliferative, functional group determination and mechanism of action of secondary metabolites were performed by MTT, Fourier transform infrared spectroscopy (FTIR) and Gas Chromatography—mass spectrometry (GC–MS). The phytocompounds antimycobacterial efficacy is further supported by molecular docking data. The binding interactions of ligands with gyrA gene revealed (S,Z)-Heptadeca-1,9-dien-4,6-diyn-3-ol molecule as a prominent phytocompound with a binding affinity of -6.6 kcal/mol.
... Pure and modified surfaces of AuNPs with conventional antibiotics exhibit effective antibacterial activity against Gram-negative and Gram-positive bacteria through adhesion and penetration on the cell membrane. Moreover, AuNPs show antiviral activity through interaction with viral surface proteins [19,[68][69][70][71][72]. A review of each article about the use of modified AuNPs in dental materials is presented in Table 3. ...
... AuNPs can easily identify tumor cells or pathogenic microbial cells, due to specific environmental factors such as an acidic pH or hypoxic conditions [18,19,39,98,104]. AuNPs cause a drastic induction of cell cycle arrest and DNA damage [72]. Chitosan-AuNP-curcumin composites had pH-responsive controlled release behaviors that led to significantly improved drug delivery systems under localized acidic conditions [39]. ...
Gold nanoparticles (AuNPs) have gained significant attention in the biomedical field owing to their versatile properties. AuNPs can be customized by modifying their size, shape and surface characteristics. In recent years, extensive research has explored the integration of AuNPs into various dental materials, including titanium, polymethylmethacrylate (PMMA) and resin composites. This review aims to summarize the advancements in the application of modified AuNPs in dental materials and to assess their effects on related cellular processes in the dental field. Relevant articles published in English on AuNPs in association with dental materials were identified through a systematic search of the PubMed/MEDLINE, Embase, Scopus and ScienceDirect databases from January 2014 to April 2024. Future prospects for the utilization of AuNPs in the field of dentistry are surveyed.
... The SMe were used as reducing agents for the green synthesis of silver (green-AgNPs) and gold nanoparticles (green-AuNPs), as suggested by Ibrahim [22] and Kuppusamy et al. [23], respectively, with minor modifications. The best concentration and reaction conditions were established based on preliminary assays (data not shown), and green-NP preparation details are shown in Fig. 1. ...
... In addition, AgNPs and AuNPs synthesized with extracts from leaves of Mukia maderaspatana showed good activity; authors evaluated the microbial growth reduction at 0.35 mg mL −1 for bacteria and 0.47 mg mL −1 for fungi with the following results: Escherichia coli (77.3 to 5.2%), Enterococcus faecalis (77.4 to 10.2%), and Aspergillus niger (73.8 to 13.8%) [10]. Kuppusamy et al. [23] prepared silver and gold NPs with the ethanolic extract of Brassica oleracea that were evaluated at 50 µg mL −1 against bacteria, obtaining the following halo inhibition values: Salmonella enterica serovar Typhi (AuNPs = 9 mm; AgNPs = 11 mm) > Escherichia coli (AuNPs = 8 mm; AgNPs = 9 mm) ≅ Staphylococcus aureus > Bacillus subtilis (AuNPs = 6 mm; AgNPs = 7 mm). Similar values were obtained in this study for the green-AgNPs against E. coli and some S. aureus strains, but the green-AuNPs were inactive (Table 2). ...
Melanins are widely distributed biopolymers that exhibit important biological activities. However, fruit melanins have been scarcely studied. In this work, the antibiofilm, cellular antioxidant, anti-inflammatory, immunomodulatory, cytotoxic, and antimutagenic activities of soluble melanins (SMs) isolated from the Randia echinocarpa fruit (papache) were evaluated. The SMs inhibited biofilm formation in Staphylococcus aureus MDR and ATCC 43300 up to 60% at 1000 µg/mL; they presented a cellular antioxidant activity (60.02%) at 50 µg/mL, were immunomodulatory by increasing the peripheral blood mononuclear cells (PBMC) proliferation index (1.09 at 50 μg/mL), and inhibited HeLa cell proliferation by 77.39% (IC50 = 9.34 µg/mL). SMs were neither toxic nor mutagenic in the Salmonella Typhimurium YG1024 strain and inhibited the 1-nitropyrene mutagenicity by 30.2%. The biological activities of papache SMs support their potential to be used in nutraceutical and pharmaceutical formulations.
... The planet extracts of varying pH are then added to different solutions of varying silver salt that function as the metal precursor and then heated to synthesize AgNPs [84][85][86][87]. Plants like Lactobacillus acidophilus [88], Brassica oleracea [89], Arnicae anthodium [90], Sida cordifolia [91], Sida acuta [92], among others, have been recently employed to synthesize AgNPs from their extracts. ...
... Several studies confirm the successful antifungal activity of AgNPs against multiple fungal pathogens. AgNPs synthesized from plant extracts of Brassica oleracea have shown to display antifungal activities against Aspergillus and Pneumocystis with its inhibitory effects equivalent to fluconazole [89]. Similarly, extracts from the Cassia roxburghii have antifungal effects against A. fumigates, A. niger, A. flavus, Candida albicans, Penicillium sp., Curvularia sp., Rhizoctonia solani, and F. oxysporum [108]. ...
Silver nanoparticles (AgNPs) possess unmatched chemical, biological, and physical properties that make them unique compounds as antimicrobial, antifungal, antiviral, and anticancer agents. With the increasing drug resistance, AgNPs serve as promising entities for targeted drug therapy against several bacterial, fungal, and viral components. In addition, AgNPs also serve as successful anticancer agents against several cancers, including breast, prostate, and lung cancers. Several works in recent years have been done towards the development of AgNPs by using plant extracts like flowers, leaves, bark, root, stem, and whole plant parts. The green method of AgNP synthesis thus has several advantages over chemical and physical methods, especially the low cost of synthesis, no toxic byproducts, eco-friendly production pathways, can be easily regenerated, and the bio-reducing potential of plant derived nanoparticles. Furthermore, AgNPs are biocompatible and do not harm normally functioning human or host cells. This review provides an exhaustive overview and potential of green synthesized AgNPs that can be used as antimicrobial, antifungal, antiviral, and anticancer agents. After a brief introduction, we discussed the recent studies on the development of AgNPs from different plant extracts, including leaf parts, seeds, flowers, stems, bark, root, and whole plants. In the following section, we highlighted the different therapeutic actions of AgNPs against various bacteria, fungi, viruses, and cancers, including breast, prostate, and lung cancers. We then highlighted the general mechanism of action of AgNPs. The advantages of the green synthesis method over chemical and physical methods were then discussed in the article. Finally, we concluded the review by providing future perspectives on this promising field in nanotechnology.
... The antimicrobial AgNP is well known for its anticancer, antifungal, and antibacterial activities. [54][55][56][57] This is the time to test its antiviral capability against a novel coronavirus. The investigation of the antiviral ability of AgNPs is quite advanced compared to other antimicrobial agents. ...
Apart from transmission through the respiratory droplet, the surface contact route is another major mode of viral transmission. The recent pandemic is neither the first nor the last; hence, it is a big challenge for a surface engineer to combat the transmission of microbes and viruses through the contact route. In this topical review, we have comprehensively summarized the possible techniques of surface modification for making surfaces antiviral and the respective antiviral mechanisms. Will the anti-biofouling, superhydrophobic, structured surfaces be enough to roll down viruses with water droplets? If so, there could be critical dimensions of nanostructures that need to be fabricated using a precise micro-nano manufacturing method, and the same has been discussed in this review. The surface structuring using functional nanomaterials (copper and copper alloy, gold nanoparticles, silver nanoparticles, titanium dioxide, zinc dioxide, etc.) against different types of viruses and viruses belonging to the coronavirus family has been compared in detail with their merits and demerits. Finally, we foresee that among these surface modification techniques, the nanospike structures combined with an antiviral coating could be the most effective way to combat the transmission of viruses (e.g., COVID-19) through the contact route.
... Plant extracts are used in the production of NPs, which is an important in nanobiotechnology. To date, there are several publications on the green synthesis of NPs employing entire plant extracts, herbs, and cryptogams such as bryophyte, pteridophyte whole plan is used, Sargassum muticum (Rajesh et al., 2014), Brassica oleracea L. (Kuppusamy et al., 2015), Sida acuta (Idrees et al., 2018) and many more listed in table 12. ...
Millions of tons of metallic nanoparticles (MNPs) are synthesized each year and used in various fields like nano-enabled devices, personal care, medicine, food, and agriculture. The reaction chemicals and processes employed in the industrial synthesis of MNPs are well acknowledged to be hazardous to the environment.Green synthesis has been recommended as a means of minimizing the usage of harmful substances and adverse chemical modification in the synthesis of MNPs. Extracts of organic chemicals, microorganisms, plants and plant-derived materials have all been employed as reducing agents in green synthesis.One of the most efficient, easy, cost-effective, and environmentally acceptable techniques for reducing the usage of toxic chemicals is to employ plant extracts in the synthesis of MNPs. Several eco-friendly procedures for the fast production of MNPs have been reported by utilizing aqueous extracts of plant components including the leaf, bark, flower, peel, shoot, tuber, resin, roots etc.Every year, new scientific publications are released, with each one highlighting the advantages of the green methodover classic synthesis. However, over two decades after the preliminary reports about the new technique exploded, commercial production of green-synthesized nanoparticle (NPs) does not appear to have found a means to scale up. This review covers green MNPs synthesis from various plant extracts and their potential applications as antimicrobial agents covering the literaturesince 2015. While highlighting the use of MNPs in a variety of fields and the potential impact of phytochemicals associated in MNPs production.
... Osuntokun J. et al., reported the synthesis of CuO nanoparticles using aqueous extract of broccoli having size of 30-40 nm [11]. Similarly the synthesis of gold and silver nanoparticles were reported having particle size of 24-38 nm and 38-45 nm respectively [12]. Recently selenium nanoparticles with anti-carcinogenic properties were synthesized having an average particles size of 10-28 nm [13]. ...
Nanotechnology is a recent technology which is developing rapidly and it has a wide range of potential applications. It is the atomic-level tailoring of materials to achieve unique features that may be controlled for the intended purposes. Nanomaterials can be prepared via several physico-chemical methods but bioreduction of bulk to nanomaterials via green synthesis has developed as a viable alternative to physico-chemical methods in order to overcome their limitations. Plant-mediated nanomaterial synthesis has been found to be environmentally friendly, less costly, and safe with no use of chemicals for medicinal and biological applications where the nanoparticles purity is of major concern. Plant extract is used for the reduction of materials from bulk into nano scale instead of other toxic reducing agents used in chemical methods. The phytochemicals present the extract of plant not only facilitate the synthesis of nanomaterials but act as stabilizing and capping agent, also the shape and size of nanoparticles can be tailored by changing the nature and concentration of plant extract. The present chapter focuses on the green synthesis of nanoparticles mediated by various Brassica species and their potential medicinal and biological applications.
... These antioxidants played a major role in stabilizing the surface as well as increase the cytotoxicity of AgNPs. As mentioned before the most important phytochemical constituents responsible for the reduction and capping of silver nanoparticles as revealed by FTIR and phytochemical studies are alkaloids, flavonoids, tannins, terpenes and quinones as reported by Kuppusamy et al. [30]. ...
Nanobiotechnology involves extraction of reducing agents from biological sources and their application for synthesis of nanoparticles. This study is based on identification and purification of natural reducing agents in medicinal plants like Brassica oleracea var. italica to analyse their anti-cancerous potential against HeLa and THP-1. Biogenic reduction of silver nanoparticles was performed using these plant extracts by single step bottom up approaches. Colorless to red coloured solution and a peak at 417 nm in UV–vis spectroscopy confirmed the synthesis of AgNPs. Scanning Electron Microscopy confirmed the spherical nature of AgNPs whereas XRD confirmed the crystalline nature. PSA, SEM and Zeta potential analyzer confirmed the AgNPs with range of size between 14.53 and 38.15 nm with higher stability. AgNPs were treated with HeLa and THP-1 cell line. The % inhibition from AgNPs on HeLa cell line was found to be highest at 80 μl concentration (26.3 %) and lowest at 10 μl concentration (19.49 %) whereas on THP-1 cell line was found to be highest at 80 μl concentration (22.96 %) and lowest at 10 μl concentration (2.26 %).
... Silver nanoparticles (Ag-NPs) have been explored and applied as a therapeutic drug because of their unique physiochemical and physicochemical properties such as anti-inflammatory, anti-angiogenesis, antiplatelet, antifungal, anticancer, and antibacterial activities [92]. In addition, ag-NPs have gained increasing attention in the biological and medical fields due to their easy synthesis process. ...
The outbreak of COVID-19 has drastically affected the daily lifestyles of people globally where specific Coronavirus-2 transmits primarily by respiratory droplets. Structurally, the SARS-CoV-2 virus is made up of four types of proteins in which S-protein is indispensable among them, as it causes rapid replication in the host body. Therefore, the glycine and alanine composed of HR1 of S-protein is the ideal target for antiviral action. Different forms of surface-active PPEs can efficiently prevent this transmission in this circumstance. However, the virus can survive on the conventional PPEs for a long time. Hence, the nanotechnological approaches based on engineered nanomaterials coating on medical equipments can potentially prevent the dissemination of infections in public. Silver nanoparticles with tuneable physicochemical properties and versatile chemical functionalization provide an excellent platform to combat the disease. The coating of amine-functionalized silver nanoparticle (especially amine linked to aliphatic chain and trialkoxysilane) in its nanostructured form enables cloths trap and kill efficient. PPEs are a primary and reliable preventive measure, although they are not 100% effective against viral infections. So, developing and commercializing surface-active PPEs with trap and kill efficacy is highly needed to cope with current and future viral infections. This review article discusses the COVID-19 morphology, antiviral mechanism of Ag-NPs against SARS-CoV-2 virus, surface factors that influence viral persistence on fomites, the necessity of antiviral PPEs, and the potential application of amine-functionalized silver nanoparticles as a coating material for the development of trap and kill-efficient face masks and PPE kits.
... Protozoa Ag ions destroy the sporozoites by entering the oocyst and ultimately break the oocyst wall Cryptosporidium parvum [154] The effects of protein-coated AgNPs (14.6 nm, Collargol) have shown in the viability, oxidative stress, and gene expression levels of ciliates species Tetrahymena thermophila [155] Monera AgNPs are highly toxic to bacteria, often associated with ion release and induction of oxidative stress. AgNPs serve as an antibacterial against bacterial tension and thus avoids its horrendous impact Bacteria [156,157] Inhibition of bacterial growth increased permeability due to the formation of "pits" Escherichia coli [134] The interaction of the bacterial cell with AgNPs causes Proton Motive Force dissipation leading to the death of the cell Staphylococcus aureus [158] Generation of ROS Autotrophic nitrifying bacteria [147] AgNPs caused toxicity in the membrane when they attached with less than ten nm-sized NPs Salmonella typhi, Pseudomonas aeruginosa and Vibrio cholera [159] Fungi AgNPs show antifungal activity, which suppresses the growth of fungal cells Aspergillus Sp., Rhizoctonia solani, Sclerotinia sclerotiorum, S. Minor [160] Plant AgNPs changed/inhibited seed's germination, the surface area of leaf, morphology, biomass, and growth potential Spirodela polyrhiza [161] Metabolic disorders arise, foliar proline accumulation is caused by a decrease in the contents of sugar. Total protein and chlorophyll, elongation of shoots and roots become reduced ...
Silver nanoparticles (AgNPs) are commonly used in numerous consumer products, including textiles, cosmetics, and health care items. The widespread usage of AgNPs results in their unavoidable discharge into the ecosystem, which pollutes the aquatic, groundwater, sediments, and marine environments. These nanoparticles (NPs) activate the production of free radicals reactive species in aquatic organisms that interrupt the functions of DNA, cause mitochondrial dysfunction, and increase lipid peroxidation, which terminates the development and reproduction both in vivo and in vitro. The life present in the aquatic ecosystem is becoming threatened due to the release and exploitation of AgNPs. Managing the aquatic ecosystem from the AgNP effects in the near future is highly recommended. In this review, we discussed the background of AgNPs, their discharge, and uptake by aquatic organisms, the mechanism of toxicity, different pathways of cytotoxicity, and bioaccumulation, particularly in aquatic organisms. We have also discussed the antimicrobial activities of AgNPs along with acute and chronic toxicity in aquatic groups of organisms.
... Silver nanoparticles are considered a significant chemical drug because of their exceptional physicochemical and chemical characteristics along with other biological characteristics, namely antiinflammatory, antiplatelet, antifungal, angiogenesis, anti-cancer, and antibacterial actions [105][106][107][108]. Due to their high synthesis mechanism, silver nanoparticles receive a lot of attention in the medical as well as biological fields. ...
Background
On 31st December 2019 in Wuhan, China, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), was acknowledged. This virus spread quickly throughout the world causing a global pandemic. The World Health Organization declared COVID-19 a pandemic disease on 11th March 2020. Since then, the whole world has come together and have developed several vaccines against this deadly virus. Similarly, several alternative searches for pandemic disease therapeutics are still ongoing. One of them has been identified as nanotechnology. It has demonstrated significant promise for detecting and inhibiting a variety of viruses, including coronaviruses. Several nanoparticles, including gold nanoparticles, silver nanoparticles, quantum dots, carbon dots, graphene oxide nanoparticles, and zinc oxide nanoparticles, have previously demonstrated remarkable antiviral activity against a diverse array of viruses.
Objective
This review aims to provide a basic and comprehensive overview of COVID-19's initial global outbreak and its mechanism of infiltration into human host cells, as well as the detailed mechanism and inhibitory effects of various nanoparticles against this virus. In addition to nanoparticles, this review focuses on the role of several antiviral drugs used against COVID-19 to date.
Conclusion
COVID-19 has severely disrupted the social and economic lives of people all over the world. Due to a lack of adequate medical facilities, countries have struggled to maintain control of the situation. Neither a drug nor a vaccine has a 100% efficacy rate. As a result, nanotechnology may be a better therapeutic alternative for this pandemic disease.
... In addition, the green synthesis of nanoparticles provides many benefits, such as availability, low cost, biocompatibility, better manipulation, and control over crystal growth [29]. Several plants such as Ziziphora tenuior [30], Althaea officinalis [31], Tecomella undulate [32], Pulicaria gnaphalodes [33], Brassica oleracea L [34]., Quercus brantii [35], Ceropegia thwaitesii [36], and Withania somnifera [37] have been utilized to produce colloidal Ag-NPs. ...
Green synthesis of nanoparticles provides an advancement over chemical and physical methods given its cost-effectively, environment-friendly, facile, and suitability for large-scale industrial production. Due to their characteristics, silver nanoparticles are exploited in various fields such as developing electronic devices, biosensing platforms, catalysts, wastewater purification, biomedicine, antifungal, and antibacterial agent. In this study, silver nanoparticles (Ag-NPs) were synthesized using leaves extract of Biarum chaduchrum at ambient temperature, and characterized through transmission electron microscopy, particle size analyzer, and fourier transform infrared spectroscopy. The average size of synthesized Ag-NPs was estimated at 100 nm with a spherical shape. In addition, the antibacterial activity of nanoparticles against Staphylococcusaureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa was tested by minimum inhibitory concentration analysis. According to the results and observations, this procedure can be applied for large-scale synthesis of Ag-NPs and other notable metal nanoparticles with medicinal and industrial use.
... 11,12 Biosynthesis is a technique for different preparations of NPs. Various NP shapes are documented, whether spherical, 13 triangular, 14 or hexagonal, 15 and the color change in the colloidal solution is mostly observed. For example, the Au NP solution is dark red or purple and the Ag NPs colloid is often orange or brown; however, the color is influenced by the NP sizes. ...
A wide range of methods can be used for nature-inspired metallic nanoparticle (NP) synthesis. These syntheses, however, are ongoing in the presence of diverse mixtures of different chemical compounds, and all or only a few of these contribute to resultant particle properties. Herein, the linden (Tilia sp.) inflorescence leachate and pure citric and protocatechuic acids were chosen for Ag-AgCl nanoparticle (NP) synthesis, and the resultant particles were then compared. We focused on the following four issues: (1) preparation of Ag-AgCl NPs using the Tilia sp.-based phytosynthetic protocol, (2) analytical determination of the common phenolic, nonphenolic, and inorganic profiles of three Tilia sp. types from different harvesting locations, (3) preparation of Ag-AgCl NPs using a mixture of citric and protocatechuic acids based on chromatographic evaluation, and (4) comparison of Tilia-based and organic acid-based syntheses. Our research confirms that the Tilia organic and inorganic profiles in biomasses are influenced by the harvesting location, and the three sites influenced both the morphology and final NP size. Our processing method was uniform, and this enabled great Ag-AgCl NP reproducibility for each specific biomass. We were then able to prove that the simplified organic acid-based synthesis produced even smaller NPs than Tilia-based synthesis. These findings provide better understanding of the significant influence on NP final properties resulting from other organic acids contained in the linden.
... The SMe were used as reducing agents for the green synthesis of silver (green-AgNPs) and gold nanoparticles (green-AuNPs), as suggested by Ibrahim [22] and Kuppusamy et al. [23], respectively, with minor modifications. The best concentration and reaction conditions were established based on preliminary assays (data not shown), and green-NP preparation details are shown in Fig. 1. ...
Up to date, fruit melanins have not been employed to synthesize nanoparticles (NPs). Crescentia alata, Randia echinocarpa, and Vitex mollis fruit are used in traditional medicine, and their soluble melanins (SMes) have high antioxidant activity. These SMes were used to prepare silver (green-AgNPs) and gold (green-AuNPs) NPs and evaluate their antioxidant capacity (DPPH and FRAP), activity against human pathogens (bacteria and the parasite Hymenolepis nana), and toxicity (Artemia salina assay). All SMes were useful to synthesize green-AgNPs but only V. mollis SMe for green-AuNPs. Infrared spectroscopy, dynamic light scattering, and transmission electron microscopy (TEM) showed that SMe is on the green-NPs surface. TEM showed 13–31-nm spherical green-AgNPs and 2–16-nm spherical and cylindrical green-AuNPs. Green-AgNPs showed higher antioxidant (FRAP = 3.4–725.4 µmol TE g⁻¹; DPPH = 10.9–748.2 µmol TE g⁻¹) and antibacterial (MIC = 1.85–15 µg mL⁻¹; MBC = 3.7–30 µg mL⁻¹) activities than the chemical-NPs. Moreover, the green-NPs (25 mg mL⁻¹) were active against H. nana with the following times (min) (paralysis, death): green-AgNPs (10–40, 15–90) and V. mollis AuNPs (28, 40). The toxicity of the green-NPs (LC50 = 61.6 to > 1000 μg mL⁻¹) depended on the SMe employed in the preparation. V. mollis NPs were the less toxic: minimal toxicity for the AgNPs (LC50 = 826.91 μg mL⁻¹) and non-toxic for the AuNPs (LC50 > 1000 µg mL⁻¹). Thus, the SMes are useful to obtain green-NPs of high stability that showed activities against human pathogens, suggesting their potential to be used as alternative health treatments.
... Silver nanoparticles (AgNPs) have shown broad applications in the medical system, such as anti-inflammatory, anti-angiogenesis, antiplatelet, antifungal, anticancer, and antibacterial activities [139][140][141][142]. Nowadays, AgNPs have been reported as biomedical therapeutic agents, such as wound dressings and long-term burn care products and antibacterial lotions [143]; They also exhibit antiviral activities against influenza A virus, hepatitis B virus, human parainfluenza virus, herpes simplex virus, and human immunodeficiency virus [144,145]. ...
Phytopharmaceuticals have been widely used globally since ancient times and acknowledged by healthcare professionals and patients for their superior therapeutic value and fewer side-effects compared to modern medicines. However, phytopharmaceuticals need a scientific and methodical approach to deliver their components and thereby improve patient compliance and treatment adherence. Dose reduction, improved bioavailability, receptor selective binding, and targeted delivery of phytopharmaceuticals can be likely achieved by molding them into specific nano-formulations. In recent decades, nanotechnology-based phytopharmaceuticals have emerged as potential therapeutic candidates for the treatment of various communicable and non-communicable diseases. Nanotechnology combined with phytopharmaceuticals broadens the therapeutic perspective and overcomes problems associated with plant medicine. The current review highlights the therapeutic application of various nano-phytopharmaceuticals in neurological, cardiovascular, pulmonary, and gastro-intestinal disorders. We conclude that nano-phytopharmaceuticals emerge as promising therapeutics for many pathological conditions with good compliance and higher acceptance.
... AgNPs synthesized using leaf extract of Brassica oleracea efficiently controlled the development of two pathogenic fungal pathogens, Aspergillus and Pneumocystis, at 50μg/ml concentrations, with its inhibitory effect comparable to that of fluconazole (Kuppusamy et al., 2015). AgNPs synthesized from Cassia roxburghii leaf extract showed an excellent antifungal activity against five human fungal pathogens, A. fumigates, A. niger, A. flavus, Candida albicans, Penicillium sp., and three plant fungal pathogens, Curvularia sp., Rhizoctonia solani, and F. oxysporum (Balashanmugam et al., 2016). ...
The use of silver nanoparticles (AgNPs) against various pathogens is now being well recognized in the agriculture and health sector. Nanoparticles have been shown to exhibit various novel properties and these properties, on other hand, rely upon the size, shape, and morphology of these particles. Moreover, these physical characteristics enable them to interact with microbes, plants, and animals. Smaller-sized particles have shown more toxicity than larger-sized nanoparticles. AgNPs have shown growth inhibition of many fungi like Aspergillus fumigates, A. niger, A. flavus, Trichophyton rubrum, Candida albicans, and Penicillium species. According to the current hypothesis, AgNPs act by producing reactive oxygen species and free radicals, which cause protein denaturation, nucleic acid and proton pump damage, lipid peroxidation, and cell wall damage. Therefore, they alter the cell membrane permeability, causing cell death. This mini-review summarizes the use of silver nanoparticles against fungal pathogens and fungal biofilm in the agricultural sector.
... The trials and the obtained results for Placket-Burman design. 400-4000 cm À1 wavelength range with a resolution of 4 cm À1 (Kuppusamy et al., 2015). ...
Microbial levan has great potential as a functional biopolymer in different fields including foods, feeds, cosmetics, and the pharmaceutical and chemical industries. In this study, a good levan producer bacterial strain of Pseudomonas fluorescens strain ES, isolated from soil in Egypt, in a previous study, was used. Levan production by this strain was optimized using Plackett-Burman experimental design (PBD) to screen the critical factors of several process variables and Centered Central Composite Design (CCD) was applied to further estimation of the relationship between the variables and the response as well as optimization of the levels. Plackett-Burman (P-B) design showed a p-value 0.0144 less than 0.05 indicated the significance of the model. Sucrose, potassium dihydrogen phosphate, yeast extract and pH value showed the most significant effect on the levan concentration at the values of 89.17, 65.83, 24.17, and 15.83, respectively. The purified levan polymer was characterized using different Physico-chemical methods such as Fourier Transform Infrared Spectrometer (FTIR), Nuclear magnetic resonance (NMR), and High-Performance Liquid Chromatography (HPLC) to determine the main composition and functional groups in the obtained polymer. HPLC results indicated that the polymer purification increased the percentage of fructose residue from 75 up to 89. Furthermore, ¹H and ¹³C NMR spectroscopy analysis showed great matching between the obtained signal for our polymer with that reported in other people’s work. The obtained levan polymer exhibited cytotoxic activity against Human epidermoid Skin carcinoma and Hepatocellular carcinoma with IC50 of 469 and 222.7 µg/ml, respectively. Antioxidant activity was determined using DPPH assay and the percentage of inhibition at 1000 µg/ml was found to be < 50 (13.89 ± 1.07) with IC50 of (24.42 ± 0.87).
... The nanoparticles prepared by green sources are used as stabilizing and capping agents (Chandra et al. 2020) (Das and Karankar 2019). The most used nanoparticles in biomedical application, which are gold, and silver nanoparticles are prepared by the green route (Kuppusamy et al. 2015) (Salem and Fouda 2020). Using various plant extracts, mono-, di-, and tri-metallic nanoparticles were prepared but still have some limitations in the state of aggregation, stability, and crystal growth (Guimarães et al. 2020) (Gomathi et al. 2020). ...
Novel corona virus (COVID-19) pandemic in the last 4 months stimulates the international scientific community to search for vaccine of antiviral agents suitable for in activating the virus inside and outside the human body. More than 4 million people globally are infected by the virus and about 300,000 dead cases until this moment. The ventilation and airborne filters are also investigated aiming to develop an efficient antiviral filtration technology. Human secretion of the infected person as nasal or saliva droplets goes as airborne and distributes the virus everywhere around the person. N95 and N98 filters are the must use filters for capturing particles of sizes around 300 nm. The average size of the novel corona virus (COVID-19) is 100 nm and there is no standard or special filter suitable for this virus. The nanoparticle-coated airborne filter is a suitable technique in this regard. While the efficiency of this type of filters still needs to be enhanced, new developed nanofiber filters are proposed. Most recently, the charged nanofiber filters of sizes below 100 nm are developed and provide an efficient viral filtration and inactivation. The efficiency of filter must be kept at accepted level without increasing the pressure drop. The present review outlines the most efficient antiviral nanoparticles including the recent functional nanoparticles. The filtration theory, filtration modeling, filter testing, and different types of filter with special concentration on the charged nanofiber filter were discussed. The charged nanofiber filter able to capture novel corona virus (COVID-19) with 94% efficiency and a pressure drop less than 20 MPa.
... Leaves or edible parts of cauliflower, potato, and pea are used for the synthesis of Au, Ag, and ZnO NPs [19][20][21][22][23][24][25][26][27][28][29] but an article for CuO synthesis by using peels of these vegetables and application as an antibacterial agent was not found. The sol-gel method is used to study the effect of the extract on the morphology of NPs. ...
The Greener synthesis of nanoparticles (NPs) is gaining importance due to its ease and economy. One-pot production of NPs utilizing vegetable peels is purely green. The current study reports the use of cauliflower (Brassica oleracea), potato (Solanum tuberosum), and pea (Pisum sativum) peels extract for the synthesis of copper oxide (CuO) NPs. An ecofriendly approach is established by performing synthesis in an aqueous medium, along with minimum use of chemicals, and low fabrication temperature. FTIR peaks for self-assembled Cu–O bond are found at 526 cm−1, 590 cm−1, and 582 cm−1 for calcined NPs made from cauliflower, potato, and pea extract accordingly. By using CuCl2·2H2O, the particle size of NPs is 32.5 nm, 40.7 nm, and 47.2 nm from cauliflower, potato, and pea peels, respectively. Moreover, differences in NPs shape like roughly spherical and cubical indicate the impact of phytochemicals during construction. Furthermore, this study is an exploration of the antibacterial efficacy of NPs. The inhibitory action of CuO NPs at 45 µg/mL was figured out as Pseudomonas aeruginosa > Escherichia coli > Bacillus subtilus > Staphylococcus aureus. A more significant biocidal effect of NPs was found on the growth of Gram-negative than Gram-positive bacteria. NPs are found superior for inhibition and inactivation of cell growth than NPs parent material against control. The current study presents biowaste management and its conversion to a useful product.
... In general, physical and chemical methods of NP synthesis are not environmentally friendly; they may contaminate different environments because of the use of reducing and stabilizing agents and the huge amounts of energy employed (Bhaduri et al., 2013). 3. Conversely, the biological synthesis of NPs using microorganisms and plant extracts is rather eco-friendly because it does not employ toxic reducing or stabilizing agents (Bhaduri et al., 2013;Kuppusamy et al., 2015). It is considered simple; is of low cost; is sustainable; can be performed under ambient temperature and pressure, without the use of external stabilizing agents; and is less toxic than the physical and chemical methods (Prasad, 2014;Vijayan et al., 2016;Zhang et al., 2016a). ...
The widespread and increase use of silver nanoparticles (AgNPs) as antimicrobial, antifungal, and antiviral results in an unknown release and accumulation in the aquatic environment and consequently in the trophic chain. In this chapter, different methods for AgNPs synthesis, use and applications, environmental concentration, potential mechanisms of toxicity, and the involved physicochemical factors are discussed. Also, the document displays an overview of toxic effects on key components of aquatic ecosystems: microalgae, plants, freshwater invertebrates, and fishes. Final remarks aim to contribute to a better understanding of how this emerging pollutant may pose a risk in the immediate-to long term to aquatic environments.
... There are various chemical and physical methods for the synthesis of metallic nanoparticles for example, one can use reduction of solutions, photochemical reactions in reverse micelles, electrochemical reduction, heat evaporation and radiation assisted methods, among others. These methods have usually been successful in the synthesis of nanomaterial in large quantities in short period of time, as well as for specific size and shape (Kuppusamy, et al., 2015). ...
There is a worldwide interest in silver nanoparticles (AgNPs) synthesize by various chemical reactions for use in applications. Silver nanoparticles have gained significant interest due to their unique optical, antimicrobial, electrical, physical properties and their possible application. However, it is necessary to develop environmental friendly methods for their syntheses. To avoid chemically toxicity, biosynthesis of metal silver nanoparticles is proposed as a cost-effective and environmental friendly alternative. This study aimed to find out whether Alagaw plant can potentially act as a reducing agent for the biosynthesis of silver nanoparticles and whether the concentration of the leaf extract can affect the absorbance spectrum, size and shape of the synthesized silver nanoparticles. The synthesized silver nanoparticles were characterized using the UV-vis spectroscopy for its absorbance spectrum and Transmission Electron Microscope Analysis for its morphology and size. The experimental method of research was used using three treatments and replicates of the different concentrations of Alagaw leaf extract: Treatment A (0.2 g/mL), Treatment B (0.4 g/mL) and Treatment C (0.6 g/mL) with 10 minutes and 60 minutes interval of observation under UV-vis spectrophotometer. Based on the findings of the study, Alagaw plant can potentially act as a good reducing agent for the biosynthesis of silver nanoparticles. The results recorded from UV-vis spectrophotometer support the biosynthesis and characterization of silver nanoparticles that as the concentration of the leaf extract increases it significantly affect the wavelength peaks and absorbance peaks of the synthesized silver nanoparticles. Using the high-resolution Transmission Electron Microscopy, the size of silver nanoparticles measured 50 nm – 100 nm having near-spherical in shape.
... The strong band at 3414.03 cm −1 attributes with O-H stretching vibration of the alcohol (Bibi et al. 2018). The peak at 1583.39 cm −1 is assigned with C=C stretching vibration of the cyclic alkene (Kuppusamy et al. 2015). The band at 1403.73 cm −1 may be assigned to strong stretching of the alkane (C-H) group (Sankar et al. 2014). ...
Nanotechnology tends to be a swiftly growing field of research that actively influences and inhibits the growth of bacteria/cancer. Noble metal nanoparticles (NPs) such as silver, copper, and gold have been used to damage bacterial and cancer growth over recent years; however, the toxicity of higher NPs concentrations remains a major issue. The copper oxide nanoparticles (CuONPs) were therefore fabricated using a simple green chemistry approach. Biofabricated CuONPs were characterized using UV-visible, FE-SEM with EDS, HR-TEM, FT-IR, XRD, Raman spectroscopy, and XPS analysis. Formations of CuONPs have been observed by UV-visible absorbance peak at 360.74 nm. The surface morphology of the CuONPs showed the spherical structure and size (~ 68 nm). The EDS spectrum of CuONPs has proved to be the key signals of copper (Cu) and oxygen (O) components. FT-IR analysis, to validate the important functional biomolecules (O–H, C=C, C–H, C–O) are responsible for reduction and stabilization of CuONPs. The monoclinic end-centered crystalline structures of CuONPs were confirmed with XRD planes. The electrochemical oxygen states of the CuONPs have been studied using spectroscopy of the Raman and X-ray photoelectron. After successful preparation, CuONPs examined their antibacterial, anticancer, and photocatalytic activities. Green-fabricated CuONPs were promising antibacterial candidate against human pathogenic gram-negative bacteria Escherichia coli, Vibrio cholerae, Salmonella typhimurium, Klebsiella pneumoniae, Aeromonas hydrophila, and Pseudomonas aeruginosa. CuONPs were demonstrated the excellent anticancer activity against A549 human lung adenocarcinoma cell line. Furthermore, CuONPs exhibited photocatalytic degradation of azo dyes such as eosin yellow (EY), rhodamine 123 (Rh 123), and methylene blue (MB). Biofabricated CuONPs may therefore be an important biomedical research for the aid of bacterial/cancer diseases and photocatalytic degradation of azo dyes.
... Plant extracts are a successful reduction agent for bio-AgNP synthesis [13][14][15][16][17] since they are rich in amide, phenols, carbonyl compounds and flavonoids [13,18,19]. A reduction agent is a chemical compound that reduces ions in the original solution. ...
Silver/silver oxide nanoparticles (AgNPs) is one of the most effective inorganic compounds that acts as an antibacterial agent against Escherichia coli (E. coli) bacteria. In this study, bio-silver or -silver oxide (bio-AgNPs) was synthesised from the seeds and peels of the Parkia speciosa (P. speciosa) plant, a green reducing agent. The seeds and peels were extracted separately via facile methods using a solution of silver nitrate (AgNO3). The seeds were soaked and peels mixed with the AgNO3 solution. The resulting bio-AgNPs were then incorporated into polysulfone (PSf) membranes at different weight percentages (0.1, 0.3, 0.5, and 1.0 wt%). The results showed that the PSf mixed matrix membrane (MMM) with 1.0 wt% of P. speciosa peel-derived bio-AgNPs (PP1.0) had the most optimum properties with a smaller crystallite size of 51.60 nm, an average diameter of finger-like cavities of 15.23 μm, the smallest mean pore size of 10.20 nm and the highest surface roughness of 39.90 nm. PP1.0 was also found to be highly hydrophilic since it had the lowest contact angle (63.30°) which was corroborated by the highest hydroxyl (−OH) peak (3454.21 cm⁻¹) seen during Fourier-transform infrared (FTIR) spectroscopy analysis. PP1.0 also had the highest water permeation flux (327.73 L m⁻² h⁻¹), lowest rejection rate (67.21%), lowest bio-AgNP leaching after water filtration (1.56 μg/L) and the formation of a 16.34 mm² antibacterial inhibition ring. This proved that PP1.0 had the potential to be applied as an antibacterial membrane for water separation.
Kohlrabi (Brassica oleracea var. gongylodes) is a vegetable of the cruciferous family (Brassicaceae). Based on the color of kohlrabi, it is classified as purple or pale green kohlrabi. Kohlrabi by-products include mainly peels, sprouts, leaves, and seeds, with several phytochemicals being reported from these by-products, such as anthocyanin, flavonoids, glucosinolates, indoles, phenolic acids, and phytosterols. Phytochemicals from kohlrabi by-products possess several biological activities, including anti-hyperalgesic, anti-inflammatory, anti-hyperglycemic, antibacterial, and antioxidant activities. Other health benefits from kohlrabi by-products include blood pressure lowering, cholesterol reduction, cancer-fighting, chemopreventive properties, and weight loss adjuvant. Furthermore, kohlrabi by-products have demonstrated promising applications in silver and gold nanoparticle synthesis, fermented vegetables, functional food formulation and packaging with potent antioxidant, antibacterial, and UV-blocking properties and extended shelf life and preservation properties. This chapter presents the latest research and development on the kohlrabi by-products regarding bioactive phytochemicals, biological activities, and their potential industrial applications.
Silver nanoparticles (AgNPs) are widely used in various industries, including textiles, electronics, and biomedical fields, due to their unique optical, electronic, and antimicrobial properties. However, the extensive use of AgNPs has raised concerns about their potential ecotoxicity and adverse effects on the environment. AgNPs can enter the environment through different pathways, such as wastewater, surface runoff, and soil application and can interact with living organisms through adsorption, ingestion, and accumulation, causing toxicity and harm. The small size, high surface area-to-volume ratio, and ability to generate reactive oxygen species (ROS) make AgNPs particularly toxic. Various bioremediation strategies, such as phytoremediation, have been proposed to mitigate the toxic effects of AgNPs and minimize their impact on the environment. Further research is needed to improve these strategies and ensure their safety and efficacy in different environmental settings.
Nanotechnology is the state-of-the-art technology providing new horizons of ideas and scope to unlimited possibilities in almost all genres of day-to-day life ranging from diagnostic, therapeutic, agricultural, chemical to microelectronics, sensors, etc. In this connection, one of the main concerns regarding the metal-oxide nanoparticles is their synthesis, application in a safe mood to protect the overall toxic impact on the food web. To resolve this concern, a greener and cleaner method of producing the nanoparticles is being looked upon as a favorable alternative more commonly referred to as green chemistry or green synthesis. The metal-oxide nanoparticles synthesized from biological sources have demonstrated fulfilling properties and shown antibacterial, antiviral, antifungal, drug delivery, catalytic activity, etc., response. In this chapter, the role of fruits and their wastes in the green synthesis of metal-oxide nanoparticles is discussed. This could efficiently reduce the cost and is safer for the environment thus allowing us to implore more on their benefits without impending much harm to the environment.KeywordsNanotechnologyFlavonoidsAnti-microbialPolyphenolsDrug deliveryBiosensor
Intracellular biosynthetic nanomaterials offer tremendous opportunities for chemical biomedical imaging. A wide range of biologically active tissues are available for biosynthesis, including cells, bacteria, plants, and viruses. Nanomaterials synthesized by intracellular biomineralization with outstanding biosafety and optical properties attract unique attention. Herein, an overview of biosynthetic tunable nanomaterials within active biological tissues for chemical biomedical imaging is presented. The synthetic mechanisms and nanostructures of biosynthetic nanomaterials are summarized from the perspective of different active organisms. The ability of biosynthesis is commonly used for green synthesis of metal nanoparticles compared to those synthesized by physical or chemical methods. The tunable characteristics of these nanoparticles make it possible to utilize them as fluorescence imaging, surface-enhanced Raman spectral mapping, nuclear magnetic resonance imaging, and other biomedical photonics tools. Importantly, current issues, insights, and future tendencies of development are presented based on current biosynthetic optical nanomaterials for chemical biomedical imaging. This paper provides the summary of biosynthetic optical nanomaterials and a critical assessment of potential biomedical imaging applications in this emerging field, laying the foundation for future studies.
Nanotechnology is the most active research area in modern materials science. Though there are numerous chemical and physical methods, green synthesis of nanomaterials is the most recent. In the present study, silver nanoparticles were synthesized by plant mediated green approach method using leaf extracts of medicinal fern Blechnum orientale Linn, provides necessary bioactive for reduction of silver ions to silver nanoparticles. Blechnum orientale was commonly known as ‘Centipede fern’, which is an important edible medicinal fern. Synthesized nanoparticles were elucidated using UV-visible spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), surface emission microscopy analysis (SEM) and its antioxidant activity was evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay as well as antimicrobial properties were studied against common food-borne pathogens. The highest absorbance of the produced silver nano particles (AgNPs) was 433 nm and the conversion of Ag+ ions to AgNPs was validated using Fourier transform infrared spectroscopy. FTIR result revealed the existence of O–H stretching and N–H amide group peaks. The as-synthesized AgNPs exhibited effective antibacterial action against food borne pathogens E. coli, Salmonella typhi, Pseudomonas aeruginosa and Shigella dysenteriae.
Data Science for COVID-19, Volume 2: Societal and Medical Perspectives presents the most current and leading-edge research into the applications of a variety of data science techniques for the detection, mitigation, treatment and elimination of the COVID-19 virus. At this point, Cognitive Data Science is the most powerful tool for researchers to fight COVID-19. Thanks to instant data-analysis and predictive techniques, including Artificial Intelligence, Machine Learning, Deep Learning, Data Mining, and computational modeling for processing large amounts of data, recognizing patterns, modeling new techniques, and improving both research and treatment outcomes is now possible.
Over the last few years, new nanoparticle preparation methods have emerged by replacing the usual reagents with plant extracts obtained in different conditions. An example of a natural plant extract is those of cruciferous vegetables, to obtain the new bio-nano-coatings. Given the composition of cruciferous extracts and large amounts of wastes produced all over the world, they can be successful substitutes to replace conventional coatings and extend the possibility of “smart coatings“. The present review aims to be a critical discussion regarding the application of cruciferous waste in nanotechnological applications. This review paper can be a starting report for different researchers who intend to use this sustainable approach “from green to nanotechnology” to transpose manufacturing from laboratory to industry. Applying this approach to obtain nanostructures with plant waste highlights the importance of minimizing and re-utilizing residues from primary and secondary processing via chemical and social intervention, in order to contribute to the sustainability needs of the planet and its inhabitants.
Metallic nanoparticles (MNPs) produced by green synthesis using plant extracts have attracted huge interest in the scientific community due to their excellent antibacterial, antifungal and antibiofilm activities. To evaluate these pharmacological properties, several methods or protocols have been successfully developed and implemented. Although these protocols were mostly inspired by the guidelines from national and international regulatory bodies, they suffer from a glaring absence of standardization of the experimental conditions. This situation leads to a lack of reproducibility and comparability of data from different study settings. To minimize these problems, guidelines for the antimicrobial and antibiofilm evaluation of MNPs should be developed by specialists in the field. Being aware of the immensity of the workload and the efforts required to achieve this, we set out to undertake a meticulous literature review of different experimental protocols and laboratory conditions used for the antimicrobial and antibiofilm evaluation of MNPs that could be used as a basis for future guidelines. This review also brings together all the discrepancies resulting from the different experimental designs and emphasizes their impact on the biological activities as well as their interpretation. Finally, the paper proposes a general overview that requires extensive experimental investigations to set the stage for the future development of effective antimicrobial MNPs using green synthesis.
Biosource-based green synthesized nanoparticles (NPs) have been showing extensive enthusiasm as a developing innovation to identify the carcinogenicity of NPs generally which are generally connected with regular science amalgamation systems. Studies on a green combination of metal/metal oxide NPs (MONPs) such as those containing silver, gold, palladium, platinum, iron, titanium, ceria, and magnetite, and also CuO, TiO2, Fe3O4, ZnO, and NiO NPs are produced using microscopic organisms with different natural materials, fungi, and plant extracts. Particularly plant materials are broadly utilized for the green synthesis of metal and MONPs, and the explanation behind this is the nearness of basic phytochemicals in the plant particularly extricates from the leaves. Plant material extracts contain terpenoids, flavonoids, ketones, aldehydes, amides, and an assortment of phytochemicals carboxylic acids, which assume a significant job in forming and improving the bioactivity of NPs. This chapter explains the prospective applications of phytochemical-derived metal/metal oxide nanostructures for environmental remediation applications. Finally, some perspectives on the future direction of the synthesis of metal/metal oxide nanostructures via green chemistry are provided. Flavonoids as phytochemicals are required for metal arrangement and MONPs and their improved bio-usefulness and environmental remediation. In addition, the consequences of bioprocess for the synthesis of metal as well as various types of MONPs are discussed. The challenges, limiting factors, and future direction of the plant-based synthesis of metal/ MONPs are also highlighted in this chapter.
The prevalence of coronavirus disease 2019 (COVID-19) exacerbated investor fears, uncertainties, and increased volatility in financial markets. The reaction to oil prices gradually absorbed the epidemic until March 08, but the market situation changed soon with a sharp drop in prices until April 17. This study aims to verify the impact of COVID-19 cases on crude oil prices and the Saudi economy. A simple linear regression estimate shows that new daily outbreaks have a marginally negative impact on crude oil prices in the short term. However, COVID-19 also has an indirect effect on the recent volatility in crude oil prices.
Solutions include proactive management, and we emphasize that special consideration must be given to the size of the supply to properly forecast oil prices. Volatility dominates in the short term. The relationship between the epidemic and oil prices reveals a root cause. Moreover, we investigate the interaction between the epidemic and oil prices, with the effective implementation of these solutions with the government's full support.
The ongoing coronavirus disease 2019 (COVID-19) pandemic is having devastating impacts across the globe. Among the implemented policies to reduce the spread of the disease is lockdown. This might have serious impact on farming activities and the livelihoods of millions of people whose daily means of sustenance is tied to agricultural activities. We undertook this study in West Africa, one of the most fragile and vulnerable regions to the epidemic. Our aim was to understand (1) farmers' perception of the impact of COVID-19 and lockdown policies on their farm or business revenue, (2) farmers' preparedness for COVID-19 lockdown on their farm or business revenue, and (3) the impact of effectiveness of COVID-19 lockdown on their farm or business revenue. We combined online questionnaire, physical contact and administration, and social media (Facebook and WhatsApp) to get responses from 303 farmers in Nigeria and Ghana. Our findings show that COVID-19 and lockdown policies negatively affected the farmers. The impact of COVID-19 and lockdown policies on respondents' farm or business revenue was independent of either age or gender of respondents and the effectiveness of lockdown in both the countries. The status of lockdown in respondent places (locked down versus not locked down) and the level of preparedness of farmers to handle the situation with the current COVID-19 crisis in their farms were also independent in both the countries. However, we found that the impact of COVID-19 and lockdown policies on farm or business revenue depends on the level of preparedness of farmers to handle the situation in each country. We further found that the impact of COVID-19 and lockdown policies on farm or business revenue was independent of the status of lockdown but rather depended on the preparedness for the current COVID-19 crisis and differently across countries. Our findings suggest that building capacities of farmers and supporting them in preparedness for such occurrence, as well as establishing and implementing public policies in this direction, can mitigate the impact of the pandemic on their activities.
According to the World Health Organization (WHO), viral infections continue to emerge and pose severe problems to public health. In mid-December 2019, coronavirus (coronavirus disease 2019 [COVID-19]) infection begun scattering from China. Globally, there are growing worries about community infections, in light of pandemic characterization for the outbreak by the WHO. Some studies have found that 1 out of 7 COVID-19 patients have acquired secondary bacterial infection, and half of the patients who have died had such infections. The challenge of antibiotic resistance could become an enormous force contributing to the rise in illness and death associated with COVID-19, as lower respiratory tract infections are among the leading causes of mortality in critically ill ventilated-patients with COVID-19.
The increasing prevalence of resistance to penicillin and other drugs among pneumococci has considerably complicated the treatment of acquired pneumonia. Resistance to other classes of antibiotics, traditionally used as alternatives in the treatment of pneumococcal infections, has also increased markedly in the recent years. Although the search for new antibiotics remains a top priority, the pipeline for new antibiotics is not encouraging, making it essential to search for other alternative solutions. Researching promising antimicrobial agents that are effective against COVID-19 as well as Streptococcus pneumoniae, which is a major cause of pneumonia, should be encouraged to reduce mortality related to COVID-19 infections. In this chapter, the relation between secondary infections and antibiotic resistance as contributors to high death rate among COVID-19 patients will be traced and highlighted. The possibility of using antimicrobial agents of plant origin, either independently or in combination with nanostructures, as preventive and/or treatment strategies for infections associated with COVID-19 will be reviewed.
In the present study silver nano-particles were synthesised by green synthesis method using fenugreek leaves extract, provides necessary bioactive for reduction of silver ions to silver nanoparticles. The sharp bands of silver nanoparticles were observed around 432 nm. Synthesis process was further optimized for pH, extraction temperature, Ag ion concentration, extract volume and extraction time on the basis of absorbance and average particles size respectively. FTIR analysis showed presence of corresponding peaks of O-H stretching and N-H amide groups. FESEM images revealed the structure and morphology of spherical AgNPs of average size 30 nm. The antibacterial activity of thus synthesized AgNPs was then tested against S. aureus, E. coli, P. aeruginosa and V. cholera and found synthesized AgNPs have higher inhibitory action against P. aeruginosa compared to other bacteria. The larger size of nano-particles is less active than smaller size of nano-particles due to small surface area.
Lichens are symbionts formed from the intimate union of fungi and algae and are enriched with distinct phytocompounds. Plants, bacteria, fungi and algae have been extensively explored for metallic nanoparticle synthesis but the use of lichens in the field of nanotechnology remains less explored. In the present study, Silver nanoparticles (Ag NPs) were synthesized using Heteroderimia leucomela lichen extract and characterized using different techniques. GC–MS analysis was performed to identify the phytocompounds supporting the synthesis of Ag NPs as capping and reducing agents. The antioxidant and antimicrobial activities were evaluated by in-vitro assays. Results showed that the synthesized Ag NPs had an average particle size of 20 ± 0.2 nm and were predominantly spherical in shape. The synthesized Ag NPs exhibited significant free radical scavenging activity for 2,2-diphenyl-1-picrylhydrzyl (DPPH) radicals with an IC50 value of 7.5 ± 0.1 μg/ml. The antibacterial activity of the synthesized Ag NPs against the test organisms were observed as follows: E. coli ≥ B. subtilis ≥ V. cholera ≥ S. pneumonia ≥ P. aeruginosa and the results of anticandida activity revealed that the candida strains were susceptible in the following order: C. albicans ≥ C. glabrata ≥ C. parapsilosis ≥ C. krusei ≥ C. tropicalis. Thus Ag NPs synthesized from high altitude lichen extract demonstrated that it has potent antioxidant and antimicrobial activities with greater importance to the field of nanomedicine.
Conventionally utilized physical and chemical routes for constructing nanoparticles are not eco-friendly. They are associated with many shortcomings like the requirement of specially designed equipment, templates, extremely high temperature, and pressure. Biosynthesis seems to be drawn unequivocal attention owing to its upsurge of applications in different fields like; energy, nutrition, pharmaceutical, and medicinal sciences. To harness the biological sources, the present review describes an environment-friendly route to generate biogenic nanoparticles from the natural plant extracts and the followed mechanisms for their synthesis, growth, and stabilization. The present review summarizes the recent trends involved in the photosynthesis of metallic nanoparticles and their effective use in controlling malaria, hepatitis, cancer, like various endemic diseases. Also, various characterization approaches, such as UV–visible spectrophotometry, Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy, are discussed here examine the properties of as-fabricated nanoparticles. Various plant parts like leaves, stems, barks, fruit, and flowers are rich in flavonoids, phenols, steroids, terpenoids, enzymes, and alkaloids, thereby playing an essential role in reducing metal ions that generate metallic nanoparticles. Herein, the uniqueness of phytofabricated nanoparticles along with their distinctive antibacterial, antioxidant, cytotoxic, and drug delivery properties are featured. Lastly, this work highlights the various challenges and future perspectives to further synthesize biogenic metal nanoparticles toward environmental and pharmaceutical advances in the coming years.
The present work aimed at synthesizing gold nanoparticles in a biological method employing fruit peel waste dumped in the environment. The peels of Garcinia mangostana (Mangostan), were collected from the nearby tourist spot during the season. The collected fruit peels were washed, dried, powder and extracted by using boiling water and acetone. The precipitated extract was dried and powdered for further use. The dried and powdered peel extract was added to the gold solution and boiled to 80 °C and the color change is observed. The color change indicates the completion of the synthesis of gold nanoparticles. The effect of pH, gold ion concentration, peel extract powder concentration, and the temperature was tested by varying the parameters. The biosynthesized nanoparticles were characterized using the UV–Vis spectrophotometer to identify the surface plasmon resonance peaks corresponding to gold nanoparticles. The bio-moieties responsible for the synthesis of gold nanoparticles were identified using the Fourier Transform Infra-Red Spectroscopy. The crystalline nature was detected by using an X-Ray Diffractometer. Atomic Force Microscope viewed the 3D surface image of the gold nanoparticle. The shape and morphology of the nanoparticle were identified by using a Field Emission Scanning Electron Microscope. The active compounds for gold nanoparticle synthesis were identified using Gas Chromatography-Mass Spectrometry. The gold nanoparticle was synthesized in various colors and used for dyeing cotton fabrics. The dyed cotton materials were exposed to various stress conditions to determine the color fastening.
Biological synthesis of nanomaterials aims at minimizing generated waste and implementing sustainable processes. Biosynthesis of nanomaterials using plant extracts is an innovative approach and an economical alternative for physical and chemical methods because the plant extract contains the secondary metabolites with high reducing potential, less toxic and can act as both reducing and stabilizing agent for synthesis of nanomaterials.
In this chapter, we have reviewed biosynthesis of nanomaterials using various medicinal plant extract and microorganisms with specific interest on Au, Ag, Cu, Zn and Ti nanoparticles. These metals were selected for the review as they have wider applications. Commonly available medicinal plants were utilized for the synthesis of nanoparticles, hence the issue of raw materials availability can be decreased. Different biological approaches for their synthesis, characterization of physicochemical properties of the products, and environmental applications are addressed. Factors influencing the nanoparticles synthesis are also discussed, hence optimizing the process parameters can be made easy. Among many different potential applications of the biosynthesized nanomaterials, we focused on their use for antimicrobial application and for environmental remediation. Additionally, background information regarding their mechanism of action, green synthesis, and future prospects have also been discussed.
In the last years, the growth of the world’s population has resulted in an increase in the demand for food. Vegetables and fruit are essential for human nutrition but, regrettably, half the fruit and vegetables produced worldwide are wasted. The food industry generates tons of by-products during processing, for instance, peels, seeds and stems, which still possess bioactive compounds that can be of interest for other applications. The Brassicaceae species includes some of the most consumed vegetables worldwide known for their antioxidant activity associated with the presence of phenolic compounds. In this study, the stems of Brassica oleracea var. acephala cv. Galega (hereafter BG) were employed to prepare an aqueous extract. Then, its antioxidant potential was evaluated by means of the in vitro analysis of its ability to scavenge the free radical 1,1-diphenyl-2-picryl-hydrazyl (DPPH), the quantification of the total phenolic content and the analysis of the reducing power. Furthermore, the stem aqueous extract was employed to produce gold nanoparticles (AuNPs), acting as a reducing and stabilizing agent. AuNPs were characterized by UV–Visible and Fourier transform infrared spectroscopy. The size and shape of the nanoparticles was analyzed by the acquisition of transmission electron microscopy images, confirming the formation of spherical AuNPs with mean diameters of 25.08 ± 3.73 nm. Finally, three antioxidant assays were performed in the extract after the synthesis of AuNPs. The synthesis of AuNPs employing BG stem extract was revealed to be a good alternative for the revalorization of Brassica by-products.Graphical abstract
Green synthesis is one of the most valuable and emerging methods for the synthesis of nanoparticles (NPs) nowadays, presenting imperative biological benefits, reduced process time, cost-effectiveness, and environmental benefits, as an alternative to physical and chemical processes. Silver, a noble metal, possess unique properties and potential applications in medicine, requiring the search for novel and suitable tools for its production due to the growing demand. The exploration of plants diversity can be used towards rapid and single-step preparatory methods for various NPs, maintaining the green principle over conventional ones, an important aspect for medical applications. Plants contain bio-organics components, which usually play multiple roles as reducing, capping as well as stabilizing agents for metal compounds into silver nanoparticles (AgNPs). The stability of these NPs is governed by certain parameters, which influence stability and bioavailability. In this perspective, this review aims to provide a comprehensive view to understand the possible induced mechanism, current scenario and future prospects for the bio-inspired synthesis of AgNPs.
Synthesis of metal nanoparticles using plant extracts is one of the most simple, convenient, economical, and environmentally friendly methods that mitigate the involvement of toxic chemicals. Hence, in recent years, several eco-friendly processes for the rapid synthesis of silver nanoparticles have been reported using aqueous extracts of plant parts such as the leaf, bark, roots, etc. This review summarizes and elaborates the new findings in this research domain of the green synthesis of silver nanoparticles (AgNPs) using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015. While highlighting the recently used different plants for the synthesis of highly efficient antimicrobial green AgNPs, we aim to provide a systematic in-depth discussion on the possible influence of the phytochemicals and their concentrations in the plants extracts, extraction solvent, and extraction temperature, as well as reaction temperature, pH, reaction time, and concentration of precursor on the size, shape and stability of the produced AgNPs. Exhaustive details of the plausible mechanism of the interaction of AgNPs with the cell wall of microbes, leading to cell death, and high antimicrobial activities have also been elaborated. The shape and size-dependent antimicrobial activities of the biogenic AgNPs and the enhanced antimicrobial activities by synergetic interaction of AgNPs with known commercial antibiotic drugs have also been comprehensively detailed.
Antimicrobial drug resistance continued to be the major threat for the basic researchers, clinicians and biotech industries. Prescription of higher than the recommended drug concentrations may lead to a series of adverse cyto- and genotoxic effects in hosts. Therefore, discovery and application of novel antimicrobial agents are in high demand to overcome the acquired multidrug resistance in pathogens. Recent advancements in nanotechnology showed tremendous promise in developing nanoparticles (NPs) of superior antimicrobial efficacy, yet fortified with improved shelf-life, water solubility and reduced systemic toxicity in hosts. However, the physical and chemical modes of NP-synthesis require the use of potentially hazardous chemicals incumbent on high synthesis cost. Recently, green syntheses of NPs are gaining huge attention both in industries and academia, owing to the use of biologically derived components and cost effectiveness. The use of biomaterials such as plant extracts or microorganisms such as bacteria, yeast or fungi are being increasingly used in the synthesis of metallic and non-metallic NPs. The present review summarizes the synthesis strategies and antimicrobial mechanism of actions of the green NPs (GrNPs). We also discuss shortcomings of the existing set up and scope of future optimization in an anticipation that GrNPs will emerge as the next generation effective and economic antimicrobial agents.
Production of environmentally amenable silver nanoparticles (AgNPs) has garnered the interest of the scientific community owing to their broad application primarily in the field of optronics, sensing and extensively in pharmaceuticals as promising antioxidant, antimicrobial and anticancer agents. The current study emphases on production of ecofriendly silver nanoparticles from Brassica oleracea (BO) and investigated their antibacterial, anticancer and antioxidant activity. The characteristics of synthesized BO-AgNPs were studied by ultraviolet–visible spectroscopy, particle size analysis, electro kinetic/zeta potential analysis, and Transmission electron microscope (TEM). A distinctive absorption maximum at 400 nm confirmed the formation of BO-AgNPs and data on TEM analysis have shown that the synthesized nanoparticles were predominantly spherical in shape. The BO-AgNPs obtained were assessed for antibacterial, antioxidant, and cytotoxic ability in MCF-7 cells. The antibacterial activity expressed was maximum against Staphylococcus epidermidis (Gram positive) and Pseudomonas aeruginosa (Gram negative) with DIZ of 14.33 ± 0.57 and 12.0 ± 0.20 mm respectively . Furthermore, the ability of the synthesized green nanoparticles to scavenge free radicals revealed a strong antioxidant activity. The cytotoxicity increased proportionately with increasing concentration of the green synthesized BO-AgNPs with maximum effect at 100 μg/ml and IC50 of 55 μg/ml. In conclusion, the data obtained in the study is reflective of the role of BO-AgNPs as potential and promising antimicrobial agent against bacterial infections and potential anticancer agent in cancer therapy.
The research was focused on the synthesis of silver nanoparticles (AgNPs) using extracts from the “hairy” root cultures of Artemisia tilesii Ledeb. and Artemisia annua L. The effect of operational parameters such as type of solvent, temperature of extraction, flavonoids concentration, and reducing power of the wormwood “hairy” root extracts on the particle size and yield of the resultant nanoparticles is reported for the first time. From the studied solvents, a water–ethanol mixture with a concentration of 70 vol%
was found to be the best for the extraction of flavonoids from all “hairy” root cultures. The total flavonoid contents in A. annua and A. tilesii “hairy” root extracts were up to 80.0 � 0.9 and 108 � 4.4 mg
RuE per g DW, respectively. Identification of flavonoids was confirmed by UPLC-ESI-UHR-Qq-TOF-MS analysis. Luteolin-7-b-D-glucopyranosid, isorhamnetin 3-O-glucoside, baicalein-7-O-glucuronide, apigenin-7-O-glucoside, quercetin, sitosterol, caffeoylquinic, galic, chlorogenic and caffeic acids were founded in the extracts. These extracts demonstrated the high reducing activities. Spherical, oval and triangular nanoparticles with effective sizes of 5–100 nm were observed. The TEM data revealed great differences in the shapes of NPs, obtained from the extracts from different root clones. The clustered and irregular NPs were found in the case of using ethanol extracts, mostly aggregated and having the
size of 10–50 nm. The sizes of AgNPs decreased to 10–30 nm in the case of using aqueous extracts
obtained at 80 C. Biosynthesized AgNPs showed surface plasmon resonance in the range of 400–450 nm. The antimicrobial activity of the as-produced AgNPs was studied by disc diffusion method on
Gram-positive (Staphylococcus aureus ATCC 25923 (F-49)), Gram-negative (Pseudomonas aeruginosa ATCC 27853 (F-51), Escherichia coli ATCC 25922 (F-50)) and Candida albicans ATCC 88-653 strains. It
was found that the nanoparticles in some cases possessed the greater ability to inhibit microorganism growth compared to 1 mM AgNO3 solution. The colloidal solutions of the obtained AgNPs were stable in the dark for 12 months at room temperature. Thus, the A. annua and A. tilesii “hairy” root extracts can be used for obtaining of bioactive AgNPs.
Green synthesis of nanoparticles, one of the most important areas of nanotechnology, allows the synthesis of variable sizes and shapes nanoparticles through "green" routs. The objective of this study was to synthesize gold and silver nanoparticles using chlorophyll extracted and purified from Spinacia oleracea. Analytical techniques (UV-Vis spectroscopy, thin layer chromatography - TLC, energy-dispersive X-ray fluorescence - EDXRF, scanning electron microscope - SEM) have been used to characterize the obtained materials. The absorption peaks at ~550 and ~452 nm confirmed the formation of gold and silver nanoparticles. The SEM measurements reveal that the dimension of the particles is in the range 50-100 nm for gold and from 100-300 nm to few micrometers for silver clusters.
Aim: To determine the therapeutic effect of thy- mosin β4 (Tβ4) for treatment of ischemic limb disease in a mouse model. Methods: A mouse model of hindlimb ischemia was created by permanent ligation of femoral arteries and internal iliac artery. Tβ4 was dissolved in sterile saline and intramuscularly injected into the centre and periphery of ligation area in the treatment group (n = 10) starting from the surgery day until 4 weeks after surgery, while control animals received saline injection only (n = 9). All animals were sacrificed at 6 weeks after surgery and used for immunohistochemistry studies. Results: Tβ4 stimulated angiogenesis was evidenced by increased vascular density based on CD31 immunostaining, which was sig- nifycantly increased in Tβ4 group (562.5 ± 78.4/mm2) as compared with control group (371.1 ± 125.7/mm2; p 0.05) groups. Tβ4 increased Pax3/7+ skeletal muscle progenitor cell density. Pax3/7+ cell density of Tβ4 group (13.7% ± 2%) was significantly higher than that of the control group (4.3% ± 1.6%, p < 0.05). However, the numbers of central nuclei fiber and central nuclei per fiber were insignificantly increased in Tβ4 group as compared to control group. The numbers of central nuclei fiber were 8.9 ± 2.1 and 9.5 ± 1.6, and the central nuclei per fiber were 0.25 ± 0.07 and 0.48 ± 0.09 for control and Tβ4 groups, respectively. Conclusions: This preliminary study suggests that localized delivery of Tβ4 increased angiogenesis and skeletal muscle progenitor cell density in ischemic skeletal muscle, but failed to promote skeletal muscle regeneration.
Background
It is imperative to eliminate bacteria present in water in order to avoid problems in healthy. Escherichia coli and Salmonella typhi bacteria are two common pollutants and they are developing resistance to some of the most used bactericide. Therefore new biocide materials are being tested. Thus, gold nanoparticles are proposed to inhibit the growth of these two microorganisms.
Results
Gold nanoparticles were supported onto clinoptilolite, mordenite and faujasite zeolites. Content of gold in materials varied between 2.3 and 2.8 wt%. The size, dispersion and roughness of gold nanoparticles were highly dependent of the zeolite support. The faujasite support was the support where the 5 nm nanoparticles were highly dispersed. The efficiency of gold-zeolites as bactericides of Escherichia coli and Salmonella typhi was determined by the zeolite support.
Conclusions
Gold nanoparticles dispersed on zeolites eliminate Escherichia coli and Salmonella typhi at short times. The biocidal properties of gold nanoparticles are influenced by the type of support which, indeed, drives key parameters as the size and roughness of nanoparticles. The more actives materials were pointed out Au-faujasite. These materials contained particles sized 5 nm at surface and eliminate 90–95% of Escherichia coli and Salmonella typhi colonies.
The development of rapid and ecofriendly processes for the synthesis of silver (Ag) and gold (Au) nanoparticles is of great
importance in the field of nanotechnology. In this study, the extracellular production of Ag and Au nanoparticles was carried
out from the leaves of the plants, Tridax procumbens L. (Coat buttons), Jatropa curcas L. (Barbados nut), Calotropis gigantea L. (Calotropis), Solanum melongena L. (Eggplant), Datura metel L. (Datura), Carica papaya L. (Papaya) and Citrus aurantium L. (Bitter orange) by the sunlight exposure method. Qualitative comparisons of the synthesized nanoparticles between the
plants were measured. Among these T. procumbens, J. curcas and C. gigantea plants synthesized <20 nm sized and spherical-shaped Ag particles, whereas C. papaya, D. metel and S. melongena produced <20 nm sized monodispersed Au particles. The amount of nanoparticles synthesized and its qualitative characterization
was done by UV–vis spectroscopy and transmission electron microscopy (TEM), respectively. X-ray diffraction (XRD) and X-ray
photoelectron spectroscopy (XPS) were used for structural confirmation. Further analysis carried out by fourier transform
infrared spectroscopy (FTIR), provided evidence for the presence of amino groups, which increased the stability of the synthesized
nanoparticles.
KeywordsSilver nanoparticles-Gold nanoparticles-Biogenic synthesis of nanoparticles-Sunlight-Nanobiotechnology
Diseases such as tuberculosis (TB) have always had a large impact on human health. Bacillus Calmette-Guérin (BCG) is used as a surrogate for TB during the development of anti-TB drugs. Nanoparticles (NPs) have attracted great interest in drug development. The purpose of this study was to examine the potential of NPs as anti-TB compounds by studying the interacting mechanisms between NPs and bacteria.
We investigated effects of gold and silver NPs on BCG and Escherichia coli. Experimentally, particle size and shape were characterized using transmission electron microscopy (TEM). Different concentrations of NPs were applied in bacterial culture. The growth of E. coli was monitored through colony forming units (CFU). The mechanism of interaction between NPs and bacteria was analyzed through bacterial thin sections followed by TEM and scanning electron microscopy. Antibacterial effects on BCG were observed by recording fluorescent protein expression levels.
The results suggest NPs have potential applications as anti-TB compounds. The antibacterial effects and mechanism of action for NPs were dependent upon composition and surface modifications.
Nanotechnology is expected to open new avenues to fight and prevent disease using atomic scale tailoring of materials. Among the most promising nanomaterials with antibacterial properties are metallic nanoparticles, which exhibit increased chemical activity due to their large surface to volume ratios and crystallographic surface structure. The study of bactericidal nanomaterials is particularly timely considering the recent increase of new resistant strains of bacteria to the most potent antibiotics. This has promoted research in the well known activity of silver ions and silver-based compounds, including silver nanoparticles. The present work studies the effect of silver nanoparticles in the range of 1-100 nm on Gram-negative bacteria using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM). Our results indicate that the bactericidal properties of the nanoparticles are size dependent, since the only nanoparticles that present a direct interaction with the bacteria preferentially have a diameter of approximately 1-10 nm.
In this paper, we demonstrate the synthesis of monodispersed silver nanoparticles (NPs) of controlled size (20.5 +/- 3.3 nm) in aqueous phase from a silver hydroxide precursor with sodium acrylate as dual reducing-capping agent. We then coat these NPs in a layer of gold with controllable thickness through a reduction-deposition process. The materials are characterized using several techniques including high-resolution transmission electron microscopy, ultraviolet-visible spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The results show that we were able to synthesize not only monodispersed Ag NPs but also core-shell Ag-Au NPs with a discrete structure, which is significant because of the challenges associated with the creation of such materials, namely the propensity of metallic Ag to be oxidized by the presence of ionic Au. The NPs are of interest for use in a wide range of potential applications, including biomedical diagnostics and biomolecular detection as well as many others.
A study of the use of free silver ions as an antibacterial and antifungal agent administered to
infected local wounds has been conducted over the past two decades. A variety of iontophoretic
techniques has been employed utilizing either pure silver wires or several types of silvered nylon
fabrics as anodes in a direct current electrical circuit. A new type of silver nylon has recently been
evaluated for the same use without iontophoretic current. In vitro studies of both techniques have
demonstrated an effective, broad spectrum antibiotic effect including most silver-resistant strains.
Over 100 cases of recalcitrant osteomyelitis have been treated with an overall success rate of
approximately 65% and no evidence of argyria.
Following the recent launch of Apple’s fifth generation of the iPhone product line, this study specifically looks at the feedback from consumers who experience grief as a result of a let-down in anticipation. This study randomly extracts some useful consumer comments from online forums, reviews and Tumblr illustrations. From these findings, this study provides some comments on its possible implications for market leaders of establish brand names.
Current prospect of nanobiotechnology involves in the greener synthesis of nanostructured materials particularly noble metal nanoparticles for various biomedical applications. In this study, biologically (Podophyllum hexandrum L.) synthesized crystalline gold nanoparticles (AuNPs) with the size range between 5 and 35 nm were screened for its anticancereous potential against human cervical carcinoma cells (HeLa). Stoichiometric proportion of the reaction mixture and conditions were optimized to attain stable nanoparticles with narrow size range. Different high throughput techniques like transmission electron microscope (TEM), X-ray diffraction (XRD) and UV–vis spectroscopy were adopted for the physio-chemical characterization of AuNPs. Additionally, Fourier transform infrared spectroscopy (FTIR) study revealed that the water soluble fractions present in the plant extract solely influences the reduction of AuNPs. Sublimely, synthesized AuNPs exhibits an effective in vitro anticancer activity against HeLa cells via induction of cell cycle arrest and DNA damage. Furthermore, it was evidenced that AuNPs treated cells are undergone apoptosis through the activation of caspase cascade which subsequently leads to mitochondrial dysfunction. Thereby, this study proves that biogenic colloidal AuNPs can be developed as a promising drug candidature for human cervical cancer therapy.
This paper reports a facile and rapid biosynthesis of silver and gold nanoparticles from Chenopodium album, an obnoxious weed. The aqueous leaf extract of the herb was used as mild reducing agent for silver and gold nanoparticles (SNPs and GNPs) synthesis from their salt solutions in single-pot process. Quasi-spherical shapes were observed for biosynthesized SNPs and GNPs within range of 10–30nm, respectively. The UV–VIS spectra gave surface plasmon resonance (SPR) for SNPs and GNPs at 460 and 540nm, respectively. Influence of leaf extract quantities, metal concentrations, contact time, reaction temperature and pH were evaluated to find their effects on NPs synthesis. The produced nanocrystals of silver and gold were analyzed with transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) and fourier transform infrared spectroscopy (FTIR). The stability of NPs was evaluated at different pH with zeta potentiometer without adding any stabilizing agents.
Now-a-days synthesis and characterization of silver nanoparticles (AgNPs) through biological entity is quite interesting to employ AgNPs for various biomedical applications in general and treatment of cancer in particular. This paper presents the green synthesis of AgNPs using leaf extract of Podophyllum hexandrum Royle and optimized with various parameters such as pH, temperature, reaction time, volume of extract and metal ion concentration for synthesis of AgNPs. TEM, XRD and FTIR were adopted for characterization. The synthesized nanoparticles were found to be spherical shaped with average size of 14nm. Effects of AgNPs were analyzed against human cervical carcinoma cells by MTT Assay, quantification of ROS, RT-PCR and western blotting techniques. The overall result indicates that AgNPs can selectively inhibit the cellular mechanism of HeLa by DNA damage and caspase mediated cell death. This biological procedure for synthesis of AgNPs and selective inhibition of cancerous cells gives an alternative avenue to treat human cancer effectively.
Now-a-days synthesis and characterization of silver nanoparticles (AgNPs) through biological entity is quite interesting to employ AgNPs for various biomedical applications in general and treatment of cancer in particular. This paper presents the green synthesis of AgNPs using leaf extract of Podophyllum hexan-drum Royle and optimized with various parameters such as pH, temperature, reaction time, volume of extract and metal ion concentration for synthesis of AgNPs. TEM, XRD and FTIR were adopted for characterization. The synthesized nanoparticles were found to be spherical shaped with average size of 14 nm. Effects of AgNPs were analyzed against human cervical carcinoma cells by MTT Assay, quantification of ROS, RT-PCR and western blotting techniques. The overall result indicates that AgNPs can selectively inhibit the cellular mechanism of HeLa by DNA damage and caspase mediated cell death. This biological procedure for synthesis of AgNPs and selective inhibition of cancerous cells gives an alternative avenue to treat human cancer effectively.
Aqueous extract of Ocimum sanctum leaf is used as reducing agent for the environmentally friendly synthesis of gold and silver nanoparticles. The nanoparticles were characterized using UV–vis, transmission electron microscopy (TEM), X-ray diffraction (XRD) and FTIR analysis. These methods allow the synthesis of hexagonal gold nanoparticles having size ∼30 nm showing two surface plasmon resonance (SPR) bands by changing the relative concentration of HAuCl4 and the extract. Broadening of SPR is observed at larger quantities of the extract possibly due to biosorption of gold ions. Silver nanoparticles with size in the range 10–20 nm having symmetric SPR band centered around 409 nm are obtained for the colloid synthesized at room temperature at a pH of 8. Crystallinity of the nanoparticles is confirmed from the XRD pattern. Biomolecules responsible for capping are different in gold and silver nanoparticles as evidenced by the FTIR spectra.Research highlights► Green method is followed for the synthesis of gold and silver nanoparticles. ► Tulsi leaf extract is used to reduce gold and silver ions. ► Hexagonal shaped gold nanoparticles are obtained. ► Broadening of SPR is observed possibly due to biosorption.
In this present work, we developed a green method for the synthesis of stable Au NPs that does not require any of the conventional stabilizing ligands. This synthesis can be performed in minutes rather than hours, under very mild conditions using aqueous leaf extract of Callistemon viminalis. Gold nanotriangles so prepared were well characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), quasi elastic light scattering (QELS), UV–visible spectroscopy techniques etc. Powder X-ray diffraction plot revealed the presence of only gold in zero oxidation state.
The surface plasmon response of metal nanoparticles is studied for different shapes and physical environments. For polyhedral nanoparticles, the surface plasmon resonances are studied as a function of the number of faces and vertices. The modification of these surface plasmons by different surrounding media and the presence of a substrate or other nanoparticles is also discussed. We found that polyhedral nanoparticles composed with less faces show more surface plasmon resonances, and as the nanoparticle becomes more symmetric, the main surface plasmon resonance is blue-shifted. It is also found that the corners induce more surface plasmons in a wider energy range. In the presence of a substrate, multipolar plasmon resonances are induced, and as the nanoparticle approaches the substrate, such resonances are red-shifted. The interaction among nanoparticles also induces multipolar resonances, but they can be red or blue-shifted depending on the polarization of the external field.
In the recent decades, increased development of green synthesis of nanoparticles is inevitable because of its incredible applications in all fields of science. There were numerous work have been produced based on the plant and its extract mediated synthesis of nanoparticles, in this present study to explore that the novel approaches for the biosynthesis of silver nanoparticles using plant fruit bodies. The plant, Tribulus terrestris L. fruit bodies are used in this study, where the dried fruit body extract was mixed with silver nitrate in order to synthesis of silver nanoparticles. The active phytochemicals present in the plant were responsible for the quick reduction of silver ion (Ag(+)) to metallic silver nanoparticles (Ag(0)). The reduced silver nanoparticles were characterized by Transmission Electron Microscope (TEM), Atomic Force Microscope (AFM), XRD, FTIR, UV-vis spectroscopy. The spherical shaped silver nanoparticles were observed and it was found to be 16-28 nm range of sizes. The diffraction pattern also confirmed that the higher percentage of silver with fine particles size. The antibacterial property of synthesized nanoparticles was observed by Kirby-Bauer method with clinically isolated multi-drug resistant bacteria such as Streptococcus pyogens, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus aureus. The plant materials mediated synthesis of silver nanoparticles have comparatively rapid and less expensive and wide application to antibacterial therapy in modern medicine.
Glucosinolates are secondary plant metabolites found mainly in the order Capparales. Tissue disruption allows rapid enzymatic degradation of glucosinolates by specific thioglucosidases, denoted myrosinases. Within the last few years, significant progresses in our understanding of glucosinolate biosynthesis and degradation have been achieved. In particular, the Arabidopsis thaliana genome-sequencing project has accelerated the identification and characterization of genes involved in the glucosinolate metabolism. More evidence has accumulated for the hypothesis that the glucosinolate-myrosinase system has evolved from the prevalent system of cyanogenic glucosides and corresponding O-β-glucosidases. Glucosinolates have been shown to be taken up by a specific carrier system and transported by phloem. The de novo biosynthesis, degradation and transport of glucosinolates may constitute a delicately regulated dynamic diagram, through which various physiological functions are fulfilled. There is a rising interest in controlling the level of glucosinolates in crops to improve pest resistance and nutritional value. Genes identified in Arabidopsis thaliana will provide important tools to initiate molecular strategies to modulate the quantity and quality of glucosinolates in a tissue-specific manner in closely related Brassica crops. This review summarizes current knowledge on glucosinolate biosynthesis, degradation and mobilization, and provides a comprehensive discussion and update on the regulation, physiological functions and genetic engineering of glucosinolate metabolism and transport.
Extracellular biological synthesis of gold nanoparticles was achieved by a simple biological procedure using coriander extract as the reducing agent. The aqueous gold ions when exposed to coriander leaf extract are reduced and resulted in the biosynthesis of gold nanoparticles in the size range from 6.75–57.91 nm. The gold nanoparticles were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), fourier transform infra-red spectroscopy (FT-IR) and transmission electron microscopy (TEM). This eco-friendly approach for the synthesis of nanoparticles is simple, amenable for large scale commercial production and technical applications.
Biosynthesis of nanoparticles is under exploration is due to wide biomedical applications and research interest in nanotechnology. Bioreduction of silver nitrate (AgNO(3)) and chloroauric acid (HAuCl(4)) for the synthesis of silver and gold nanoparticles respectively with the plant extract, Mentha piperita (Lamiaceae). The plant extract is mixed with AgNO(3) and HAuCl(2), incubated and studied synthesis of nanoparticles using UV-Vis spectroscopy. The nanoparticles were characterized by FTIR, SEM equipped with EDS. The silver nanoparticles synthesized were generally found to be spherical in shape with 90 nm, whereas the synthesized gold nanoparticles were found to be 150 nm. The results showed that the leaf extract of menthol is very good bioreductant for the synthesis of silver and gold nanoparticles and synthesized nanoparticles active against clinically isolated human pathogens, Staphylococcus aureus and Escherichia coli.
Silver nanoparticles are of interest to be used as antimicrobial agents in wound dressings and coatings in medical devices, but potential adverse effects have been reported in the literature. The most pronounced effect of silver nanoparticles and the role of particle size in determining these effects, also in comparison to silver ions, are largely unknown. Effects of silver nanoparticles of different sizes (20, 80, 113 nm) were compared in in vitro assays for cytotoxicity, inflammation, genotoxicity and developmental toxicity. Silver nanoparticles induced effects in all endpoints studied, but effects on cellular metabolic activity and membrane damage were most pronounced. In all toxicity endpoints studied, silver nanoparticles of 20 nm were more toxic than the larger nanoparticles. In L929 fibroblasts, but not in RAW 264.7 macrophages, 20 nm silver nanoparticles were more cytotoxic than silver ions. Collectively, these results indicate that effects of silver nanoparticles on different toxic endpoints may be the consequence of their ability to inflict cell damage. In addition, the potency of silver in the form of nanoparticles to induce cell damage compared to silver ions is cell type and size-dependent.
Hundreds of consumer products are on the market that contain metallic silver nanoparticles. Given the potential toxicity of
silver, these engineered nanoparticles are currently under intense scrutiny by environmental and occupational scientists (1) and regulators (2). The reason for this interest is that the physical and chemical properties of particles in the nanorange (from about 1 to
100 nm) can be different from larger particles or dissolved compounds, and it is not yet clear whether these different properties
also require a new and more rigorous human and environmental risk assessment compared with their larger counterparts. In a
recent article, Kim et al. (3) reported the discovery and identification of silver sulfide (Ag2S) nanoparticles in sewage sludge. This finding provides some insight into the fate of silver that had been introduced in
various forms into the environment.
The antifungal activity of the silver nanoparticles (NPs) prepared by the modified Tollens process was evaluated for pathogenic Candida spp. by means of the determination of the minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and the time-dependency of yeasts growth inhibition. Simultaneously the cytotoxicity of the silver NPs to human fibroblasts was determined. The silver NPs exhibited inhibitory effect against the tested yeasts at the concentration as low as 0.21 mg/L of Ag. The inhibitory effect of silver NPs was enhanced through their stabilization and the lowest MIC equal to 0.05 mg/L was determined for silver NPs stabilized by sodium dodecyl sulfate against Candida albicans II. The obtained MICs of the silver NPs and especially of the stabilized silver NPs were comparable and in some cases even better than MICs of the conventional antifungal agents determined by E-test. The silver NPs effectively inhibited the growth of the tested yeasts at the concentrations below their cytotoxic limit against the tested human fibroblasts determined at a concentration equal to 30 mg/L of Ag. In contrast, ionic silver inhibited the growth of the tested yeasts at the concentrations comparable to the cytotoxic level (approx. 1mg/L) of ionic silver against the tested human fibroblasts.
The rapid advancement of nanotechnology has created a vast array of engineered nanomaterials (ENMs) which have unique physical (size, shape, crystallinity, surface charge) and chemical (surface coating, elemental composition and solubility) attributes. These physicochemical properties of ENMs can produce chemical conditions to induce a pro-oxidant environment in the cells, causing an imbalanced cellular energy system dependent on redox potential and thereby leading to adverse biological consequences, ranging from the initiation of inflammatory pathways through to cell death. The present study was designed to evaluate size-dependent cellular interactions of known biologically active silver nanoparticles (NPs, Ag-15 nm, Ag-30 nm, and Ag-55 nm). Alveolar macrophages provide the first defense and were studied for their potential role in initiating oxidative stress. Cell exposure produced morphologically abnormal sizes and adherence characteristics with significant NP uptake at high doses after 24 h. Toxicity evaluations using mitochondrial and cell membrane viability along with reactive oxygen species (ROS) were performed. After 24 h of exposure, viability metrics significantly decreased with increasing dose (10-75 microg/mL) of Ag-15 nm and Ag-30 nm NPs. A more than 10-fold increase of ROS levels in cells exposed to 50 microg/mL Ag-15 nm suggests that the cytotoxicity of Ag-15 nm is likely to be mediated through oxidative stress. In addition, activation of the release of traditional inflammatory mediators were examined by measuring levels of cytokines/chemokines, including tumor necrosis factor (TNF-alpha), macrophage inhibitory protein (MIP-2), and interleukin-6 (IL-6), released into the culture media. After 24 h of exposure to Ag-15 nm nanoparticles, a significant inflammatory response was observed by the release of TNF-alpha, MIP-2, and IL-1beta. However, there was no detectable level of IL-6 upon exposure to silver nanoparticles. In summary, a size-dependent toxicity was produced by silver nanoparticles, and one predominant mechanism of toxicity was found to be largely mediated through oxidative stress.
Nanomedicine involves measurement and therapy at the level of 1-100 nm. Although the science is still in its infancy, it has major potential applications in diabetes. These include solving needs such as non-invasive glucose monitoring using implanted nanosensors, with key techniques being fluorescence resonance energy transfer (FRET) and fluorescence lifetime sensing, as well as new nano-encapsulation technologies for sensors such as layer-by-layer (LBL) films. The latter might also achieve better insulin delivery in diabetes by both improved islet encapsulation and oral insulin formulations. An 'artificial nanopancreas' could be an alternative closed-loop insulin delivery system. Other applications of nanomedicine include targeted molecular imaging in vivo (e.g. tissue complications) using quantum dots (QDs) or gold nanoparticles, and single-molecule detection for the study of molecular diversity in diabetes pathology.
One mechanism of silver resistance in microorganisms is accumulation of the metal ions in the cell. Here, we report on the phenomenon of biosynthesis of silver-based single crystals with well-defined compositions and shapes, such as equilateral triangles and hexagons, in Pseudomonas stutzeri AG259. The crystals were up to 200 nm in size and were often located at the cell poles. Transmission electron microscopy, quantitative energy-dispersive x-ray analysis, and electron diffraction established that the crystals comprise at least three different types, found both in whole cells and thin sections. These Ag-containing crystals are embedded in the organic matrix of the bacteria. Their possible potential as organic-metal composites in thin film and surface coating technology is discussed.
We report on the use of Neem (Azadirachta indica) leaf broth in the extracellular synthesis of pure metallic silver and gold nanoparticles and bimetallic Au/Ag nanoparticles. On treatment of aqueous solutions of silver nitrate and chloroauric acid with Neem leaf extract, the rapid formation of stable silver and gold nanoparticles at high concentrations is observed to occur. The silver and gold nanoparticles are polydisperse, with a large percentage of gold particles exhibiting an interesting flat, platelike morphology. Competitive reduction of Au3+ and Ag+ ions present simultaneously in solution during exposure to Neem leaf extract leads to the synthesis of bimetallic Au core-Ag shell nanoparticles in solution. Transmission electron microscopy revealed that the silver nanoparticles are adsorbed onto the gold nanoparticles, forming a core-shell structure. The rates of reduction of the metal ions by Neem leaf extract are much faster than those observed by us in our earlier studies using microorganisms such as fungi, highlighting the possibility that nanoparticle biological synthesis methodologies will achieve rates of synthesis comparable to those of chemical methods.
Can weakly active phytochemicals be combined synergistically to produce new antibacterial treatments?
Performance standards for antimicrobial susceptibility testing Blood Safety and Clinical Technology Guidelines on Standard Operating Procedures for Microbiology. Eight Informational Supplement
- Antimicrobial Susceptibility Testing
NCCLS and Antimicrobial Susceptibility Testing, 1998. Performance
standards for antimicrobial susceptibility testing. Blood Safety
and Clinical Technology Guidelines on Standard Operating
Procedures for Microbiology. Eight Informational Supplement.
M100-S8 18 (1). NCCLS, Pennsylvania, USA.
Performance standards for antimicrobial susceptibility testing
- Antimicrobial Susceptibility Nccls
- Testing
NCCLS and Antimicrobial Susceptibility Testing, 1998. Performance
standards for antimicrobial susceptibility testing. Blood Safety
and Clinical Technology Guidelines on Standard Operating
Procedures for Microbiology. Eight Informational Supplement.
M100-S8 18 (1). NCCLS, Pennsylvania, USA.