Biosynthesis Of Metal Nanoparticles Research Articles

A comparative study of the biosynthesis of CuNPs by Niallia circulans G9 and Paenibacillus sp. S4c strains: characterization and application as antimicrobial agents

BackgroundBiosynthesis of metallic nanoparticles using microorganisms are a fabulous and emerging eco-friendly science with well-defined sizes, shapes and controlled monodispersity. Copper nanoparticles, among other metal particles, have sparked increased attention due to their applications in electronics, optics, catalysis, and antimicrobial agents.ResultsThis investigation explains the biosynthesis and characterization of copper nanoparticles from soil strains, Niallia circulans G9 and Paenibacillus sp. S4c by an eco-friendly method. The maximum reduction of copper ions and maximum synthesis CuNPs was provided by these strains. Biogenic formation of CuNPs have been characterized by UV–visible absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray analysis and transmission electron microscopy analysis. Using UV-visible spectrum scanning, the synthesised CuNPs’ SPR spectra showed maximum absorption peaks at λ304&308 nm. TEM investigation of the produced CuNPs revealed the development of spherical/hexagonal nanoparticles with a size range of 13–100 nm by the G9 strain and spherical nanoparticles with a size range of 5–40 nm by the S4c strain. Functional groups and chemical composition of CuONPs were also confirmed. The antimicrobial activity of the biosynthesized CuNPs were investigated against some human pathogens. CuNPs produced from the G9 strain had the highest activity against Candida albicans ATCC 10,231 and the lowest against Pseudomonas aeruginosa ATCC 9027. CuNPs from the S4c strain demonstrated the highest activity against Escherichia coli ATCC 10,231 and the lowest activity against Klebsiella pneumonia ATCC 13,883.ConclusionThe present work focused on increasing the CuNPs production by two isolates, Niallia circulans G9 and Paenibacillus sp. S4c, which were then characterized alongside. The used analytics and chemical composition techniques validated the existence of CuONPs in the G9 and S4c biosynthesized nano cupper. CuNPs of S4c are smaller and have a more varied shape than those of G9 strain, according to TEM images. In terms of antibacterial activity, the biosynthesized CuNPs from G9 and S4c were found to be more effective against Candida albicans ATCC 10,231 and E. coli ATCC 10,231, respectively.

Facile sonochemically-assisted bioengineering of titanium dioxide nanoparticles and deciphering their potential in treating breast and lung cancers: biological, molecular, and computational-based investigations.

Combining sonochemistry with phytochemistry is a modern trend in the biosynthesis of metallic nanoparticles (NPs), which contributes to the sustainability of chemical processes and minimizes hazardous effects. Herein, titanium dioxide (TiO2) NPs were bioengineered using a novel and facile ultrasound-assisted approach utilizing the greenly extracted essential oil of Ocimum basilicum. FTIR and UV-Vis spectrophotometry were used to confirm the formation of TiO2 NPs. The X-ray diffraction (XRD) analysis showed the crystalline nature of TiO2 NPs. TEM analysis revealed the spherical morphology of the NPs with sizes ranging from 5.55 to 13.89 nm. Energy-dispersive X-ray (EDX) confirmed the purity of the greenly synthesized NPs. TiO2 NPs demonstrated outstanding antitumor activity against breast (MCF-7) and lung (A-549) cancer cells with estimated IC50 values of 1.73 and 4.79 μg mL-1. The TiO2 NPs were cytocompatible to normal cells (MCF-10A) with a selectivity index (SI) of 8.77 for breast and 3.17 for lung cancer. Biological assays revealed a promising potential for TiO2 NPs to induce apoptosis and arrest cells at the sub-G1 phase of the cell cycle phase in both cancer cell lines. Molecular investigations showed the ability of TiO2 NPs to increase apoptotic genes' expression (Bak and Bax) and their profound ability to elevate the expression of apoptotic proteins (caspases 3 and 7). Molecular docking demonstrated strong binding interactions for TiO2 NPs with caspase 3 and EGFR-TK targets. In conclusion, the greenly synthesized TiO2 NPs exhibited potent antitumor activity and mitochondrion-based cell death against breast and lung cancer cell lines while maintaining cytocompatibility against normal cells.

Enhanced in vivo wound healing efficacy and excellent antibacterial, antifungal, antioxidant and anticancer activities via AgNPs@PCS

Today, wound healing is an important clinical problem that is often affected by microbial infection and not paying attention to this problem can cause irreparable damage to people. Biosynthesis of metal nanoparticles (NPs) has created a huge revolution in the field of nanomedicine due to their non-toxic, biocompatible, and stable characteristics. For this purpose, in this study, Petroselinum crispum seed extract (PCS) was applied to preparation of silver nanoparticles (AgNPs@PCS). The optimization of the silver nanoparticle synthesis involved adjusting the concentration of the silver salt, as well as the time and temperature parameters. After identifying the fabricated nanoparticles by FESEM, XRD, FT-IR, UV–Vis, TEM and EDS, their biological activity (like antibacterial, antifungal, antioxidant, anticancer, and wound treatment) was determined. The green synthesis of AgNPs was confirmed by several characteristics, including the surface plasmon response with a peak around 420 nm, the presence of both regular and heterogeneous sizes in the sample, and the observed color change from a clear solution to a brown color. The antimicrobial properties of the biofabricated AgNPs were investigated against fungal and various bacteria. The anticancer property of AgNPs@PCS was demonstrated by an IC50 value of 200 µg/ml after a 24-hour exposure on the MCF-7 cell line. Also, a dose-dependent antioxidant performance of AgNPs was found against the DPPH free radical. Histopathological evaluations of AgNPs@PCS ointment illustrated significant decrease in inflammatory cells. The results showed that vaseline ointment containing AgNPs@PCS prevented inflammation in the wound area and increased the number of fibroblast cells, which led to accelerated wound healing. Furthermore, in-vivo investigation showed the higher percentage of wound closure on days 7 and 14 was than the control group (Vaseline). Interestingly, the wound was completely closed after 21 days. Thus, we concluded that Petroselinum crispum-mediated silver nanoparticles show potential biological activity which can be used as nano-drug in clinical treatment.

Biosynthesis of metal nanoparticles and their testing on flax seeds

This work sets out to investigate a green-synthesized biopreparation produced by introducing iron or copper nanoparticles into a microbial liquid-phase biological product (LBP). The obtained nanoparticles were analyzed by diffuse reflectance IR spectroscopy and introduced into the LPB at the stage of its ripening in the LPB:particle solution volume ratio of 50:1. As a result, two new biopreparations – LPB-Fe and LPB-Cu – were obtained. All LPB samples, as well as iron and copper nanoparticles, underwent laboratory testing on flax seeds of Tverskaya variety. Iron or copper nanoparticles in the composition of biological preparations were found to affect positively the process of seed germination. In the LPB-Fe variant, seed germination ranged between 86–91%, which exceeded that in the control by 3–12%. In the LPB-Cu variant, seed germination ranged between 86–93%, which exceeded that in the control by 3–11%. However, in the latter variant, the maximum average length per seedling was 14.5–14.8 cm. The average length per seedling was significantly affected by watering the seeds with a solution containing only iron nanoparticles, with the maximum value of this parameter reaching 16.1±1.2 cm. According to the results obtained, this research direction has good prospects and requires additional experiments by varying the nanoparticle concentration in LBPs.

Prospects of plant-derived metallic nanopesticides against storage pests - A review

The desire to increase agricultural productivity and to alleviate food losses caused by insects during post-harvest storage periods has augmented the rampant use of unsafe chemo-synthetic pesticides. The elevated health risks on human or domestic animals and environmental pollution by chemo-pesticides have shifted the focus of getting eco-friendly pesticides from biological entities. Research on the nanotechnological application in agriculture has become popular and promising. The diversity among plant species as well as the possession of different insect-specific bioactive compounds makes them the favoured choice for exploring active ingredients, and the application of nanoscience has facilitated the development of effective nano-biopesticides. Varieties of phytochemical groups act as reducing- and stabilizing agents during the biosynthesis of metallic nanoparticles that would be operated as nanobiopesticides. Moreover, green synthesis of metallic nanoparticles or nano-conjugates, especially silver nanoparticles have been experimentally proven successful in controlling insects of stored food products. This review compiles phyto-derived metallic nanoparticles' potential and effectiveness against storage insects, and the analysis will augment research in designing and promoting the development of eco-friendly agrochemicals.

Adsorption of Ibuprofen as a pharmaceutical pollutant from aqueous phase using zinc oxide nanoparticles: Green synthesis, batch adsorption and biological activities.

Recent interest has focused on the biosynthesis of metal nanoparticles, particularly from plants. The production of precipitate served as an early indicator of the presence in the present study's use of ZnO nanoparticles green synthesis of these particles, which was further validated by; Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD). Additionally, the BET was used to calculate the surface area, which came out to be 119.12 m2 /g. Since the true effects of new pollutants, including medicines, on the environment and human health are not well understood, their presence in aquatic systems poses a severe hazard. For this reason, the antibiotic Ibuprofen (IBP) was absorbable to ZnO-NPs in this search. As opposed to fitting to Langmuir isothermally, the adsorption process was discovered to be pseudo-second-order kinetically, and the reaction was determined to be a chemisorption process. The process was endothermic and spontaneous, according to thermodynamic studies. Maximizing IBP removal from aqueous solution required the use of a Box-Behnken surface statistical design with four components, four levels, and response surface modelling. Solution pH, IBP concentration, duration, and dose were the four parameters that were utilized. The regeneration process, which is employed for five cycles with excellent efficiency, is the best benefit of using ZnO-NPs. Examine the elimination of pollutants from actual samples as well. However, the adsorbent is quite effective at reducing biological activity. At high concentrations of ZnO-NPs demonstrated notable antioxidant activity and RBC hemocompatibility and no discernible hemolysis was seen. ZnO-NPs demonstrated a notable percent suppression of α-amylase up to 53.6 % at 400 μg/mL, and so displayed potential as an antidiabetic. Cyclooxygenase was suppressed by ZnO-NPs in an anti-inflammatory test (COX-1 & COX-2) up to 56.32 and 52.04 % at a concentration of 400 μg/mL, respectively. Significant anti-Alzheimer potential was demonstrated by ZnO-NPs at 400 μg/mL by inhibiting Acetyl cholinesterase (AChE) and Butyl cholinesterase (BChE) up to 68.98 ± 1.62% and 62.36% respectively. We came to the conclusion that guava extract is helpful for ZnO-NP reduction and capping. The bioengineered nanoparticles could prevent Alzheimer's, diabetes, and inflammation and were biocompatible. This article is protected by copyright. All rights reserved.

Preparation and Characterization of Silver Nanoparticles Using Rosemary and Olive Leaf Aqueous Extracts

Nano technology is single of the current technologies that are used in several playing field as well as agriculture, Nano-particles are produced in various ways, one of which is the biological method, which is one of the easy, fast, inexpensive and environmentally safe methods. This reference study deals with the latest studies on the manufacture of microorganisms and plant extracts, Biosynthesis of metallic nanoparticles using plant extracts. This study aims to use extracts of olive leaves and rosemary leaves as a biological agent to reduce silver nitrate to silver nanoparticles and capping solutions at pH 6.5 the color of the extracts changed from brown to dark green after adding silver nitrate solution indicating the formation of silver nanoparticles. These nano compounds were characterized using X-ray Diffraction, Atomic Force Microscopy and UV-Visible spectrophotometer. Silver nanoparticles were characterized using UV-visible radiation Spectral analysis which showed the highest peaks for olive leaf and rosemary extracts, respectively, at 450nm and 590nm, When examining the extracts of silver nanoparticles for olive leaves and rosemary leaves characterized using X-ray Diffraction a peak at 2θ= 40 appeared indicating the presence of silver nanoparticles, Finally, when diagnosing silver nanoparticles using atomic force electron technology The given microscopy (AFM) showed limited bandwidth high molecular assemblies of silver nanoparticles of olive leaf and rosemary leaf extract respectively (0-8.4) and (0-31) nm.

The Activity of Vossia cuspidata Polysaccharides-Derived Monometallic CuO, Ag, Au, and Trimetallic CuO-Ag-Au Nanoparticles Against Cancer, Inflammation, and Wound Healing

The biosynthesis of metal nanoparticles using plant extracts is an eco-friendly and inexpensive solution that has strong potential and applications in science and industry. This study aims to synthesize Cu, Ag, and Au monometallic and trimetallic nanoparticles (NPs) using the extracted polysaccharides (PS) of Vossia cuspidata (Roxb.) Griff. leaves. Besides, the anti-cancer, anti-inflammatory, and wound healing potentials of the synthesized NPs were tested. The synthesized NPs were characterized using standard technological methods. We succeeded in green synthesizing CuO, Ag, Au, monometallic, and CuO-Ag-Au trimetallic NPs. The synthesized NPs had weak cytotoxicity at low concentrations (6.5 µg/ml), but the viability of cancer cells was reduced by increasing the concentration, suggesting that the synthesized NPs have potent anti-cancer properties against the cells. The synthesized NPs had 19.44–45.9 μg/ml cytotoxic activity (IC50) against the MCF-7 cell line, 16.50–51.92 μg/ml against A549, and 115.90–165.9 μg/ml for normal lung cells (WI-38). TMNPs were the most effective cytotoxic agents against all the tested cell lines, followed by AuNPs on MCF-7 and CuONPs on A549. The cotton fabric-treated TMNPs and CuONPs exhibited anti-inflammatory properties greater than fabric-treated AgNPs and AuNPs and showed the highest odema inhibition (84.61% and 79.28%, respectively). In the wound healing assay, CuONPs and TMNPs caused the highest percentages of inhibition (87.82% and 61.98%, respectively) for the wound compared to AgNPs and AuNPs. TMNPs and CuONPs were more efficient in restoring the tissue integrity of wounds than AgNPs and AuNPs. Accordingly, we recommend using TMNPs and CuONPs in the wound healing dressings.

Biosynthesis of metallic nanoparticles by bacterial cell-free extract.

The biosynthesis of metallic nanoparticles (MNPs), encompassing noble metals, metal oxides, and sulfides, has gained significant attention in recent years due to their unique properties and wide-ranging applications. However, traditional chemical synthesis methods often involve extreme conditions, harsh chemicals, and negative environmental impacts. Consequently, developing a simple, non-toxic, and eco-friendly approach for MNP synthesis is paramount. One promising method that addresses these concerns is using a bacterial cell-free extract (CFE) as a mediator for biosynthesis. Compared with other biosynthesis production methods, the purification process of MNPs synthesized using bacterial CFEs is much simpler, and CFE production is easier to standardize and reproduce. Bacterial CFEs are rich in various biomolecules, including proteins, enzymes, and peptides, which serve as both reducing and oxidizing agents during MNP formation. These biomolecules act as capping agents, contributing to the stability and monodisperse nature of MNPs. Using bacterial CFEs for MNP synthesis offers several advantages. Firstly, it aligns with eco-friendly practices as a biosynthesis approach. The non-toxic process minimizes environmental damage. Additionally, bacterial CFEs are cost-effective, making large-scale production economically viable. This review provides insights into these mechanisms, highlighting the role of CFE biomolecules and their impact on MNP characteristics. It also investigates the correlation between synthesis parameters, morphologies, and physical, chemical, and biological properties, allowing for tailored MNP design through the biosynthesis conditions. Despite its advantages, bacterial CFE-mediated biosynthesis faces challenges. This review addresses these challenges and discusses potential solutions. It also explores future perspectives, emphasizing areas for further investigation and innovation. In summary, using bacterial CFEs to synthesize MNPs offers significant advantages over other methods. It ensures eco-friendly, non-toxic, and cost-effective production. The review emphasizes the mechanisms and biomolecules involved, showcasing the potential for tailored MNP design. It also addresses challenges and prospects, paving the way for advancements in this field. Furthermore, the originality of this work lies in the exploitation of bacterial CFEs as a highly efficient and scalable platform for MNP synthesis.

A Review on Bioinspired and Green Synthesis of Silver Nanoparticles with Their Antimicrobial Activity

The biosynthesis of metal nanoparticles (NPs) using plant extracts is one of the simplest, most useful, affordable, and environmentally friendly solutions to prevent the use of dangerous chemicals. The unique antimicrobial properties of silver (Ag) NPs have attracted the most interest among all the other nanoparticles. Concerns regarding the synthesis of these NPs, including the use of hazardous solvents and precursor chemicals, microbial contamination and the creation of toxic byproducts, led to the development of the new alternative process known as "green synthesis." As a result, various environmentally acceptable methods for producing Ag NPs quickly using aqueous extracts of plant parts like bark, roots, leaves, and so forth have been published in recent years. We discuss contemporary advancements in the environmentally friendly manufacturing of AgNPs, their application as antifungal agents, and their mode of action in this study. This review provides insight into the environmentally friendly manufacturing of Ag NPs, their application as antifungal agents with their mode of action, as well as their future prospects.

Bacillus spp. as Bioagents: Uses and Application for Sustainable Agriculture.

Food security will be a substantial issue in the near future due to the expeditiously growing global population. The current trend in the agriculture industry entails the extravagant use of synthesized pesticides and fertilizers, making sustainability a difficult challenge. Land degradation, lower production, and vulnerability to both abiotic and biotic stresses are problems caused by the usage of these pesticides and fertilizers. The major goal of sustainable agriculture is to ameliorate productivity and reduce pests and disease prevalence to such a degree that prevents large-scale damage to crops. Agriculture is a composite interrelation among plants, microbes, and soil. Plant microbes play a major role in growth promotion and improve soil fertility as well. Bacillus spp. produces an extensive range of bio-chemicals that assist in plant disease control, promote plant development, and make them suitable for agricultural uses. Bacillus spp. support plant growth by N fixation, P and K solubilization, and phytohormone synthesis, in addition to being the most propitious biocontrol agent. Moreover, Bacilli excrete extracellular metabolites, including antibiotics, lytic enzymes, and siderophores, and demonstrate antagonistic activity against phytopathogens. Bacillus spp. boosts plant resistance toward pathogens by inducing systemic resistance (ISR). The most effective microbial insecticide against insects and pests in agriculture is Bacillus thuringiensis (Bt). Additionally, the incorporation of toxin genes in genetically modified crops increases resistance to insects and pests. There is a constant increase in the identified Bacillus species as potential biocontrol agents. Moreover, they have been involved in the biosynthesis of metallic nanoparticles. The main objective of this review article is to display the uses and application of Bacillus specie as a promising biopesticide in sustainable agriculture. Bacillus spp. strains that are antagonistic and promote plant yield attributes could be valuable in developing novel formulations to lead the way toward sustainable agriculture.

Glycyrrhiza glabra bio-inspire the growth of monodispersed iron oxalate nanoparticles: A sustainable catalyst for dyes degradation

The biosynthesis of metal nanoparticles using the plant itself (excluding the extraction process) is a novel option benefited with maximizing the use of the raw materials, minimizing the production cost, promoting the sustainability of the process, and preventing the use/release of toxic chemicals. A high performance iron oxalate heterogeneous nanocatalyst was bio-synthesized using Glycyrrhiza glabra and ascorbic acid through solid-state pathway. Based on detailed characterization, the results revealed the preparation of monodispersed iron oxalate nanoparticles with orthorhombic crystalline phase. The prepared iron oxalate showed a spherical-like shape with particle size in the range of 13–30 nm. The ascorbic acid reduces the Fe3+ to Fe2+ forming ferrous ascorbate which decomposed into iron oxalate. The hydroxyl and carbonyl groups present in the Glycyrrhiza glabra helped in capping and stabilizing the iron oxalate nanoparticles. The green-synthesized iron oxalate clearly showed an efficient catalytic performance in the reduction and oxidation of dyes for sequential catalytic cycles. Also, the green iron oxalate successfully catalyzed the degradation of the mixture of dyes. The proposed green catalyst was loaded to polymeric film for the easy-separation of the nanoparticles.

In vitro biosynthesis of iron selenide nanoparticles for imageable drug delivery platform

Biosynthesis of metal nanoparticles is an alternative route to obtain suitable materials for biomedical applications because neither toxic reducing reagents nor surfactants are required for the synthesis, unlike conventional chemical ways. In this study, we demonstrate the in vitro biosynthesis of FeSe nanoparticles using a recombinant fusion protein of Pseudomonas putida metallothionein and Arabidopsis thaliana phytochelatin synthase as the seeding sites under UV irradiation. The resulting FeSe nanoparticles exhibited distinguishable fluorescence properties promising for imageable drug-delivery application. Its demonstration as an imageable drug delivery vehicle is done through poly-γ-glutamic acid (PGA) encapsulation to form the pH-dependent structural changeable shells. Doxorubicin (DOX) was used as a model drug, so that a drug-delivery system of [email protected]@PGA was constructed. It was then administered to mice and assessed for its biodistribution over time. The results suggest that [email protected]@PGA is feasible to be used as an imageable drug-delivery platform.

GREEN SYNTHESIS OS SILVER NANOPARTICLES USING METHANOLIC EXTRACTS OF GENTIANA SEPTEMFIDA, ERYSIMUM CONTRACTUM AND CHELIDONIUM MAJUS AND EVALUATION OF ANTIBACTERIAL, ANTIFUNGAL AND CYTOTOXIC ACTIVITIES OF OBTAINED AGNPS

Biosynthesis of metallic nanoparticles is simple, effective, eco-friendly and inexpensive way. It is a non-toxic method. Biosynthesized nanoparticles are primarily biocompatible and can be used in biomedical applications. Silver nanoparticles (AgNPs) are known to have strong antibacterial effects against pathogenic bacteria and have shown antifungal, antiviral activities so they can be helpful not only for fighting against bacteria. In given study silver nanoparticles were biosynthesized using methanolic extracts of Gentiana septemfida, Erysimum contractum and Chelidonium majus. Obtained nanoparticles were evaluated for antibacterial and fungicidal activities against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus and Candida albicans. Also, their cytotoxic effects were evaluated on human lung carcinoma A-549, colon adenocarcinoma DLD-1, and healthy human skin fibroblasts WS1 cell lines. The results show antibacterial, antifungal and cytotoxic effects at different level for each type. Biosynthesis of silver nanoparticles is simple, cost effective, eco-friendly method and obtained nanoparticles have potential to be used as antibacterial, antifungal and cytotoxic agents.

Biosynthesis of Metallic Nanoparticles from Plants: Industrial Applications

Biosynthesis of Metallic Nanoparticles from Plants: Industrial Applications

Green synthesis of silver and gold nanoparticles and their potential applications as therapeutics in cancer therapy; a review

• Cancer is one of the world's most serious public health problems. • Nanotechnology has become increasingly popular in disease management in recent years, and it has a bright future in healing difficult incurable diseases, particularly cancer. • Metallic nanoparticles made through biosynthesis are environmentally friendly and biocompatible, and can be employed in cancer diagnostics, new treatments, and drug delivery systems. • This study provides an overview of current advances in the biosynthesis of metallic nanoparticles (silver (Ag) and gold (Au)) and their potential anti-cancer capabilities, with a focus on mechanisms of action, as well as future nano-therapeutic research opportunities. Cancer is one of the leading causes of death in the globe. Cancer arises when genes that control normal cell cycle and cell division are mutated, resulting in uncontrolled cell division and proliferation. To date, a variety of medications have been utilized to treat cancer; however, traditional chemotherapeutic agents have reduced bioavailability, quick renal clearance, uneven distribution, and significant adverse effects. Nanotechnology has grown quickly in recent years and offers a wide range of applications in the healthcare field. Bio-mediated nanoparticles (NPs) are low-cost, safe, and biocompatible, and they have piqued the interest of scientists all over the world. These nanoscale materials provide a viable cancer therapy due to their low risk profile and fewer side effects. Various metallic NPs have been developed to cure or diagnose cancer; silver (Ag) and gold (Au) are the most often used anti-cancer NPs. The production of reactive oxygen species (ROS) in cellular compartments is thought to be responsible for these NPs' anticancer properties, which leads to the activation of autophagic, apoptotic, and necrotic death pathways. We detailed current advances in the biosynthesis of Ag, Au NPs in this paper, with a focus on their mechanism of action. Nanotoxicity is also discussed, as well as the future prospects and opportunities for nanotherapeutics.

Optimization of biosynthesis of stabilized silver nanoparticles using bitter orange peel by-products and glycerol

Nowadays, the biosynthesis of metal nanoparticles (NPs) through eco-friendly, cost-effective, and sustainable methods has drawn considerable attention. In this study, the green synthesis of silver NPs using AgNO3 salt and the peel extract of bitter orange (Citrus aurantium) as a reducing agent was modeled and optimized by central composite design (CCD). Accordingly, the process parameters including pH (7–11), time (0–4 h), and the ratio of extract/salt solution (0:100–20:80 v/v) were considered to model the responses including the spectrophotometric wavelength of maximum absorbance (λmax) and the maximum absorbance value at λmax (Amax), which represented the size and concentration of Ag NPs, respectively. Additionally, the stabilizing effect of glycerol (ratio of glycerol to salt 0–10 g/g) on the optimum treatment was studied using spectrophotometric and SEM analyses. The results showed that the quadratic and linear models were acceptably fitted to the experimental responses of Amax and λmax, respectively. The optimization results demonstrated that the optimal reaction parameters to achieve the maximum Amax were pH = 10.92, time = 3.5 h and ratio of extract/salt = 17.94:82.06 (v/v). Furthermore, glycerol could favorably play a stabilizer role in the optimum biosynthesized Ag NPs during the reaction and 14 days of storage at room temperature. The ICP-OES and TEM analyses of the stabilized Ag NPs (with 2.5 g/g glycerol) showed the presence of Ag element as nanospheres with ∼20 nm in size. The Ag NPs had great antibacterial properties against Staphylococcus aureus and Escherichia coli. Therefore, the bitter orange peel extract and glycerol could be promisingly used as novel reducing and stabilizing agents, respectively, to synthesize nanosilver via an eco-friendly and economical green approach.

Cytotoxicity, antifungal, antioxidant, antibacterial and photodegradation potential of silver nanoparticles mediated via Medicago sativa extract

The biosynthesis of metallic nanoparticles is on a sharp rise as they have growing applications in environmental and biomedical sciences. This study reports an eco-friendly and cost-effective methodology for synthesizing biogenic silver nanoparticles (AgNPs) using the extract of Medicago sativa (M. sativa) cultivated in South Khorasan. The parameters used in the synthesis process were optimized to obtain uniformly distributed AgNPs in suitable sizes. The morphological, structural, and bonding characteristics of M. sativa extract-based AgNPs (MSE-AgNPs) were explored using FTIR, FESEM, EDS, TEM, XRD, UV–Vis, and DLS techniques. UV–Vis spectroscopy confirmed the formation of MSE-AgNPs by observing the typical surface plasmon resonance (SPR) peak at 419 nm. XRD, FESEM, TEM, and DLS analyses confirmed the formation of face-centered cubic (fcc) crystalline structure, spherical/elliptical morphology, the average particle size of 15–35 nm, and highly stable MSE-AgNPs. Green synthesized MSE-AgNPs indicated a significant antioxidant activity (78%) compared to M. sativa extract (32%). As such, the synthesized MSE-AgNPs revealed a potential antioxidant activity towards the DPPH radicals. The biologically synthesized MSE-AgNPs exhibited highly potential antibacterial and antifungal activities against Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus epidermidis, Enterococcus faecalis, Staphylococcus aureus, and Candida albicans with the minimum inhibitory concentration (MIC) values of 62.5, 125, 125, 1000, 125, 1000, and 31.25 µg/mL, respectively. In vitro cytotoxicity of the MSE-AgNPs against human fibroblast (HF) cells indicated a dose–response activity (with IC50 value of 18 µg/mL). Moreover, the AgNPs revealed efficient photocatalytic degradation of thymol blue (TB) as an anionic dye and malachite green (MG) as a cationic dye under sunlight and UV irradiations. Up to 94.37% and 90.12% degradation rates were obtained for MG and TB within only 100 min of UV irradiation. These observations signify that synthesized MSE-AgNPs can have great potential for biological and environmental applications.

Green synthesis of Ag nanoparticles from Leucus aspera and its application in anticancer activity against alveolar cancer

Leucus aspera is a perennial plant traditionally used as an herbal medicine in many countries. The biosynthesis of metal nanoparticles using medicinal plants is not only economical but also environmentally friendly as well as having miscellaneous biomedical applications. In this study, Leucus aspera extract as a stabilising and reducing agent was utilised to synthesise Ag nanoparticles in the aqueous medium. In addition, the anti-alveolar cancer property of AgNPs was investigated in the in vitro condition. Various techniques containing UV–Vis. spectroscopy, FT-IR spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometry (EDS) were used to characterise the synthesised nanoparticles. On the other hand, the MTT assay was run to evaluate the cytotoxicity activity of AgNPs. The crystal size of AgNPs, according to the XRD analysis, was 34.22 nm. Moreover, the uniform spherical morphology ranging from 40.67 to 58.17 nm was detected in the SEM images for the biosynthesised nanoparticles. In the antioxidant test, the IC50 of AgNPs and BHT against DPPH free radicals were 87 and 41 µg/mL, respectively. The synthesised nanocomposite had very low cell viability and high anti-alveolar cancer activities against A549 cell line without any cytotoxicity on the normal cell line (HUVEC). The viability of malignant alveolar cell line reduced dose-dependently in the presence of Ag NPs. Perhaps notable anti-alveolar cancer activities of the synthesised nanocomposite against common alveolar cancer cell line are linked to their antioxidant activities.

Biosynthesis of metal nanoparticles and metal oxidesand their use as components of fertilizers and preparations for plant growing (literature review)

A promising direction in agriculture is the use of metal nanoparticles as nanofertilizers, which can increase the yield of agricultural crops and, at the same time, minimize the frequency of fertilization due to the long-term release of nutrients. One of the environmentally safest and cheapest methods of synthesizing metal nanoparticles is biosynthesis using plant extracts. During the redox reaction, proteins, carbohydrates, organic acids, phenols and other metabolites are able to transfer electrons to metal cations, restoring their charge to zero on the nanometer scale. This article, based on publications on the issue under study by authors from the United States of America, Europe and the Middle East, China and India, describes the biosynthesis of nanoparticles of zinc oxide, copper and copper oxide, iron and iron oxide, as well as manganese and manganese oxide using the formation of plant extracts, and data on the use of these metals and their oxides as nanofertilizers and preparations for plant growing are presented. It has been shown that the use of metal nanoparticles and their oxides as fertilizers is more effective than conventional compounds used as fertilizers. This is probably due to the fact that it is easier for nanoparticles to penetrate through the plant membrane, as well as to pass into a form accessible to plants in comparison with conventional analogs. The positive effect of the influence of nanoparticles on plants is expressed in the elongation of the roots and shoots of model plants and an increase in the biomass of seedlings. In addition, the amount of chlorophyll in the leaves increases, and some biochemical processes also change, for example, the amount of antioxidant enzymes increases, which makes it possible to increase the stress resistance of plants.