Green-synthesized Metal Nanoparticles Research Articles

Efficient removal of environmental pollutants by green synthesized metal nanoparticles of Clitoria ternatea

Prevention and management of water pollution are becoming a great challenge in the present scenario. Different conventional methods like carbon adsorption, ion exchange, chemical precipitation, evaporation, and biological treatments remove water pollutants. Nowadays, the requirement for effective, non-toxic and safe waste management strategies is very high. Nanomaterials have been explored in various fields due to their unique characteristics. Green synthesis of nanomaterial is becoming more popular due to their safety, non-toxicity, and ease of scale-up technology. Metal nanoparticles can be synthesized using a green synthesis method using biological sources provided by eco-friendly, non-hazardous nanomaterials with superior properties to bulk metals. Hence, this study has designed a green synthesis of magnetic (cobalt oxide) and noble (gold) nanoparticles from the fresh flowers of Clitoria ternatea. The flavonoids and polyphenols in the extract decreased the energy band gap of cobalt oxide and gold nanoparticles; hence, the capping of the natural constituents in Clitoria ternatea helped form stable metal nanoparticles. The cobalt oxide and gold nanoparticles are evaluated for their potential for eliminating organic pollutants from industrial effluent. The novelty of this present work represents the application of cobalt oxide nanoparticles in the removal of organic pollutants and a comparative study of the catalytic behaviour of both metal nanoparticles. The degradation of bromophenol blue, bromocresol green, and 4–nitrophenol in the presence of gold nanoparticles was completed in 120, 45, and 20 min with rate constants of 3.7 × 10−3/min, 6.9 × 10−3/min, and 16.5 × 10−3/min, respectively. Similarly, the photocatalysis of bromophenol blue, bromocresol green, and 4–nitrophenol in the presence of cobalt oxide nanoparticles was achieved in 60, 90, and 40 min with rate constants of 2.3 × 10−3/min, 1.8 × 10−3/min, and 1.7 × 10−3/min, respectively. The coefficient of correlation (R2) values justify that the degradation of organic pollutants follows first-order kinetics. The significance of the study is to develop green nanomaterials that can be used efficiently to remove organic pollutants in wastewater using a cost-effective method with minimal toxicity to aquatic animals. It has proved to be useful in environmental pollution management.

Green synthesis of silver nanoparticles using Moringa oleifera and its efficacy against gram-negative bacteria targeting quorum sensing and biofilms

AbstractGram-negative pathogenic bacteria are the leading cause of high morbidity and mortality in humans globally. The majority of such pathogens has gained the status of multidrug resistance and requires the development of new anti-pathogenic agent. Moringa oleifera is a widely distributed and quickly proliferating medicinal plant, making it an easy source for extracting bioactive components. It is rich in bioactive compounds which can act as stabilizing and reducing agents during the synthesis of silver nanoparticles. It is well-recognized for its several medical benefits, including antibacterial action. As a result, it is an excellent option for synthesizing AgNPs with improved antibacterial characteristics. Considering the above properties, less explored Moringa oleifera was used for the green synthesis of nanoparticles. Targeting biofilms and virulence factors of Gram-negative bacteria by green synthesized metal nanoparticles is an alternative approach to combat antimicrobial resistance. Silver nanoparticles (MO-AgNPs) synthesized using Moringa oleifera leaf (MOL) extract were characterized using Ultraviolet–visible spectroscopy (UV–vis spectroscopy), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy-energy dispersive X-ray analysis (SEM–EDX), Transmission Electron Microscopy (TEM), and X-Ray Diffraction analysis (XRD). The absorption spectra of silver nanoparticles showed a band of absorption near 440 nm, associated with spherical silver nanoparticles. At sub-minimum inhibitory concentrations (sub-MICs), the MO-AgNPs inhibit the Quorum Sensing-mediated virulence factors and biofilm formation against three Gram-negative bacteria (Escherichia fergusonii, Serratia marcescens, and Chromobacterium violaceum). QS-mediated virulence factors in test bacteria were reduced by 80.67% (violacein), prodigiosin production (77.45%), exoprotease activity (76.02%), and swarming motility (86.5%). MO-AgNPs also demonstrated broad-spectrum antibiofilm activity against test bacteria, ranging from 77.95 to 82.4% inhibition. Microscopic analysis of biofilms showed significant structural change and inhibition. Our results demonstrate appreciable in vitro activity of MO-AgNPs against the selected pathogens, which could be used as an alternative therapeutic agent for treating infection caused by drug-resistant bacteria and preventing biofilm development by bacteria on medical devices and other surfaces. Graphical abstract

Green synthesis of silver nanoparticles derived from lemon and pomegranate peel extracts to combat multidrug-resistant bacterial isolates

BackgroundMultidrug-resistant (MDR) bacteria are acknowledged as one of the main factors contributing to chronic illnesses and fatalities globally. Numerous diseases, including bloodstream infections, pneumonia, urinary tract infections, and surgical site infections, can be brought on by MDR bacteria. Therefore, a crucial topic of continuing research is the development of a novel and different treatment for MDR microbial pathogens. This work is introduce an alternative method for elimination of MDR bacterial isolates which are causative agents of urinary tract infection among people in Egypt. In our study, we need a novel strategy to combat MDR bacteria by green-synthesized metal nanoparticles (MNPs). That is due to the ability of MNPs to penetrate the cell wall and the cell membrane of gram-positive and gram-negative bacteria. MethodsClinical isolates of MDR bacteria had their antibiotic susceptibility assessed before being molecularly identified using 16 s rRNA, sequencing, and phylogenetic analysis. Also, genetic profiles of isolated strains were performed using ISSR and SDS-PAGE. Finally, characterized plant-mediated silver nanoparticles derived from lemon and pomegranate peel extracts were evaluated against isolated multidrug-resistant bacterial stains. ResultsIn our present trial, one-hundred urine samples were collected from 71 females and 29 males complaining of UTI (urinary tract infection) symptoms. One-hundred microbial isolates were isolated, including 88-g negative and only 8-g positive bacteria in addition to four yeast isolates (Candida species). A total of 72% of the isolated bacteria showed MDR activity. The most prevalent MDR bacterial isolates (Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecalis, and Klebsiella pneumoniae) were identified through 16S rDNA PCR sequencing as with accession numbers OP741103, OP741104, OP741105, OP741106, and OP741107, respectively. Lemon and pomegranate-mediated silver nanoparticles [Ag-NPs] were characterized by UV spectroscopy, FTIR, XRD, and TEM with average size 32 and 28 nm, respectively. Lemon and pomegranate-mediated silver nanoparticles [Ag-NPs] showed an inhibitory effect on the selected five MDR isolates at MIC 50 and 30 µg/mL, respectively. These common bacterial isolates were also genetically examined using ISSR PCR, and their total protein level was evaluated using SDS-PAGE, showing the presence of distinct genetic and protein bands for each bacterial species and emphasizing their general and protein composition as a crucial and essential tool in understanding and overcoming MDR behavior in UTI patients. ConclusionsLemon and pomegranate-mediated silver nanoparticles [Ag-NPs] were found to have an inhibitory effect on MDR isolates. Therefore, the study suggests that [Ag-NPs] could be a potential treatment for MDR UTI infections caused by the identified bacterial species.

Applications of Green Synthesized Metal Nanoparticles - a Review.

Green nanotechnology is an emerging field of science that focuses on the production of nanoparticles by living cells through biological pathways. This topic plays an extremely imperative responsibility in various fields, including pharmaceuticals, nuclear energy, fuel and energy, electronics, and bioengineering. Biological processes by green synthesis tools are more suitable to develop nanoparticles ranging from 1 to 100nm compared to other related methods, owing to their safety, eco-friendliness, non-toxicity, and cost-effectiveness. In particular, the metal nanoparticles are synthesized by top-down and bottom-up approaches through various techniques like physical, chemical, and biological methods. Their characterization is very vital and the confirmation of nanoparticle traits is done by various instrumentation analyses such as UV-Vis spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), atomic force microscopy (AFM), annular dark-field imaging (HAADF), and intracranial pressure (ICP). In this review, we provide especially information on green synthesized metal nanoparticles, which are helpful to improve biomedical and environmental applications. In particular, the methods and conditions of plant-based synthesis, characterization techniques, and applications of green silver, gold, iron, selenium, and copper nanoparticles are overviewed.

Current Trends and Prospects for Application of Green Synthesized Metal Nanoparticles in Cancer and COVID-19 Therapies.

Cancer and COVID-19 have been deemed as world health concerns due to the millions of lives that they have claimed over the years. Extensive efforts have been made to develop sophisticated, site-specific, and safe strategies that can effectively diagnose, prevent, manage, and treat these diseases. These strategies involve the implementation of metal nanoparticles and metal oxides such as gold, silver, iron oxide, titanium oxide, zinc oxide, and copper oxide, formulated through nanotechnology as alternative anticancer or antiviral therapeutics or drug delivery systems. This review provides a perspective on metal nanoparticles and their potential application in cancer and COVID-19 treatments. The data of published studies were critically analysed to expose the potential therapeutic relevance of green synthesized metal nanoparticles in cancer and COVID-19. Although various research reports highlight the great potential of metal and metal oxide nanoparticles as alternative nanotherapeutics, issues of nanotoxicity, complex methods of preparation, biodegradability, and clearance are lingering challenges for the successful clinical application of the NPs. Thus, future innovations include fabricating metal nanoparticles with eco-friendly materials, tailor making them with optimal therapeutics for specific disease targeting, and in vitro and in vivo evaluation of safety, therapeutic efficiency, pharmacokinetics, and biodistribution.

Green synthesized metal nanoparticles as an ecofriendly measure for plant growth stimulation and disease resistance

Nanotechnology, as an advanced technology plays a vital role in various aspects of plants. In recent past, nanoparticles synthesized via biological routes received attention than that of other means of synthesis due to their cost effectiveness and ecofriendly nature. This review is aimed at providing a comprehensive compilation of information on ecofriendly nature of green synthesized nanoparticles especially in plant disease resistance and plant growth enhancement. According to the available literature, among the different biological sources used for green synthesis of nanoparticles, plant based green synthesis has become more popular in recent years because of their non-toxic nature, higher availability and accessibility. The effects of green synthesized nanoparticles are primarily dose dependent and vary with the characteristics of nanoparticle and the plant. Furthermore, application of such nanoparticles at optimum concentration has notably inhibited the number of phytopathogens and favoured the growth and yield attributes of crop plants. Using the green synthesized nanoparticle in combination with other materials were found to have synergistic effects in disease resistance and causes growth enhancement in crop plants. Even though, numerous inherent benefits are there in the green synthesized nanoparticles, constraints such as toxicity at higher concentrations and unsafe disposal to the environment may limit the continuous application and opens new avenues for future studies.

Biosynthesis of iron nanoparticles using brown algae Spatoglossum asperum and its antioxidant and anticancer activities through in vitro and in silico studies

Green synthesized metal nanoparticles play a significant role in biomedical applications. This investigation focused on eco-friendly synthesized iron nanoparticles using marine brown algae Spatoglossum asperum which was evaluated for its anticancer and free radical scavenging activity against glioblastoma. The formation of iron nanoparticles confirmed the surface plasmon resonance (SPR) peak at 400 nm by UV visible Spectrum. X-ray diffraction spectroscopy analysis confirmed the crystalline structure of iron nanoparticles. Fourier Transform Infrared spectroscopy analysis was used to identify the functional groups in the algae extract that are involved in the ferrous ion oxidation into iron nanoparticles (Fe3O4NPs). Scanning electron microscope images indicated that the produced nanoparticles were spherical and 16 nm in size, as had been predicted. The S. asperum-mediated Fe3O4NP has shown potential antioxidant activities against 2,2-diphenyl-1-picrylhydrayl and H2O2 activity and its scavenging inhibition was 80.13% and 62.21% determined at 50 µg/mL. The anticancer activity of the synthesized Fe3O4NP against human glioblastoma cells (LN-18) was analyzed and the Fe3O4NPs half inhibitory concentration was found to be 19.24 µg/mL. The findings of the investigation evaluated the binding affinities of different proteins expressed in glioblastoma with bioactive compounds in the S. asperum by performing molecular docking by autodock vina version 4.2. The results of the present investigation revealed that S. asperum-mediated iron oxide nanoparticles exhibited antioxidant potential and effectively suppressed the proliferation of glioblastoma cancer cells.

Efficacy of metal nanoparticles as a control tool against adult mosquito vectors: A review

Presently, there is a need to develop effective and novel modes of control for mosquitoes, which remain a key driver of infectious disease transmission throughout the world. Control methods for these vectors have historically relied on a limited number of active ingredients (AIs) that have not experienced significant change in usage since the mid-20th century. The resulting development of widespread insecticide resistance has consequently increased the risk for future vector-borne disease outbreaks. Recently, metal nanoparticles have been explored for potential use in mosquito control due to their demonstrated toxicity against mosquitoes at all life stages. However, the majority of studies to date have focused on the larvicidal efficacy of metal nanoparticles with few studies examining their adulticidal potential. In this review, we analyze the current literature on green synthesized metal nanoparticles and their effect on adult mosquitoes.

Green Synthesis and Characterization of ZnO Nanoparticles Using Pelargonium odoratissimum (L.) Aqueous Leaf Extract and Their Antioxidant, Antibacterial and Anti-inflammatory Activities.

Nanoparticles (NPs) exhibit distinct features compared to traditional physico-chemical synthesis and they have many applications in a wide range of fields of life sciences such as surface coating agents, catalysts, food packaging, corrosion protection, environmental remediation, electronics, biomedical and antimicrobial. Green-synthesized metal NPs, mainly from plant sources, have gained a lot of attention due to their intrinsic characteristics like eco-friendliness, rapidity and cost-effectiveness. In this study, zinc oxide (ZnO) NPs have been synthesized employing an aqueous leaf extract of Pelargonium odoratissimum (L.) as a reducing agent; subsequently, the biosynthesized ZnO NPs were characterized by ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). Moreover, aqueous plant leaf extract was subjected to both qualitative and quantitative analysis. Antioxidant activity of ZnO NPs was assessed by DPPH assay, with varying concentrations of ZnO NPs, which revealed scavenging activity with IC50 = 28.11 μg mL−1. Furthermore, the anti-bacterial efficacy of the green synthesized ZnO NPs against four foodborne pathogenic bacterial strains was examined using the disk diffusion assay, and Staphylococcus aureus (ATCC 8095), Pseudomonas aeruginosa (ATCC10662) and Escherichia coli (ATCC 25922) were found to be the most sensitive against biosynthesized ZnO NPs, whereas the least sensitivity was shown by Bacillus cereus (ATCC 13753). The anti-inflammatory effect was also evaluated for both ZnO NPs and the aqueous leaf extract of P. odoratissimum through the human red blood cells (HRBC) membrane stabilization method (MSM) in vitro models which includes hypotonicity-induced hemolysis. A maximum membrane stabilization of ZnO NPs was found to be 95.6% at a dose of 1000 μg mL−1 compared with the standard indomethacin. The results demonstrated that leaf extract of P. odoratissimum is suitable for synthesizing ZnO NPs, with antioxidant, antibacterial as well as superior anti-inflammatory activity by improving the membrane stability of lysosome cells, which have physiological properties similar to erythrocyte membrane cells and have no hemolytic activity. Overall, this study provides biosynthesized ZnO NPs that can be used as a safe alternative to synthetic substances as well as a potential candidate for antioxidants, antibacterial and anti-inflammatory uses in the biomedical and pharmaceutical industries.

Green synthesis of metal-based nanoparticles for sustainable agriculture

The large-scale use of conventional pesticides and fertilizers has put tremendous pressure on agriculture and the environment. In recent years, nanoparticles (NPs) have become the focus of many fields due to their cost-effectiveness, environmental friendliness and high performance, especially in sustainable agriculture. Traditional NPs manufacturing methods are energy-intensive and harmful to environment. In contrast, synthesizing metal-based NPs using plants is similar to chemical synthesis, except the biological extracts replace the chemical reducing agent. This not only greatly reduces the used of traditional chemicals, but also produces NPs that are more economical, efficient, less toxic, and less polluting. Therefore, green synthesized metal nanoparticles (GS-MNPs) are widely used in agriculture to improve yields and quality. This review provides a comprehensive and detailed discussion of GS-MNPs for agriculture, highlights the importance of green synthesis, compares the performance of conventional NPs with GS-MNPs, and highlights the advantages of GS-MNPs in agriculture. The wide applications of these GS-MNPs in agriculture, including plant growth promotion, plant disease control, and heavy metal stress mitigation under various exposure pathways, are summarized. Finally, the shortcomings and prospects of GS-MNPs in agricultural applications are highlighted to provide guidance to nanotechnology for sustainable agriculture.

The Potential Application of Green-Synthesized Metal Nanoparticles in Dentistry: A Comprehensive Review.

Orodental problems have long been managed using herbal medicine. The development of nanoparticle formulations with herbal medicine has now become a breakthrough in dentistry because the synthesis of biogenic metal nanoparticles (MNPs) using plant extracts can address the drawbacks of herbal treatments. Green production of MNPs such as Ag, Au, and Fe nanoparticles enhanced by plant extracts has been proven to be beneficial in managing numerous orodental disorders, even outperforming traditional materials. Nanostructures are utilized in dental advances and diagnostics. Oral disease prevention medicines, prostheses, and tooth implantation all employ nanoparticles. Nanomaterials can also deliver oral fluid or pharmaceuticals, treating oral cancers and providing a high level of oral healthcare. These are also found in toothpaste, mouthwash, and other dental care products. However, there is a lack of understanding about the safety of nanomaterials, necessitating additional study. Many problems, including medication resistance, might be addressed using nanoparticles produced by green synthesis. This study reviews the green synthesis of MNPs applied in dentistry in recent studies (2010–2021).

Nanoforms of essential metals: from hormetic phytoeffects to agricultural potential.

Vital plant functions require at least six metals (copper, iron, molybdenum, manganese, zinc, and nickel), which function as enzyme cofactors or inducers. In recent decades, rapidly evolving nanotechnology has created nanoforms of essential metals and their compounds (e.g. nZnO, nFe2O3) with a number of favourable properties over the bulk materials. The effects of nanometals on plants are concentration-dependent (hormesis) but also depend on the properties of the nanometals, the plant species, and the treatment conditions. Here, we review studies examining plant responses to essential nanometal treatments using a (multi)omics approach and emphasize the importance of gaining a holistic view of the diverse effects. Furthermore, we discuss the beneficial effects of essential nanometals on plants, which provide the basis for their application in crop production as, for example, nanopriming or nanostimulator agents, or nanofertilizers. As lower environmental impact and increased yield can be achieved by the application of essential nanometals, they support sustainable agriculture. Recent studies have actively examined the utilization of green-synthesized metal nanoparticles, which perfectly fit into the environmentally friendly trend of future agriculture. Further knowledge is required before essential nanometals can be safely applied in agriculture, but it is a promising direction that is timely to investigate.

Application of Green Synthesized Metal Nanoparticles in the Photocatalytic Degradation of Dyes and Its Mathematical Modelling Using the Caputo–Fabrizio Fractional Derivative without the Singular Kernel

Textile dyes are untreated discharge into the environment which results in a significant increase in water pollution levels worldwide. Due to the continuous addition of toxic organic dyes, a necessary strategic model is required for the complete degradation of dyes in textile effluent. This paper considers the possibility of biological synthesis of silver and iron nanoparticles and their use in photocatalytic degradation. The immediate change of silver nitrate solution occurring from colorless to brown is observed after the addition of the aqueous leaf extract, indicating the successive reduction of Ag+ ions to the Ag nanoparticles. These formed Ag nanoparticles were subjected to examine the photocatalytic activity under the solar radiation for the degradation of methyl orange. Green synthesized Ag nanoparticles were found to successfully degrade methyl orange up to 95% between 70 hours than the initial exposure time. The absorbance of methyl orange was measured at 465 nm. The present paper is focused on fractional mathematical modelling of dye degradation in textile effluents using the Caputo–Fabrizio fractional derivative without the singular kernel. The iterative Laplace transform method is employed to obtain an analytic solution for the absorption transport equation. The obtained experimental results showing significant removal of dyes from textile wastewater are compared using modelling results. The innovative approach is in outstanding agreement with the findings of the experiment. The mathematical modelling for the dye removal process helps to design suitable environmental management studies to reduce the adverse effect caused by toxic wastewater. Model validation has been shown by comparing analytical simulated solutions with experimental results for photocatalytic degradation using silver and iron nanoparticles as eco-friendly and low-cost agents.

Pharmaceutical and Biomedical Applications of Green Synthesized Metal and Metal Oxide Nanoparticles.

Due to the rapid growth in life threatening diseases such as cancer, diabetes, chronic wound and HIV/AIDS along with rise of side effects of the current treatments, world is now focusing to utilize new treatment options. Currently, the development of green nanotechnology field seems as a potential alternate for diseases diagnosis and treatment by preparation of various sizes and shapes of nanomaterials. This review is to present the explored biological sources in synthesis of nanomaterials particularly metal and metal oxides nanoparticles and critical review of the applications of biosynthesized nanoparticles in pharmaceutical and biomedical fields. In this review, the various biological sources including bacteria, fungi, algae and plants used in synthesis of nanomaterials and mechanism involved in preparation are elaborated. In addition, biosynthesized nanomaterials applied as drug delivery system for anticancer, antibiotic, antidiabetic agent and functioned as potential diagnostic, antimicrobial, anticancer and wound healing candidates are comprehensively reviewed. The synthesized metal and metal oxides from green protocol proved to have advantages such as being biocompatible, effective and cheap. Furthermore, the green synthesized metal and metal oxide nanoparticles showed to possess prominent physical, chemical and biological properties that can be efficiently utilized for pharmaceutical and biomedical applications. The information gathered in this review will provide a baseline for exploring more potential usage of green synthesized metal and metal oxide nanomaterials for various other applications. However, a concrete understanding of the safety of these nanomaterials is still needed to minimize the potential side effects.

Metal Nanoparticles from Algae: A Green Approach for the Synthesis, Characterization and their Biological Activity

In recent time, green synthesis of metal nanoparticles is the latest developing technology and received prodigious interest because it is easy, environmentally pristine, non-fouling, antitoxic, and lowcost approach. Green route of biogenic synthesis of metal nanoparticles via microbes such as bacteria, fungi, virus, yeast and algae has the potential to deliver sustainable and enviro safe protocol. Green synthesized metal nanoparticles are the most optimistic and novel agent for various catalytic and biological activities as antibacterial, antiviral, anticancer etc. without any toxic effects. Here, we reviewed algae-mediated green synthesis of metal and metal oxide nanoparticles and their biological activity. Algae are photoautotrophic, eukaryotic, aquatic, unicellular or multicellular organisms. Algae commonly used for biosynthesis because they grow rapidly, their biomass growth on average ten times faster than higher plants and easy to handle experiments with algal species. Different algal strains such as red, green and brown algae are using for the green synthesis of metal nanoparticles. Algae contain bioactive molecules and secondary metabolites that act as reducing, capping and stabilizing agent for manufacturing in nanoparticles. Biogenically synthesized metal and metal oxide nanoparticles characterized by different techniques such as UV-visible spectroscopy, SEM (scanning electron microscopy), HR-TEM (high-resolution transmission electron microscopy), XRD (X-ray diffraction), TGA (thermogravimetric analysis), DLS (dynamic light scattering) zeta potential and exhibited biological activity. In future, research algal production of metal nanoparticles can be explored by the use of different microalgae and their applications in different areas such as biological activity, catalytic activity in the synthesis of organic compounds, medical diagnose and synthesis of nanocomposite, lipid nanoparticles and antibiofilm.

Green Synthesized Metal Nanoparticles, Characterization and its Antidiabetic activities-A Review

The recent progress in the area of science and technology is the emergence of nanotechnology, and that having its role in all disciplinary field. In the nanotechnology, green way of metal nanoparticles synthesis plays an essential role nowadays. The advantages of using plant extract in the metal nanoparticles synthesis is less toxic, economic, environmentally friendly. The involvement of metal nanoparticles in the management of various chronic non-communicable diseases leads to the cause for new field Nano medicine. The management for various serious diseases without any side effect is the ultimate aim of all researchers in the scientific field with the help of nanomaterials and nanostructures. Diabetes mellitus kills most of the population next to cancer worldwide, in India diabetes mellitus death rate is going to be expected in the first place by 2045 by WHO. Though various medicinal plants were used for the curative application of diabetes mellitus, the nanotechnology gives insights into the research field for the biomedical application of metal nanoparticles. The nanomedicine in the drug delivery system has emerged its outlook and its mechanism of action were predicted by the researchers at present. This review discusses the recent reports of various green synthesized metal nanoparticles, its characterization and its antidiabetic activities both by in vitro and in vivo approaches.

A systematic review on anti-malarial drug discovery and antiplasmodial potential of green synthesis mediated metal nanoparticles: overview, challenges and future perspectives

BackgroundThe recent emergence in Southeast Asia of artemisinin resistance poses major threats to malaria control and elimination globally. Green nanotechnologies can constitute interesting tools for discovering anti-malarial medicines. This systematic review focused on the green synthesis of metal nanoparticles as potential source of new antiplasmodial drugs.MethodsSeven electronic database were used following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.ResultsA total of 17 papers were included in the systematic review. 82.4% of the studies used plant leaves to produce nanoparticles (NPs) while three studies used microorganisms, including bacteria and fungi. Silver was the main metal precursor for the synthesis of NPs. The majority of studies obtained nanoparticles spherical in shape, with sizes ranging between 4 and 65 nm, and reported no or little cytotoxic effect of the NPs. Results based on 50% inhibitory concentration (IC50) varied between studies but, in general, could be divided into three NP categories; (i) those more effective than positive controls, (ii) those more effective than corresponding plant extracts and, (iii) those less effective than the positive controls or plant extracts.ConclusionsThis study highlights the high antiplasmodial potential of green-synthesized metal nanoparticles thereby underscoring the possibility to find and develop new anti-malarial drugs based on green synthesis approaches. However, the review also highlights the need for extensive in vitro and in vivo studies to confirm their safety in humans and the elucidation of the mechanism of action.Graphical abstract

Green synthesized metal nanoparticles as a selective inhibitor of human osteosarcoma and pathogenic microorganisms

Nanobiotechnology gained at most importance in the current health-care systems. The present study reports the synthesis and characterization of silver and gold nanoparticles which in turn act as a selective inhibitor of human osteosarcoma. The in vitro anticancer studies on U2OS produced IC50 values in the therapeutic range of 29.22 ± 0.42 and 32.83 ± 0.81 μg/mL for silver and gold nanoparticles, while the fibroblast cells (L929) produced IC50 values of 141.26 ± 2.5 and 157.23 ± 2.11 μg/mL for silver and gold nanoparticles, respectively. The growth and action of infectious pathogens can be inhibited by the synthesized nanoparticles. The silver nanoparticles is used to scavenge the hydrogen peroxide and served as a sensor. The time-conserving microwave-assisted nanoparticle fabrication procedure is used here at the natural pH. Silver and gold nanoparticles have surface plasmon resonance peaks at 437 and 553 nm, respectively. The Fourier Transform Infrared spectroscopy fingerprints the role of amide groups of proteins in the synthesis and stabilization process. Transmission electron microscopic analysis proved the spherical geometry of silver and gold nanoparticles with an average size of 20.49 ± 6.68 nm and 25.05 ± 7.31 nm, respectively.

Preparations and Applications of Polysaccharide Based Green Synthesized Metal Nanoparticles: A State-of-the-Art

Green chemistry is the torch bearing field of sustainable research where without use of any toxic chemicals, environment-friendly metal nanoparticles are produced. Advantages of green nanoparticle synthesis over chemical-based synthesis are its nearly zero toxicity with wider applications. As the multidrug resistant species begin to emerge, green synthesized nanoparticles have been arisen as a potent alternative of antimicrobials along with various other applications in diverse fields. The main hindrances behind green synthesis are choice of material and its availability. Because of cheaper cost, wide availability, enhanced effectivity and fewer side effects, polysaccharides have successfully replaced the position of chemical reducing agents in nanoparticle synthesis. Our present review focuses on preparation and applications of polysaccharide based metal nanoparticles; a state-of-the-art research with special emphasis on green synthesized silver nanoparticles as a potent source of emerging antimicrobial.

Silver Nanoparticles Mediated by Costus afer Leaf Extract: Synthesis, Antibacterial, Antioxidant and Electrochemical Properties.

Synthesis of metallic and semiconductor nanoparticles through physical and chemical routes has been extensively reported. However, green synthesized metal nanoparticles are currently in the limelight due to the simplicity, cost-effectiveness and eco-friendliness of their synthesis. This study explored the use of aqueous leaf extract of Costus afer in the synthesis of silver nanoparticles (CA-AgNPs). The optical and structural properties of the resulting silver nanoparticles were studied using UV-visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infra–red spectrophotometer (FTIR). TEM images of the silver nanoparticles confirmed the existence of monodispersed spherical nanoparticles with a mean size of 20 nm. The FTIR spectra affirmed the presence of phytochemicals from the Costus afer leaf extract on the surface of the silver nanoparticles. The electrochemical characterization of a CA-AgNPs/multiwalled carbon nanotubes (MWCNT)-modified electrode was carried out to confirm the charge transfer properties of the nanocomposites. The comparative study showed that the CA-AgNPs/MWCNT-modified electrode demonstrated faster charge transport behaviour. The anodic current density of the electrodes in Fe(CN)6]4−/[Fe(CN)6]3− redox probe follows the order: GCE/CA-Ag/MWCNT (550 mA/cm2) > GCE/MWCNT (270 mA/cm2) > GCE (80 mA/cm2) > GCE/CA-Ag (7.93 mA/cm2). The silver nanoparticles were evaluated for their antibacterial properties against Gram negative (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa) and Gram positive (Bacillus subtilis and Staphylococcus aureus) pathogens. The nanoparticles exhibited better inhibition of the bacterial strains compared to the precursors (leaf extract of Costus afer and silver nitrate). Furthermore, the ability of the nanoparticles to scavenge DPPH radicals at different concentrations was studied using the DPPH radical scavenging assay and compared to that of the leaf extract and ascorbic acid. The nanoparticles were better DPPH scavengers compared to the leaf extract and their antioxidant properties compared favorably the antioxidant results of ascorbic acid. The green approach to nanoparticles synthesis carried out in this research work is simple, non-polluting, inexpensive and non-hazardous.