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One pot phytosynthesis of gold nanoparticles using Genipa americana fruit extract and its biological applications
Abstract
In this article, rapid one pot synthesis of gold nanoparticles (GNPs) using an eco-friendly extract of Genipa americana L. fruit is described. Electrospray ionization mass spectrometry (ESI-MS) and Fourier transform infrared (FTIR) spectroscopic studies demonstrated that small molecules such as genipin, genipaol, geniposide and ranolazine can act as reducer as well as stabilizers. The monodispersed, spherical GNPs were further characterized by UV–vis spectroscopy at λmax = 535 nm, transmission electron microscopy (TEM), dynamic light scattering (DLS) and X-ray diffraction (XRD) analysis. This synthetic approach offers a greener and alternate route to the preparation of GNPs free from toxic chemical components and stable for 6–7 months under room temperature. The green synthesized GNPs showed weak antioxidant efficacy against 1, 1-diphenyl-2- picrylhydrazyl and no cytotoxicity against A-549 and HeLa human cancer cell lines, from lung and cervix. This study opens a new industrial scope of G. americana fruit in nanoscience and as surface modified GNPs can be developed into a successful drug carrier for future pharmaceutical products.
... The broad spectrum slope of 300 to 600 nm ( Figure 3a) corresponds to the constituents of beepollen such as, flavonoids, amino acids, sugar, fatty acids, etc [29]. After synthesis, the UV-visible spectrum showed a new absorption peak at λmax 530 nm (Figure 3b) corresponding to the SPR of AuNPs, and confirm that spherical AuNPs are formed [30,31]. Therefore, the light magenta colour in the reaction mixture is associated with the reduction of Au 3+ to Au 0 (Au 3+ + 3e -→ Au 0 ) by the bee pollen constituents and formation of AuNPs. ...
... Few AuNPs are triangular and bigger than spherical particles. The concentric ring of the SAED patterns (Figure 5c) indicated that these AuNPs were predominantly spherical, (111) orientation, polycrystalline, and formed by the reduction of metallic ions [15,18,30]. The DLS analysis confirmed the size distribution and polydispersity index (PDI) of AuNPs in the aqueous medium (Figure 5d). ...
... It can also be noticed that the peak corresponding to the (111) plane is stronger than the other planes, suggesting that (111) is the dominant orientation, as evidenced by the TEM-SAED image(Figure 5c). The XRD results are consistent with various reported values, confirming the cubic structure of phytosynthesized AuNPs[6,21,30,31]. ...
Nowadays, the exploration of natural materials for the production of nanoparticles is of special interest due to its ecofriendly nature. In this paper, we presented the biosynthesis of gold nanoparticles (AuNPs) in a green route by using water extract of pollen from Andean honeybees. Furthermore, AuNPs have been characterized by various techniques and tested for the catalytic reduction of 4-nitrophenol (4-NP). The biosynthesized AuNPs were analyzed using UV-vis spectroscopy, Transmission electron microscopy (TEM), Dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) spectroscopy to confirm their optical properties, stability, surface morphology, and purity. The synthesized AuNPs proved to be well dispersed, spherical, and triangular in shape, with particle sizes ranging from 7 to 42 nm having λmax at 530 nm. Moreover, FTIR suggests the capping of AuNPs with pollen constituents and XRD confirms the crystalline structure of AuNPs. Additionally, prepared AuNPs were demonstrated to be effective in reducing organic pollutant 4-NP to 4-aminophenol (k = 59.17898 x 10-3 min-1, R2 = 0.994). All of these studies have emphasized that AuNPs production can be scale up by using naturally available pollen grains and open up a new perspective for beekeepers.
... Over the last few years, a variety of plant materials such as Dracocephalum kotschyi [6], Costus pictus [26], Sesbania grandiflora leaf [8], Maytenus royleanus stem [1], Commelina nudiflora edible weed [24], Gnidia glauca flower [11], fruit of Punica granatum [25], Genipa americana [18], Prunus domestica [9], banana [10], Coffea arabica [5], Lantana camara [19], Couroupita guianensis [30], Artocarpus heterophyllus [4], and peel of Nephelium lappaceum [23] have been already reported for the green synthesis of AuNPs. ...
... Antioxidant activity in CF-AuNPs was measured by using DPPH as the free radical model and an adapted method by Kumar et al. [18]. An aliquot (500 μL) or control and 500 μL of H 2 O were mixed with 2.0 mL of 0.2 mM DPPH· in 96% ethanol. ...
... In Fig. 1b, the CF extract shows bands at 250-350 nm resulting from the n-π* electronic transition in the biomolecules of the CF extract such as sugars, flavonoids, tannins, hydroxycinnamic acid, and anthocyanins [17,28]. It was suggested that the phytochemicals contained in CF extract help to reduce Au 3+ ions to Au(0) particles and act as a bioreducer as well as a stabilizing agent to finally produce CF-AuNPs [18,22]. ...
In this study, gold nanoparticles (CF-AuNPs) were efficiently prepared from aqueous extracts of ripened Capuli (Prunus serotina Ehrh. var. Capuli) fruit by reduction of Au³⁺ and characterized by a variety of instrumental analyses. A noticeable change in color to ruby red/purple was observed during the formation and stabilization of CF-AuNPs. The UV–Vis spectroscopy has proven the characteristic absorption peaks λmax 544 nm and 934 nm of CF-AuNPs. The biosynthesized CF-AuNPs were spherical and triangular shape confirmed through TEM analysis. The average size of the different CF-AuNPs observed during the DLS and TEM analysis ranged from 30 to 400 nm. The partial crystallinity of CF-AuNPs and their surface binded with phytochemicals is evident from the XRD patterns. Furthermore, synthesized CF-AuNPs have also been applied for antioxidant and photocatalytic applications. This work covers the fundamental principals of green chemistry and joins hands for environmental protection through nanoscience.
Graphical abstract
... In the case of AuNPs synthesized using fruit extract from Genipa americana, substances such as genipin, genipaol, geniposide and ranolazine acted as reductants of gold ions. During AuNP synthesis using the extract of Lycopersicon esculentum, citric and ascorbic acids also had the ability to reduce gold ions [61,62]. Table 1. ...
... Fruit; water extract [47] Anthocyanins Punica granatum Fruit; water extract [48] Cholidonic, superbine, colchicine, gloriosol, phytosterils and stigmasterin Gloriosa superba Leaf; water extract [49] Pectins, ribose, phenolic compounds Papaver somniferum Leaf; methanol extract [52] Amino acids, phenolic compounds, flavonoids Artemisia capillaris Whole plant; water extract [53,54] Glutanic acid, asparagine, leucine, lysine, glycine, alanine Galaxaura elongata Whole plant; water extract [55,56] Tannins Black tea Leaf; ethanol extract [57] Phenolic compounds Medinilla speciosa Fruit; water extract [36] Catechins, ascorbic acid Mimosa tenuiflora Tree bark; water/ethanol extract [10] Estragole, linalool, carvacral, urosalic acid, cirsimarin, rosmarinic acid Ocinum sanctum Flower and leaf; water extract [60] Genipin, genipol, geniposide, ronolazine Genipa americana Fruit; water extract [61] Citric and ascorbic acid Lycopersicon esculentum Fruit; water extract [62] Pectins ...
Recently, the biosynthesis of gold nanoparticles (AuNPs) has been widely studied and described. In the age of bacterial drug resistance, an intensive search for new agents with antibacterial properties or a new form of antibiotics with effective action is necessary. As a result, the antibacterial activity of AuNPs functionalized with natural compounds is being investigated more frequently. AuNPs biosynthesized with plant extract or functionalized with bioactive compounds isolated from plants could be particularly useful for pharmaceutical applications. The biosynthesized AuNPs are stabilized by an envelope, which may consist of flavonoids, phenolic acids, lipids and proteins as well as carbohydrates and vitamins. The composition of the natural coating affects the size, shape and stability of the AuNPs and is also responsible for interactions with the bacterial cell wall. Recently, several mechanisms of AuNP interactions with bacterial cells have been identified. Nevertheless, they are not yet well understood, due to the large diversity of plants and biosynthesized AuNPs. Understanding the antibacterial mechanisms allows for the creation of pharmaceutical formulations in the most useful form. Utilizing AuNPs functionalized with plant compounds as antibacterial agents is still a new concept. However, the unique physicochemical and biological properties of AuNPs emphasises their potential for a broad range of applications in the future.
... Genipa americana L. belongs to the Rubiaceae family and is popularly known as Jenipapeiro, being distributed along the Brazilian coast and Atlantic Forest. It can also be found in South and Central America, Africa and Asia (Ueda et al., 1991;Kumar et al., 2016). The evaluation of the chemotaxonomic profile of the plant family showed the presence of glycosylated iridoids in several species, leading to the conclusion that these metabolites are probably present in most subfamilies of Rubiaceae (Hiroyuki et al., 1988). ...
Genipa americana L. is a plant native to the Americas, popularly known in Brazil as Jenipapeiro, and is chemically characterized by the presence of genipin, which has pharmacological actions such as anti-inflammatory and antioxidant. The bark is used for its antiulcerogenic and antidiarrheal activities. Research developed for chemical knowledge have shown the plant is of interest for the production of efficient drugs such as antioxidants and antimicrobials. Free-living parasites, including those of the genus Acanthamoeba, have aroused interest and the study of plants used in folk medicine is a strategy for the discovery of conventional treatments to the infections caused by this parasite to be used pure or in preparations such as microemulsions (ME), which offer advantages related to the release of drugs and the absorption of the active ingredient. The aim of the study was to evaluate antiparasitic and antioxidant activities as well as to obtain a ME from the hydroethanolic extract (HEE) of G. americana. The DPPH free radical reduction method was used to evaluate the antioxidant activity of HEE, which showed an inhibition percentage (PI) of 47.82%. The antiparasitic activity of the HEE using A. castellanii trophozoites showed a PI of 80% at the highest concentration tested (9 mg mL-1). The ME containing 10% HEE was characterized for its droplet size (18.33 µm), pH (5.68) and polydispersity index (0.19). Therefore, the HEE presented antioxidant and antiparasitic effects, while its microemulsion showed potential to disperse particles.
... Both evidenced similar spectra, which would indicate the presence of biomolecules at the NPs' surface, which controlled the NPs' agglomeration. This behavior has been also observed in previous studies, where it was attributed to green synthesis using plant extracts [26]. Deeper studies in the identification of the biomolecules involved in the reduction process are required, and our research group is already working on this fascinating topic. ...
Herein, the green synthesis of silver nanoparticles (AgNPs), assisted by LED light, using the aqueous extracts of agroindustrial waste products, such as avocado seeds (ASs), cocoa pod husks (CPHs), and orange peels (OPs), is presented. Surface plasmon resonance analysis showed faster and complete NP formation when irradiated with blue LED light. Green and red light irradiation showed non- and limited nanoparticle formation. TEM analyses confirmed the semispherical morphology of the synthesized AgNPs, with the exception of OP–AgNPs, which showed agglomeration during the light irradiation. For AS–AgNPs and CPH–AgNPs, the average particle diameter was about 15 nm. Interestingly, the CPH extract demonstrated faster nanoparticle formation as compared to the AS extract (100 min vs. 250 min irradiation time, respectively). FTIR spectroscopy assessed the involvement of diverse functional groups of the bioactive phytochemicals present in the plant extracts during nanoparticle photobiosynthesis. The antioxidant activity, as determined by ferric reducing antioxidant power (FRAP) assay, varied from 1323.72 µmol TE/mL in the AS aqueous extract to 836.50 µmol TE/mL in the CPH aqueous extract. The total polyphenol content was determined according to the Folin–Ciocalteu procedure; the AS aqueous extract exhibited a higher polyphenol content (1.54 mg GAE/g) than did the CPH aqueous extract (0.948 mg GAE/g). In vitro antibacterial assays revealed that the AS–AgNPs exhibited promising antibacterial properties against pathogenic bacteria (E. Coli), whereas the CPH–AgNPs showed antibacterial activity against S. aureus and E. coli. The green synthesis of AgNPs using AS, CPH, and OP aqueous extracts reported in this work is environmentally friendly and cost-effective, and it paves the way for future studies related to agroindustrial waste valorization for the production of advanced nanomaterials, such as antibacterial AgNPs, for potential biomedical, industrial, and environmental applications.
... Au-NPs have been widely studied and applied in the field of tumor diagnosis and treatment because of their special fundamental properties. The plant extract-mediated synthesis of the Au-NPs has been reported for human wellness; applications of Au-NPs include as anticancer [9,10,11], and antioxidant [12,13]. For therapeutic cancer, there is a need to develop a new planned drug. ...
... Another Brazilian fruit recently studied, but which did not show antioxidant and antitumor action on a LC cell line A-549, was genipap (Genipa americana) (B. Kumar et al., 2016). Similarly to other case studies discussed above, the lack of bioactivity of genipap samples may be due to an inadequate administered dose (0.01-20 μM). ...
Lung Cancer (LC) is an emergent disease widespread globally. Compared to other types of cancer, LC has one of the lowest survival rates (18%). As some risk factors associated with the development of lung carcinogenesis are still unavoidable, researchers have been trying to find efficient and safe alternatives that can help prevent LC or even attenuate its rapid evolution after diagnosis. Studies with natural products promise to offer biological effects against several types of cancers, including LC. The uncountable types of plant matrices dispersed in nature, or even their extracts, contain a powerful composition of bioactive compounds with promising biological effects on LC. The biomes in Brazil are examples of regions with a great biodiversity of bioactive compounds-rich fruits. Therefore, this review aimed to present the potential anticancer effect of Brazilian native fruits, their fractions, and by-products on LC through the elucidation of the main molecular mechanisms involved. The Brazilian plant matrices discussed here (açaí, achiote, araticum, camu camu, cocoa, jaboticaba, genipap, guarana, and pequi) showed promising evidence by inducing cellular apoptosis, reducing cancer cell viability and tumor growth, and regulating cell cycle.
... We found that the XRD patterns of mixed and separated nanofibers were wider than pure PCL, which indicated the smaller the particles, the broader the diffraction peak. 36 Regardless, in mixed or separated nanofibers, the peak intensities of the cross-linked membranes were shorter than the fresh membranes. We hypothesized that the surface crystalline structures were destroyed by cross-linking agents. ...
Purpose:
A promising vascular scaffold must possess satisfying mechanical properties, great hemocompatibility, and favorable tissue regeneration. Combining natural with synthetic materials is a popular method of creating/enhancing such scaffolds. However, the effect of additional modification on the materials requires further exploration.
Materials and methods:
We selected polycaprolactone (PCL), which has excellent mechanical properties and biocompatibility and can be combined with collagen. Electrospun fibers created using a PCL/collagen solution were used to fashion mixed nanofibers, while separate syringes of PCL and collagen were used to create separated nanofibers, resulting in different pore sizes. Mixed and separated nanofibers were cross-linked with glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), and genipin; hence, we named them as mixed GA, mixed EDC (ME), mixed genipin (MG), separated GA, separated EDC (SE), and separated genipin (SG).
Results:
Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction showed that cross-linking did not affect the main functional groups of fibers in all groups. ME, MG, SE, and SG met the requisite mechanical properties, and they also resisted collagenase degradation. In hemocompatibility assays, only ME and MG demonstrated ideal safety. Furthermore, ME and MG presented the greatest cytocompatibility. For vascular scaffolds, rapid endothelialization helps to prevent thrombosis. According to human umbilical vein endothelial cell migration on different nanofibers, ME and MG are also successful in promoting cell migration.
Conclusion:
ME and MG may be promising candidates for vascular tissue engineering. The study suggests that collagen cross-linked by EDC/N-hydroxysuccinimide or genipin facilitates endothelial cell regeneration, which could be of great benefit in tissue engineering of vascular scaffolds.
... The gold nanoparticles using the green chemistry approach include various techniques like microwaveassisted synthesis, [15] one-pot synthesis, [16] facile one-step synthesis, [14] , etc. In recent years, bacteria, fungi, yeast and algae have also been used to synthesize nanoparticles. ...
Due to the wide range of applications in the field of medicine, gold nanoparticles are the most promising agents in nanotechnology with a variety of physical, chemical, optical, and mechanical properties. Researchers have been interested in the green synthesis of gold nanoparticles in recent years because of their wide range of applications and low toxicity. The synthesis of gold nanoparticles using plant-mediated extracts has shown the fastest reduction due to the presence of phytoconstituents like phenolic compounds, flavonoids, alkaloids, terpenoids, polyphenols, polysaccharides, etc. Proteins, vitamins, and minerals are included in the extracts and act as stabilizing and capping agents. Gold nanoparticles are made from plant extracts and are of natural origin; they are thought to be safer for biomedical uses. In this review, we elaborate on the plant-mediated biosynthesis of gold nanoparticles and their biological applications, emphasizing cancer therapeutics.
... In many cases, the synthesised AuNPs by fruit extract, the SPR band position was in the wavelengths range that corresponds to large and small spheres (Timoszyk, 2018). Those AuNPs were synthesised by fruit extract of Dillenia indica (Xin Lee et al., 2016), blueberry (Nadagouda et al., 2014), pomegranate (Nadagouda et al., 2014), grape (Krishnaswamy et al., 2014), Mangifera indica (Yang et al., 2014), gooseberry (Ankamwar et al., 2005), Prunus domestica (Dauthal and Mukhopadhyay, 2012), Garcinia kola (Akintelu et al., 2020), Bael, Eugenia jambolana, and Soursop (Vijayakumar, 2019), Garcinia mangostana (Xin Lee et al., 2016), Litsea cubeba (Doan et al., 2020), pineapple (Ghafoor et al., 2020), Citrus lemon, Citrus reticulate, Citrus sinensis and Citrus lanatus (Baek and Patra, 2015;Sujitha and Kannan, 2013), Terminalia bellirica (Annavaram et al., 2017), Artocarpus heterophyllus (Basavegowda et al., 2015), Coffea arabica (Kumar et al., 2017), Genipa Americana (Kumar et al., 2016), Nitraria schoberi (Rad et al., 2013), Punica gratanum (Ahmad, 2012) and Ziziphus jujube (Kirubha and Alagumuthu, 2014). The other shape observed in the synthesis of AuNPs from blackberry (Nadagouda et al., 2014), M. Calabura (Kumar et al., 2018), Tansy (Dubey et al., 2010), Cornus mas L (Perde-Schrepler et al., 2016), Ciuraupitia guianensis (Aubl.) ...
Nanotechnology is a promising field that has gained interest because of its broad spectrum of applications. Nanotechnology is the precisely tampering of substances on the nanoscale (1 nm-100 nm). Among the nanoparticles of the noble metals, gold has gained interest due to its unique properties. There are various methods to synthesize the gold nanoparticles for instance, physical, chemical and green method; with the green method being easy, effective, cheapest, eco-friendly and non-toxic. This method has a major potential to boost large production without using toxic chemicals. Gold nanoparticles are easily synthesised by using plant extract and characterised by several techniques like scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and atomic force microscopy (AFM) for the morphology. Size and shape play a crucial role in nanoparticle applications. Some factors affect the synthesis and also effects on size and shape of nanoparticles. The current article aims to review the AuNPs synthesis with different fruits extract and their by-products. Reactions condition involved during synthesis, the concentration of precursor salt and volume of extract used, shape and morphology of resulting nanoparticles and techniques used for characterisation are also discussed.
... For example, using leaf extracts from Hippophae rhamnoides, Gardenia, and Henna to synthesize Fe NPs does not need toxic chemical reagents, and high reaction energy and temperature (Naseem and Farrukh, 2015;. At present, there are already some extraction methods that are performed at low energy, such as reaction temperature lower than 100 • C for the synthesis of Ag NPs using grape seed extract (Ping et al., 2018), or 22 and 25 • C in the synthesis of Au NPs using Genipa americana fruit extract (Kumar et al., 2016a). Likewise, when Nettle and Thyme leaf extracts were used to synthesize Fe NPs, the required temperature was 80 • C . ...
Nanoscale metals are widely used in many fields such as environment, medicine, and engineering that synthesis of nanoscale metals is a timely topic. At present, nanoscale metals are mainly synthesized by chemical methods that have unintended effects such as environmental pollution, large energy consumption, and potential health problems. In response to these challenges, green synthesis, which uses plant extracts instead of industrial chemical agents to reduce metal ions, has been developed. Green synthesis is more beneficial than traditional chemical synthesis because it costs less, decreases pollution, and improves environmental and human health safety. In this review, current developments in the green synthesis of nanoparticles of gold (Au NPs), silver (Ag NPs), palladium (Pd NPs), copper (Cu NPs), and iron and its oxide (Fe NPs) were evaluated. Major findings reveal the complexity in geographical and seasonal distributions of plants and their compositions that green synthesis is limited by time and place of production as well as issues with low purity and poor yield. However, considering current environmental problems and pollution associated with chemical synthesis, green synthesis offers alternative development prospects and potential applications.
... Pentagonal and triangular shaped biosynthesized AuNPs with sizes ranged between 10-50 nm showed substantial anticancer potential against cervical cancer cell lines HeLa by inhibiting their proliferation with an IC 50 value of 100 µg/mL [132]. Other studies against cervical cancer using HeLa cell lines demonstrated the inhibitory activities of biosynthesized AuNPs derived from various plant extracts, their sizes and IC 50 values varied and were dependent upon the type and dose of respective plant extracts used [133][134][135][136]. Moreover, cytotoxicity testing of biosynthesized AuNPs has been conducted on various other cell lines such as kidney [122,137,138], leukemia [139], and liver [140], as mentioned in Table 2. Available data regarding anticancer activities of biosynthesized AuNPs against the cell lines mentioned above for cervical cancer, breast cancer, lung cancer, kidney cancer, leukemia and liver cancer are summarized in Table 2 with their citations. ...
Cancer is one of the foremost causes of death worldwide. Cancer develops because of mutation in genes that regulate normal cell cycle and cell division, thereby resulting in uncontrolled division and proliferation of cells. Various drugs have been used to treat cancer thus far; however, conventional chemotherapeutic drugs have lower bioavailability, rapid renal clearance, unequal delivery, and severe side effects. In the recent years, nanotechnology has flourished rapidly and has a multitude of applications in the biomedical field. Bio-mediated nanoparticles (NPs) are cost effective, safe, and biocompatible and have got substantial attention from researchers around the globe. Due to their safe profile and fewer side effects, these nanoscale materials offer a promising cure for cancer. Currently, various metallic NPs have been designed to cure or diagnose cancer; among these, silver (Ag), gold (Au), zinc (Zn) and copper (Cu) are the leading anti-cancer NPs. The anticancer potential of these NPs is attributed to the production of reactive oxygen species (ROS) in cellular compartments that eventually leads to activation of autophagic, apoptotic and necrotic death pathways. In this review, we summarized the recent advancements in the biosynthesis of Ag, Au, Zn and Cu NPs with emphasis on their mechanism of action. Moreover, nanotoxicity, as well as the future prospects and opportunities of nano-therapeutics, are also highlighted.
... The obtained results were compared with Trolox (70 μmol/L). For scavenging activity, DPPH radical was dissolved in ethanol and used as a blank 31 www.nature.com/scientificreports/ Scavenging activity percentage was calculated with Eq. (1) where A sample is the sample absorbance and A control is the blank absorbance. ...
In this work we use Mimosa tenuiflora (MtE) extracts as reducing agents to synthesize silver nanoparticles (AgMt NPs) which were characterized by DPPH and Total Polyphenols Assays, UV-visible, X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Thermogravimetric analysis (TGA). AgMt NPs possess average sizes of 21 nm and fcc crystalline structure, it was also confirmed that the MtE is present in the AgMt NPs even after the cleaning protocol applied. Subsequently, carbopol hydrogels were made and the MtE and the synthesized AgMt NPs were dispersed in different gels (MtE-G and AgMt NPs-G, respectively) at 100 µg/g concentration. The gels were characterized by UV-Vis, IR, and rheology. Antimicrobial tests were performed using Staphylococcus aureus and Escherichia coli. Burn wound healing was evaluated in a second-degree burn injury on a Wistar rats model for 14 days and additional skin biopsies were examined with histopathological analysis. Gel with commercial silver nanoparticles (Ag NPs) was prepared and employed as a control on the biological assays. Hydrogel system containing silver nanoparticles synthesized with Mimosa tenuiflora (AgMt NPs-G) is a promising therapeutic strategy for burn wound healing, this due to bactericidal and anti-inflammatory effects, which promotes a more effective recovery (in percentage terms) by damaged area.
... The peak formed at 1648.15 and 1449.25 cm À1 correspond to aldehydic stretching vibrations of methyl acetate or conjugated carboxyl and C ¼ C stretching. The peaks at 1119.31 and 1071.90 cm À1 are due to sugar absorption related to alcoholic group of the C-O-C and CH 2 OH deformation of -OH in phytoconstituents [25]. The bands at 3315. ...
The present study encompasses green synthesis of silver nanoparticles (AgNPs) using aqueous leaf extract of Arabian Primrose within 6 min of reaction at 60 °C, pH 7 and their characterisation using physico-chemical analytical techniques. UV-Visible spectroscopy elucidated the surface plasmon resonance around 420 nm. FESEM and TEM images revealed that AgNPs were spherical with average diameter 10-60 nm. XRD pattern confirmed their crystalline nature. The leaf extract rich in phenolics and flavonoids was subjected to GC-MS analysis that identified bioactive compounds helping in reduction and stabilisation of AgNPs. The synthesised AgNPs possessed high anti-oxidant potential against DPPH and H2O2 radicals. Incidentally, the AgNPs acted as excellent nanocatalyst towards borohydride reduction and degradation of structurally different organic dyes. The AgNPs also exhibited selective colorimetric sensing of hazardous mercuric, ferric ions and ammonia. Such AgNPs were cytotoxic against HeLa cells (IC50 7.18 µg/mL) and compatible towards normal L20B cells. These AgNPs showed effective anti-microbial activity against different human pathogens tested (bacterial and fungal). This is probably the first report of AgNPs synthesis using Arabian Primrose leaf extract showing strong anti-oxidant, catalytic, biosensing, anti-cancer and anti-microbial activities and find remarkable applications in medical, industrial and ecological sectors.
... Many plant extracts can be employed for metal nanoparticle synthesis. These extracts can be used as a metal ion reducing agent or stabilising and coating agents for synthesising nanoparticles [2,3]. Toxicity and safety of metal nanoparticles toward the environment and humans are a crucial factor for biomedical application. ...
Gold nanoparticles (AuNPs) have been introduced for increasing the effectiveness of various cancer treatments such as radiation and photodynamic therapy. Instead of toxic chemicals, various natural compounds have been introduced for AuNPs synthesis. Here, gallic acid-coated AuNPs (Ga@AuNPs) with the average diameter of 17.9 ± 10 nm and surface charge of −16.2 ± 3.2 mV have been synthesised through easy and single-step chemical route and were characterised with transmission electron microscopy (TEM), dynamic light scattering (DLS) and UV–Vis spectroscopy. The interaction of Ga@AuNPs and methylene blue (MB) photosensitisers was confirmed through various techniques such as FTIR spectroscopy, zeta potential investigation, and UV–vis spectroscopy. Based on our results, methylene blue was adsorbed to the surface of Ga@AuNPs through various amine and thiol functional groups. Upon laser radiation, a release of singlet oxygen species (ROS) from nanoformulation of methylene blue was more gradual than free methylene blue based on the determination of singlet oxygen in the present of 1,3-diphenylisobenzofuran (DPBF) radical scavenger. The Ga@AuNPs nanoparticles were not representing significant toxic effects toward cells. However, the synthesised nanoparticles could increase the effectiveness of radiation therapy or combined treatment of methylene blue mediated photodynamic and radiation therapy in an in-vitro investigation.
... Many research papers have reported on plant-mediated biosynthesis of metal nanoparticles. For AuNP synthesis, various plant extracts such as Olea europaea [15], Ipomoea carnea [16], Salix alba [17], Genipa americana [18], Dalbergia coromandeliana [19], Piper longum [20], Eucommia ulmoides bark [21], Butea monosperma [22], Momordica charatia [23], and Lagerstroemia speciosa [24] have been proposed. Polyphenolic, terpenoids, alkaloids, and sugars have been reported as being very well-known functional groups responsible for metal reducibility and nanoparticle stability [25]. ...
A green, simple, and rapid synthesis of gold nanoparticles using plant extract, Cryptolepis buchanani Roem. and Schult, and their applications are first described in this paper. The formation of gold nanoparticles was visually observed by the appearance of a ruby red color, which was further indicated by an absorption peak at 530 nm in UV-Vis spectroscopy. Optimization of reaction parameters for the gold nanoparticles was also investigated. Various analytical techniques were employed as part of the process of characterizing the resulting gold nanoparticles. Fourier transform infrared (FTIR) analysis revealed that the phenol compounds present in the extract were responsible for gold(III) reduction and stabilization of gold nanoparticles. Transmission electron microscopy (TEM) analysis showed that the gold nanoparticles were spherical in shape with an average diameter of 11 nm. Powder X-ray diffraction (XRD) pattern indicated that the green synthesis approach produced highly crystalline, face-centered cubic gold nanoparticles. Energy-dispersive X-ray spectroscopy (EDS) measurements confirmed the presence of elemental gold in the prepared nanoparticles. The negative zeta potential value of gold nanoparticles was found to be -30.28 mV. The green synthesized gold nanoparticles expressed effective antibacterial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Acinetobacter baumannii and exhibited an excellent catalytic property in terms of its reduction ability of methylene blue.
... Literature contains abundant reports to the preparation of gold nanomaterials that may pose a risk, which might be adsorption of organic solvents, polymers, ligands, zeolites, and surfactants [15][16][17][18]. Therefore, various researchers used plants, seeds, leaves, flowers, bacteria, yeast, etc. to the synthesis of monometallic and bimetallic nanomaterials of gold [19,20]. Shingaravelu et al. were used flower of couroptia guianesis flowers to the fabrication of gold NPs. ...
Cyanidin 3,5-di-O-glucoside anthocyanin was extracted from red rose flower petals and used as reducing and capping agent for the green synthesis of anisotropic gold nanoparticles (Au NPs). Transmission electron microscope (TEM) images indicated that the Au NPs have large number of small spheres of gold. Surface plasmon resonance band position strongly depended on the [HAuCl4] and [anthocyanin]. Cationic surfactant distinctly changed the shape, size, number of NPs, and size distribution of Au nanodisks at room temperature. Conventional techniques were used to the estimate the antiradical and antimicrobial activities of the cyanidin 3,5-di-O-glucoside anthocyanin and gold NPs. The 2,2-diphenyl-l-picrylhydrazyl nitrogen radical (DPPH·), two bacteria strains (Staphylococcus aureus and Escherichia coli), and two yeast strains (Candida albicans ATCC 10231 and Candida parapsilosis ATCC 22019) were used to determine the antioxidant and antimicrobial properties of CTAB-capped gold NPs. Eosin yellow photocatalytic degradation followed apparent first-order kinetics with activation energies of 54.4 kJ/mol and 39.5 kJ/mol, respectively, for oxidative and sunlight catalyzed paths. The photocatalytic rates drastically inhibited with scavengers, demonstrating that the reactive radical oxygen species (HO· and O2−·), holes (h+) and electrons (e−) played major role in the degradation.
... During the formation of nanoparticles, biomolecules present in the plant extracts can act as capping agents and https://doi.org/10.1016/j.jddst.2020.101516 Received 9 October 2019; Received in revised form 15 December 2019; Accepted 9 January 2020 stabilize the formed nanoparticles [10]. Presence of such molecules can be detected by techniques such as Fourier transform infrared spectroscopy (FTIR), Proton nuclear magnetic resonance ( 1 H NMR) spectroscopy and other spectroscopic approaches. ...
Various applications of nanotechnology in healthcare, agriculture, environmental and other technological fields have considerably transformed human life. However, harmful effects of nanomaterials synthesized by traditional methods reduce the potential of the instantaneous application of nanotechnology-based products in healthcare field. Application of plant extracts as reducing agents minimizes the use of hazardous chemicals to produce nanomaterials. Phytonanoparticles are relatively biocompatible for biological applications due to the lack of traces of harmful chemicals in them. The specific plant or plant part used for the synthesis process plays pivotal role as it influences the properties of resultant nanoparticles. Phytonanoparticles can generally be used as antimicrobial agents in blood bags, wound dressings, dental implants and other biomedical devices. They are also extensively studied for their potential applications in cancer detection and therapy. In this review, we discuss about various biomedical applications of phytonanoparticles which are synthesized using plant parts such as shoots, leaves, fruits and roots of different plant species.
Gold nanoparticles (AuNPs) have been applied in a variety of fields based on their unique physical and chemical properties. Phenolic compounds (PCs) are the largest variety of phytochemicals in foods and have received substantial attention owing to their extraordinary health benefits. Recently, extensive studies have been conducted on the synthesis and conjugation of PCs onto AuNPs (AuNP/PC) characterization, their bioactivities such as antimicrobial, anti‐cancerous, anti‐inflammatory. PCs served the dual roles i.e., as reductant and stabilizer during the synthesis of AuNPs/PC in a one‐pot process. The synthesis parameters for AuNP/PCs and the characteristic properties of as‐synthesized AuNP/PCs should be evaluated to achieve the highly efficient bioactivities. Therefore, the critical criteria for the synthesis of AuNP/PC such as the temperature, pH and molar ratio of the precursors are reviewed. It is found that the PCs mediated reduction of gold salt can provide the well dispersed and stable AuNPs with a high negative surface charge (‐15 to ‐54 mV) and an average SPR band ranging from 520‐600 nm. The presence of surface hydroxyl groups in AuNP/PCs was the indication of successful conjugation of PCs with AuNPs. It can be concluded that the synergistic effect of the PCs‐conjugated AuNPs greatly enhanced their bioactivities.
Book Available online at: https://www.bhumipublishing.com/books/ PREFACE We are delighted to publish our book entitled "Advances in Animal Science Volume I". This book is the compilation of esteemed articles of acknowledged experts in the fields of basic and applied animal science. This book is published in the hopes of sharing the excitement found in the study of animal science. Animal science can help us unlock the mysteries of our universe, but beyond that, conquering it can be personally satisfying. We developed this digital book with the goal of helping people achieve that feeling of accomplishment. The articles in the book have been contributed by eminent scientists, academicians. Our special thanks and appreciation goes to experts and research workers whose contributions have enriched this book. We thank our publisher Bhumi Publishing, India for taking pains in bringing out the book. Finally, we will always remain a debtor to all our well-wishers for their blessings, without which this book would not have come into existence.
Gold nanoparticles possess huge potential in various areas due to their numerous innovative features. Traditionally, nanoparticles synthesis was carried out using physical and chemical approaches. These approaches have several disadvantages, therefore the biological synthesis of nanoparticles has gained increased attention. These biological approaches utilize bacteria, viruses, algae, fungi, yeasts, and plants. Nanoparticle synthesis using plant material creates nano factories as they provide nonhazardous, clean, and environmentally friendly methods with several physicochemical properties. Gold nanoparticles have gained special consideration due to their wide range of applications. Gold has huge potential in the medical and environmental area, due to its various therapeutic activities such as antibacterial, antifungal, anticancer, and catalytic applications. Plants produce various bioactive compounds which act as reducing and capping agents, to form stable and controlled shaped gold nanoparticles. In this chapter, an overview of different reports on gold nanoparticle synthesis using plants is provided. Additionally, mechanisms involved in synthesis, factors affecting the synthesis process, and biological applications of gold nanoparticles are also discussed.
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.
Nanotechnology has attracted the attention of researchers from different scientific fields because of the escalated properties of nanomaterials compared with the properties of macromolecules. Nanomaterials can be prepared through different approaches involving physical and chemical methods. The development of nanomaterials through plant‐based green chemistry approaches is more advantageous than other methods from the perspectives of environmental safety, animal, and human health. The biomolecules and metabolites of plants act as reducing and capping agents for the synthesis of metallic green nanomaterials. Plant‐based synthesis is a preferred approach as it is not only cost‐effective, easy, safe, clean, and eco‐friendly but also provides pure nanomaterials in high yield. Since nanomaterials have antimicrobial and antioxidant potential, green nanomaterials synthesized from plants can be used for a variety of biomedical and environmental remediation applications. Past studies have focused mainly on the overall biogenic synthesis of individual or combinations of metallic nanomaterials and their oxides from different biological sources, including microorganisms and biomolecules. Moreover, from the viewpoint of biomedical applications, the literature is mainly focusing on synthetic nanomaterials. Herein, we discuss the extraction of green molecules and recent developments in the synthesis of different plant‐based metallic nanomaterials, including silver, gold, platinum, palladium, copper, zinc, iron, and carbon. Apart from the biomedical applications of metallic nanomaterials, including antimicrobial, anticancer, diagnostic, drug delivery, tissue engineering, and regenerative medicine applications, their environmental remediation potential is also discussed. Furthermore, safety concerns and safety regulations pertaining to green nanomaterials are also discussed. This article is protected by copyright. All rights reserved.
As nanopartículas (NPs) verdes são substratos naturais extraídos de recursos biológicos disponíveis na natureza. O objetivo do presente estudo foi revisar a atividade anticâncer de NPs sintetizadas a partir de extratos verdes contra células tumorais. Selecionou-se 21 artigos no banco de dados eletrônicas, PubMed e Cochrane, trabalhos publicados nos últimos 5 anos, em inglês, português e espanhol. Os resultados mostraram o potencial anticâncer das nanopartículas biogênicos contra diferentes células cancerígenas, cerca de 95% dos estudos mostram algum feito citotóxico no tumor. A linhagem das células tumorais mais estudada foi a de origem hepática, 80% dos artigos avaliaram o resultado das NPs no carcinoma hepatocelular (HepG2), e obtiveram resultados surpreendentes, a segunda linhagem de células mais estuda foi adenocarcinoma de mama (MCF-7). A citotoxicidade nas células tumorais foi avaliada através da concentração inibitória mínima (I50), e em nível molecular observou-se a presença de células apoptóticas, bem como o aumento de espécies reativas de oxigênio (ROS) intracelular e de expressões das proteínas caspases e a diminuição de enzimas anti apoptóticas. Pode-se concluir que as NPs verdes são uma alternativa eficaz no tratamento de câncer, no entanto estudos devem avaliar a atividade anticancerígena por meio de estudos in vivo em humanos.
Bioinspired synthesis of metallic nanoparticles is an eye-catching approach towards green
nanotechnology. Metallic nanoparticles and their synthesis have significantly increased, but
involvements of toxic chemicals and energy requirement limits the alternative synthesis of
nanoparticles (NPs). Whereas, a recent approach to synthesize nanoparticles from the
microorganisms and plants have evolved greatly, as most of the biological entities are
structurally similar to the nanomaterials (NMs). The NMs are very useful in various in vivo and in vitro biomedical research and applications, thus, the synthesis of those are in high demand. This chapter summarized the green synthesis of nanoparticles, its eco-friendly approach, along with antioxidant, antimicrobial, therapeutic and diagnostic applications.
The development of ecofriendly experimental methods for the fabrication of nanoparticles is emerging technique in green
chemistry and nanotechnology. In this investigation, green synthetic route was adapted to synthesize gold nanoparticles (AuNPs) using Sacha inchi leaf extract as a reducing and stabilizing agent. The green synthesized AuNPs were successfully characterized by visual, UV–visible spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM) with selected area electron diffraction (SAED), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). UV–vis spectroscopy showed a single absorbance peak at 545 nm confirming the formation of AuNPs. TEM study revealed that AuNPs were spherical in shape and size ranging from 5–30 nm. SAED, XRD and FTIR confirm the lattice pattern, crystallinity and surface property of AuNPs. Application of AuNPs as nanocatalyst was investigated in catalytic reduction of organic dye, methyl orange (>90%), where 0.113691 min−1 was the first-order kinetic constant with sodium borohydride. The as-synthesized AuNPs may be applied as nanocatalyst in the future for the treatment of organic pollutants in wastewater, efficiently. The results suggest that the adopted method is simple, inexpensive and ecofriendly for the synthesis of AuNPs and also promotes wide scope of Sacha inchi plant in the international markets.
Plant extracts mediated syntheses of gold nanoparticles (AuNPs) have earned renewed significance in recent times because it is bio-compatible, environmentally benign, simple and cost effective. The biomolecules present in the plant extract plays vital role to reduce chloroaurate ions (AuCl4−) to metallic gold (Au0) and also stabilize them in nanometric dimension. The biomolecules especially polyphenolic compounds with o-dihydroxy chelating site are highly proficient for the reduction where no additional capping agents are necessary. Plant extract mediated AuNPs also promising for their broad range of applications in the field of science and technology. In this review, we have critically discussed the green synthesis of gold nanoparticles utilizing different parts of medicinally important plants and chloroaurate ion. Phytochemicals screening of the plant extract, morphological analysis and size of the gold nanoparticles has been discussed. A possible mechanism towards the synthesis of nanoparticles, growth and their stabilization in nanoscale dimension has also explained. The catalytic, anti-microbial and anti-cancer applications of gold nanoparticles have also been described.
Cancer is a challenging healthcare problem among other health issues worldwide. Although there are several therapies used for cancer treatment, nanoimmunotherapy has attained a lot of considerations for its unique applications and hopeful future. Chemotherapy and radiotherapy are conventional therapeutic methods which are lacking particular targeting and consequent off-target effects. Because of these drawbacks, it has started searching for techniques which could widen the effectiveness of the therapy such as nanoparticles (NPs) which are mandatory. Cancer nanoimmunotherapy for immunology generates a unique and constant response against cancer by provoking the host immune system or suppressing tumour immune evasion. In cancer nanoimmunotherapy, nanoparticles are considered as potential tumour-targeting carriers such as polymers, nanoshells, dendrimers and liposomes. This chapter will highlight the current applications of nanotherapy as well as the potentiality of various NPs in cancer nanoimmunotherapy.
Nanotechnology became an unavoidable field in a wider area of research. Nanotechnology and its products give excellent results to various fields like agriculture, electronics, medicine, insecticides, pharmaceuticals, metals, large-scale industries, etc. Among nanoparticle synthesis using chemical and biological synthesis methods, biologically synthesized nanoparticles especially from plant-derived nanoparticles are currently attracting researchers and industrialists in the treatment of cancer due to their ease of availability, eco-friendliness, cost-effectiveness, and many other appealing features. Even though the biologically synthesized nanoparticles exhibited a significant result, major concerns toward their biocompatibility, safety, and regulatory aspects are currently under exploration, since the activity of nanoparticles varies with their size, shape, and attachments to other functional groups. The present review was carried out to discuss in detail the management, biocompatibility, safety, and regulatory aspects of nanoparticles involved in the evaluation of anticancer studies.
Natural products have widely been used in applications ranging from antibacterial, antiviral, antifungal and various other medicinal applications. Use of these natural products was recognized way before the establishment of basic chemistry behind the disease and the chemistry of plant metabolites. After the establishment of plant chemistry various new horizons evolved, and application of the natural products breached the orthodox limitations. In one such interdisciplinary area, use of plant materials in the synthesis of nano particles (NPs) has exponentially emerged. This advancement has offered various environment friendly methods where hazardous chemicals are completely replaced by natural products in the sophisticated and hectic synthesis processes. This review is an attempt to understand the mechanism of metal nano particles synthesis using plant materials. It includes details on the role of plant's secondary metabolites in the synthesis of nano particles including the mechanism of action. In addition, use of these nano materials has widely been discussed along with the possible mechanism behind their antimicrobial and catalytic action.
Due to the innate, ecofriendly biological synthesis of metal nanoparticles, bionanotechnology has emerged as one of the most promising subjects. Gold nanomaterials have gained global attention owing to their diverse nature of applications in industry, biomedicine, and agriculture. Gold nanoparticles (AuNPs) are in high demand for their unique properties such as large surface area, surface plasmon resonance, and high dispersion. Phytonanomaterials have paved the way for a cleaner and safer environment with reduced toxicity and cost-effectiveness. Extracellular and intracellular synthesis of phytogenic nanoparticles eliminates hurdles for maintaining cultures. Plants contain an array of metabolites that act as reducing and capping agents that lead to the formation of stable metal nanoparticles. In this chapter, we explain the methods by which AuNPs can be obtained either by the use of whole plants as a living system or different plant parts, discuss the mechanisms that mediate the phytosynthesis of AuNPs, and further, highlight their potential applications.
The current commercial scenario indicates an increase in the demand for natural dyes. Compared to synthetic dyes, natural ones have the advantage of being sustainable, making them of great interest for the food and cosmetic industries. The development of new natural dyes is necessary, as well as the carrying out of complementary research regarding the existing ones.
The present study aims to characterize the physicochemical and biological characteristics of the dye obtained from dehydrated endocarp of the genipap (Genipa americana) fruit, as well as perform the relevant stability and cytotoxicity tests. The chemical characterization was performed by HPLC-MS/MS analyses. The stability studies were carried out by spectrophotometry and cytotoxicity assays using cell culture and fluorometric methods.
After dehydration and milling of the fruit endocarp, water was added to the obtained powder (in the ratio 4:1) to extract the dye. Five compounds were elucidated using HPLC-MS/MS and confirmed the presence of the geniposide as its main compound. With the X-ray diffraction and electron microscopy analysis, we characterised the obtained powder as being amorphous and of porous structure with a variable size. The thermogravimetric analysis indicated a maximum loss of 61% mass after exposure to a temperature range from 240 to 760 °C. The obtained blue dye was stable in the absence of light, at room temperature and had neutral pH. In the cytotoxicity assay, (95.0±1.3) % of viable human fibroblasts were observed after exposure to this dye. The genipap fruit can be a viable alternative to produce a natural blue dye, since it is easy to obtain and has very low toxicity in food, pharmaceutical or cosmetic products.
This study demonstrates for the first time the physicochemical and biological properties of a natural blue dye from G. americana fruit.
Multi-Drug resistant bacteria have been considered as major health problem worldwide with increasing mortality and morbidity. Recently, organic and inorganic magnetic hybrid nanoparticles exhibit the new promising activity in combating bacterial infections via different hybrid mechanisms. In the magnetic hybrid nanoparticles, magnetic nanoparticles play multiple roles, such as antibacterial agent, supporting material, magnetic separation and magnetic targeting.... This chapter explores the hybridization of magnetic nanoparticles and various nanomaterials for adapting and enhancing their antibacterial activity.
Green synthesis is an important technique for reducing the negative effects associated with the conventional methods of synthesis of nanoparticles (NPs) that are frequently run in both laboratory and manufacturing. In this chapter, we summarized the basic procedures and tools for “green” synthesis methods, especially for metal and metal oxide nanoparticles using biological extracts. This chapter provides a recent assessment of the newly collected works on metal and metal oxide nanoparticles, for example, those that include silver, gold, palladium, platinum, zinc oxide, iron, titanium, ceria, and magnetite. It also provides the current uses of the green synthesis approach through various biological extracts such as extracts of plants, fungi, bacteria, and algae. Finally, this work also discusses in brief some of the different techniques that are used for characterization of different NPs and besides studding the mechanism of work of these techniques.
Fuciodan is one of the largest polysaccharides in several medical fields, comprising a large number of applications. Gold nanoparticles (Au NPs) play an important role in the field of biomedicine. Fucoidan is considered to be the stabilizing and reducing agent for gold nanoparticles in this investigation. The RSM methodology was used as an optimization for the synthesis of Au NPs. Pure crystalline Au NPs with a medium size of 31 nm (divided between 21 and 44 nm) were formed. In-order aqueous fucoidan extracts have been used to reduce Au NP. In the NPs diffraction pattern, the X-ray diffractometer was used to show clearly that Au NPs are in FCC (Facial Centered Cubic). Fucoidane used to synthesize Au NP displays a surface plasmon resonance (SPR) peak of 555 nm. The presence of sugar molecules on the Fourier infrared spectrometer (FT-IR) has been verified. In addition, the anti-cancer activities of the Au NPs against liver-target cancer cells have been undertaken and desirable results have been obtained.
Plants are the well-known sources for the hyper-accumulation and reduction of metallic ions. Analysis of various plant extracts has justified the presence of different types of phytochemicals that possess the stabilization and reduction functionali-ties of precursors to form nanoparticles. Such characteristics make plants as an attractive source for synthesizing eco-friendly nanoparticles (NPs) with potentially less toxicity to the body. Recently, phytosynthesized nanoparticles have been explored for targeted inhibition and diagnosis of cancer cells without affecting non-cancerous healthy cells. The aim of this review is to discuss the characteristic performance of NPs synthesized from various plant sources for the diagnosis and inhibition of cancer. The mode of action of phytosynthesized nanoparticles for anti-cancer applications are also discussed.
Nanotechnology has provided advantages for the delivery of bioactive drugs, vaccines, as well as immune adjuvants, such as reduced adverse outcomes, targeted delivery of bioactive agents to immune cells, and improved therapeutic effect. In recent times, gold nanoparticles (AuNPs) have emerged as a versatile carrier system for providing more efficient delivery of therapeutics and immunotherapeutic agents. This chapter aims to discuss recent advancements in the field of AuNPs, the innovations in preparation methods of AuNPs, and allied applications. The chapter also elaborates on structural features of AuNPs and recent advancements in AuNPs-mediated delivery to improve delivery potential, as well as safety features of therapeutic agents.
The preparation of gold nanoparticles via green routes applying plant extracts as the reducing agents and stabilizers has received broad interest in the last decades. Plant-gold nanoparticles have been well-developed and applied in biochemical and medical research, but there are still challenges that must be overcome. The main challenges include the construction of chemically-robust plant-gold nanoparticles, the precise design of biomimetic surfaces to fabricate nanozymes with high catalytic activities, and the development of approaches to construct biosensors with high selectivities and sensitivities. The cores and surfaces of plant-gold nanoparticles must be considered, as well as their catalytic activities and biosensing mechanisms. This review highlights the latest achievements in plant-gold nanoparticle preparation, heterogeneous nucleation, and surface functionalization, while also focusing on their optical properties and various biological and catalytic activities. Moreover, their antioxidant and cell apoptosis mechanisms, and biological activities are described. Plant-gold nanoparticles have shown great potential in high-performance analytical assays, high-activity catalysts, effective intracellular imaging, and clinical treatment.
Nanotechnology-based application and implementation are of great interest in several research fields. Phytonanotechnology has shown great potential in precision agriculture, as nanoparticles with unique properties can be easily synthesized from different biological sources and applied in agriculture. Therefore, nanotechnology will play an important role in the development of the agricultural sector. In the coming years, hopefully new nanotechnology applications in agriculture and the food industry will be available, allowing sustainable crops and food production.
Plant diseases are major factors limiting crop production and productivity. Crops could be affected by pests and diseases, or abiotic factors that can harm a portion of the plant or the entire plant, consequently reducing the yield before it can be harvested or consumed.
Within this chapter, we address some nanotech-based tools that are able to improve the present plant protection technologies in environmentally safe conditions.
In this work, nanoparticles loaded polydimethylsiloxane (PDMS) nanocomposites were obtained by the direct reduction of Ag+ or Au3+ in ethanolic solution. Taking advantage of the colorful appearance of PDMS/Ag (yellow) and PDMS/Au (red), a colorimetric characterization was used to analyze the samples during their fabrication. For both types of samples, their colors become darker depending on the reaction time due to the increasing amount of nanosilver or nanogold formed on PDMS structures. Consequently, the collected colorimetric data expressed as ΔE ab values presented a correlation with the reaction time. For both systems, it was detected a color saturation after 24 h, indicating that this time is a critical point and the color of the samples reaches a uniformity. Simultaneously, the spectrophotometer also measured the visible spectra, and with this analysis it was possible to detect the surface plasmon resonance bands of nanosilver and nanogold at 410 and 530 nm, respectively. The nanometric nature and distributions of silver and gold nanostructures on the PDMS matrix were confirmed by transmission electron microscopy. This analysis showed that silver and gold nanostructures are small than 100 nm and exhibited different shapes.
Gold nanoparticles (Au‐NPs) have been widely used in biomedical fields such as imaging, diagnosis, and treatment because of their special characteristics. Au‐NPs can be synthesized using several methods, including the biological method, also called green or eco‐friendly synthesis. Recent studies have reported the anticancer activity of biosynthesized Au‐NPs, especially in lung cancer. This review focused on the advances in the antilung cancer activity of biosynthesized Au‐NPs and its potential mechanisms. Recent studies have reported the anticancer activity of biosynthesized gold nanoparticles (Au‐NPs), especially in lung cancer. This review focused on the advances in the antilung cancer activity of biosynthesized Au‐NPs and its potential mechanisms.
This book has been prepared to present the most representative papers that were exposed during the First International Conference of Engineering TecNM/ITToluca, to celebrate the 45th Anniversary of the Technological Institute of Toluca and the 10th Anniversary of the Master of Science in Environmental Engineering Program. Its purpose is to depict the most recent and innovative works in the different areas of Engineering, as well as some of the most outstanding scientific and technological applications. It is noteworthy that this first Conference not only constituted a discussion forum to present original contributions, but also was an opportunity for professionals and students, who have different areas of knowledge in the Engineering field, to exchange ideas and common interests. In this event, numerous and varied current issues were
addressed and the main concerns about the work in this field of knowledge were expressed. For this purpose, this book has been divided into 3 sections: i) Biobased polymers and materials, ii) Synthesis and applications of new materials, and iii) Theoretical studies. The first part presents work focused on different applications of biopolymers and their synthesized materials, such as the elimination of organic or inorganic contaminants from aqueous solutions, the synthesis of nanoparticles through organic matter and the effect of biomass, as well as the concentration of the employed acid used in its hydrolysis; mainly, these research projects are focused on reduce environmental pollution in water caused by emerging and/or biological pollutants. The second part of the book is related to the preparation of new structures; for example, the synthesis of new Carbon-based nanostructures or a new type of lead-free brass for environmental care. In this case, these compounds have been developed to reduce its environmental impact since they are kindly and not harmful with the environment. Finally, the third part of the book has been focused to some theoretical studies that complement the research on this field of knowledge, such as those that impact the investigation of artificial intelligence applied to neuronal algorithms; particularly, the benefit of this type of studies for the society is the availability of useful data in different applications, such as the mentioned previously.
The prospect of developing new approaches in the assembly of noble metal nanoparticles and its functions has been garnering intense interest among researchers in various fields. The green synthesis method is an evolving trend as it is environment benign and aids in large-scale formation of nanoparticles. The versatile properties of green synthesized gold nanoparticles (AuNPs) like surface plasmon resonance, stability and morphology are examined by UV-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), zeta potential (ZP) and high resolution transmission electron microscopy (HRTEM) studies at pH 7. Fourier transform-infrared (FT-IR) analysis confirms the pivotal role of anthocyanins and polyphenols in Fragaria ananassa (strawberry) fruit extract for the capping of AuNPs. The size of gold nanoparticles is in the range of 10 to 40 nm and they exhibit greater negative value of zeta potential. The catalytically active AuNPs follow the pseudo-first order kinetic model and takes 10 min for rapid degradation and adsorption of methylene blue dye from aqueous solution. These results confirm that Fragaria ananassa has a remarkable function in the plant-mediated synthesis of AuNPs and thus can emerge as a positive platform to convert water pollutants into harmless molecules.
This article covers the importance of Andean Ajı′/Chilli (Capsicum baccatum L.) mediated synthesis of gold nanoparticles (AuNPs), which favors for green chemistry and escape us from the use of hazardous chemicals. UV–visible spectroscopy was used to monitor the quantitative formation of AuNPs. Further, as synthesized AuNPs were characterized using Transmission electron microscopy, Dynamic Light Scattering, and X-ray diffraction. It produced spherical AuNPs at λmax = 540 nm of average size 23.9 ± 9.7 nm without any aggregation. Ajı′ extract (aq) was the good reducing and capping agent in terms of conversion to Au3+ to AuNPs. The synthesized AuNPs, also enhancing the photocatalytic degradation of methylene blue (>50%, k = 1.9585 × 10−3 min−1) under direct solar light irradiation. In addition, the experimental approach is benign, ecofriendly, and inexpensive for industrial-scale production of nanoparticles using Aji extract as natural bioreductant.
In this report, ultrasonication and Andean blackberry leaf extract is employed for the fabrication of palladium nanoparticles (PdNPs); and further evaluated its photocatalytic activity against methylene blue (MB). The as-synthesized PdNPs were characterized using UV–visible spectroscopy, transmission electron microscopy (TEM), Dynamic light scattering (DLS) and X-ray diffraction (XRD). TEM analysis demonstrated the formation of decahedron shape PdNPs with a diameter of 55-60 nm and XRD confirmed its crystalline nature. It showed photocatalytic decomposition of MB (> 72%, k = 0.002164 min-1, 10 mg/L) in an aqueous solution under solar light irradiation. From the results obtained it is suggested that ultrasound agitated aqueous leaf extract demonstrates simple, rapid, inexpensive method and should be utilized in future as green technology for the fabrication of nanoparticles.
The paper reports a simple, versatile and ecofriendly protocol for the synthesis of silver nanoparticles using the aqueous extract of Areca catechu nut and its application in catalysis and antioxidant activity. Nanoparticles of varying sizes have been synthesized at 300 K and 373 K. The synthesized nanoparticles are characterized by UV–visible spectroscopy, Transmission Electron Microscopy, X-ray diffraction analysis and Fourier Transform Infra-Red Spectroscopy. The newly formed silver nanoparticles are stable, spherical and crystalline with average particle size varying from 18.2 to 24.3 nm on changing the temperature. The phytochemicals involved in the reduction and stabilization of silver nanoparticles are identified using FTIR spectra. The synthesized silver nanoparticles show potent catalytic activity in the degradation of organic pollutants (methylene blue, Eosin-yellowish, methyl orange, and 4-nitrophenol). The catalytic activity is found to be size dependent and the degradation reaction is observed to obey pseudo-first order kinetics. Moreover, antioxidant studies on the as synthesized nanoparticles reveal efficient scavenging of the stable or harmful free radicals including DPPH, NO and OH. The catalytic and antioxidant activities of the biogenic nanoparticles would find applications in environmental and biomedical field.
Biofabrication of copper oxide nanoparticles (CuO-NPs) of a desired size remains a significant challenge. In this report, CuO-NPs were fabricated by treating 10 mM copper nitrate with Andean blackberry fruit (ABF) and leaf (ABL); and evaluated its antioxidant activity. As-prepared NPs characterization were determined by UV–visible spectrophotometry, Dynamic light scattering (DLS), Transmission electron microscopy (TEM) with selected area electron diffraction (SAED) and X-Ray Diffraction (XRD) analysis. UV–visible spectroscopy showed an electronic excitonic transition at 250 to 255 nm clearly reveals the formation of ABF and ABL CuO-NPs. DLS analysis demonstrated mean diameter of ABF CuO-NPs (43.3 nm) smaller than ABL CuO-NPs (52.5 nm). TEM with SAED confirmed the CuO-NPs are spherical and partial crystalline nature. Furthermore, the antioxidant efficacy of ABF CuO-NPs showed (89.02%, 1mM) whereas ABL CuO-NPs (75.92%, 1mM) against 1, 1-diphenyl-2- picrylhydrazyl. From the results obtained it is suggested that green CuO-NPs could be used effectively in future biomedical concerns.
Zinc oxide nanoparticles (ZnO-NPs) are known to be one of the multifunctional inorganic compounds widely used in everyday applications. This study aims to fabricate ZnO-NPs using grapefruit (Citrus paradisi) peel extract with particle size ranging from 12 to 72 nm. Structural, morphological and optical properties of the synthesized nanoparticles have been characterized by using UV–Vis spectrophotometer, TEM, DLS and FTIR analysis. They show the significant photocatalytic degradation efficiency (>56 %, 10 mg/L, 6 h) against methylene blue and antioxidant efficacy (≥80 % for 1.2 mM) against 1, 1-diphenyl-2- picrylhydrazyl. From the results obtained it is suggested that green ZnO-NPs could be used effectively in environmental safety applications and also can address future medical concerns.
Gold nanoparticles (GNPs) were prepared using four different plant extracts as reducing and stabilizing agents. The extracts were obtained from the following plants: Salvia officinalis, Lippia citriodora, Pelargonium graveolens and Punica granatum. The size distributions of the GNPs were measured using three different methods: dynamic light scattering, nanoparticle-tracking analysis and analysis of scanning electron microscopy images. The three methods yielded similar size distributions. Biocompatibility was examined by correlation of L-cell growth in the presence of different amounts of GNPs. All GNPs showed good biocompatibility and good stability for over 3 weeks. Therefore, they can be used for imaging and drug-delivery applications in the human body. High-resolution transmission electron microscopy was used to view the shapes of the larger GNPs, while infrared spectroscopy was employed to characterize the various functional groups in the organic layer that stabilize the particles. Finally, active ingredients in the plant extract that might be involved in the formation of GNPs are proposed, based on experiments with pure antioxidants that are known to exist in that plant.
Gold nanoparticles have been synthesized using
chloroauric acid and sodium dodecyl sulfate (SDS) as the surfactant
in water. These nanoparticles are analyzed using UV–vis
spectroscopic, Transmission electron microscopy and Dynamic light
scattering technique. It is spherical in shape, having a size of 50-280
nm. The result shows that SDS coated gold nanocatalyst is highly
active in the degradation of methylene blue (10 mg/L) in sunlight
(~75%) for 4.0 h.
Cervical cancer is a major cause of mortality among women in developing countries. Thus, it is necessary to offer novel therapies to treat this malignancy. Astemizole has been suggested as a novel and interesting anticancer agent because it targets several proteins involved in cancer including Eag1 (ether à-go-go-1) potassium channels. Eag1 has been proposed as a tumor marker for different types of cancer. Actually, we previously suggested Eag1 channels as cervical cancer and dysplasia markers. Besides, Eag1 has been proposed as a therapeutic target for different malignancies. However, the effect of astemizole in cervical cancer cells is unknown. Therefore, we investigated the effect of astemizole on the proliferation and apoptosis of cervical cancer cells.
Five cervical cancer cell lines (HeLa, SiHa, CaSki, INBL, and C-33A) were cultured according to manufacturer's instructions. Eag1 protein expression was studied by immunocytochemistry. Cell proliferation was assayed with the MTT method, and apoptosis was investigated by flow cytometry.
Eag1 protein expression was observed in different cell lines. Astemizole decreased cell proliferation in up to 40% and increased apoptosis severalfold in all the cell lines studied.
Our results suggest astemizole as a potential therapy for cervical cancer.
An ecofriendly Citrus paradisi peel extract mediated
synthesis of TiO2 nanoparticles is reported under sonication. U.V.-
vis, Transmission electron microscopy, Dynamic light scattering, and
X-ray analyses are performed to characterize the formation of TiO2
nanoparticles. It is almost spherical in shape, having a size of 60–140
nm and the XRD peaks at 2θ = 25.363° confirm the characteristic
facets for anatase form. The synthesized nanocatalyst is highly active
in the decomposition of methyl orange (64 mg/L) in sunlight (~73%)
for 2.5h.
A simple, efficient, and ecofriendly method has been developed for the exclusive synthe
sis of iron oxide nanoparticles using an aqueous extract of Passiflora tripartita var. moll
issima fruit.Transmission electron microscopy (TEM) and Dynamic light scattering (DL
S) analysis shows that the average particle size of spherical iron oxide nanoparticles is
22.3 ± 3 nm.The synthesized nanocatalyst is highly active for the synthesis of biologic
ally significant 2-arylbenzimidazoles. The reaction was carried out under mild condition
with excellent yields.The catalyst is easily separated by magnet and recyclable without
significant loss of activity.
The authors describe the synthesis of gold nanoparticles (GNPs) at room temperature using an aqueous extract of Hovenia dulcis fruit and the antioxidant and antibacterial activities of the GNPs obtained. The devised method provides a simple, cost-effective aqueous means of producing spherical and hexagonal GNPs of size ∼20 nm. The synthesized GNPs were characterized by UV–vis spectrum and obtain a peak at 536 nm. Fourier transform infrared (FT-IR) spectroscopy results showed that the extract containing some biomolecules accountable for both reducing as well as capping gold ions into GNPs. Transmission electron microscopic (TEM) studies of the particles revealed a dominance of spherical particles with a very few hexagonal GNPs. The face centered cubic structure of the GNPs was confirmed by X-ray diffraction (XRD) peaks at 38°, 44°, 64° and 77°, which were indexed to the (1 1 1), (2 0 0), (2 2 0), and (3 1 1) planes with clear circular spots in the selected area electron diffraction (SAED). Elemental analysis was performed by energy dispersive X-ray analysis (EDX). In addition, the authors investigated in vitro antioxidant and antibacterial properties of the biosynthesized GNPs, which were found to be significant.
We report a facile approach to synthesizing low generation poly(amidoamine) (PAMAM) dendrimer-stabilized gold nanoparticles (Au DSNPs) for in vivo computed tomography (CT) imaging applications. In this study, amine-terminated generation 2 PAMAM dendrimers were employed as stabilizers to form gold nanoparticles via a simple hydrothermal method. The formed aminated Au DSNPs were then acetylated to neutralize the dendrimer terminal amines, rendering the particles with improved biocompatibility. The final formed acetylated Au DSNPs were characterized via different techniques. We show that the formed Au DSNPs with an Au core size of 5.6 nm are relatively uniform and stable at different pH (5–8) and temperature (4–50 °C) conditions. X-ray attenuation coefficient measurements show that the Au DSNPs display approximately the same X-ray attenuation property as that of Omnipaque, a clinically used iodinated contrast agent. Importantly, the acetylated Au DSNPs showed much better performance in CT imaging of the major organs of rats (heart, liver, kidney, spleen, and bladder) in vivo than Omnipaque, likely due to their nanometer size and thus prolonged blood circulation time. The formed Au DSNPs may be used as a promising contrast agent for CT imaging of different biological systems.
An efficient cold-mechanical/sonic-assisted extraction technique was developed for extraction of genipin from genipap (Genipa americana) peel. Ultrasound assisted extraction (285W, 24kHz) was performed at 5, 10 and 15°C for 5, 10 and 15min. After cold-extraction, genipin was separated from pectin and proteins by aid of fungal pectinesterase. The maximum yield of non-cross-linked genipin was 7.85±0.33mg/g, at 10°C for 15min by means of ultrasound extraction. The protein amount in extracts decreased in all samples. If mechanical process is combined with ultrasound assisted extraction the yield is increased by 8 times after the pectinesterase-assisted polyelectrolyte complex formation between pectic polysaccharides and proteins, avoiding the typical cross-linking of genipin. This novel process is viable to obtain non-cross-linked genipin, to be used as a natural colorant and cross-linker in the food and biotechnological industries.
Gold nanoparticles (NPs) are rapidly and efficiently formed under ambient conditions with a novel and highly-efficient sonochemical promoter. Despite of the presence of free oxygen, 3-glycidoxypropyltrimethoxysilane (GPTMS) showed remarkable efficiency in promoting the reduction rate of Au (III) than that of conventional promoters (primary alcohols). This is likely attributed to the formation of a variety of radical scavengers, which are alcoholic products from sonochemical hydrolysis of the epoxide group and methoxysilane moieties of GPTMS under weakly acidic conditions. Interestingly, the promotion is quenched by amine- or thiol-functionalized alkoxysilane, thereby producing marginal amounts of gold NPs. Furthermore, products of hydrolyzed GPTMS were confirmed to attach on the surface of gold NPs by attenuated total reflectance-Fourier transform infrared spectroscopy. However, according to transmission electron microscopy images, gold NPs that were produced in the presence of GPTMS tend to fuse with each other as condensation of silanols occurs, forming worm- or nugget-like gold nanostructures. The use of long chain surfactants (i.e. polyethylene glycol terminated with hydroxyl or carboxyl) inhibited the fusion, leading to mono-dispersed gold NPs. Additionally, the fact that this approach requires neither an ultrasound source with high frequency nor anaerobic conditions provides a huge advantage. These findings could potentially open an avenue for rapid and large-scale green-synthesis of gold NPs in future work.
An understanding of the interactions between nanoparticles and biological systems is of significant interest. Studies aimed at correlating the properties of nanomaterials such as size, shape, chemical functionality, surface charge, and composition with biomolecular signaling, biological kinetics, transportation, and toxicity in both cell culture and animal experiments are under way. These fundamental studies will provide a foundation for engineering the next generation of nanoscale devices. Here, we provide rationales for these studies, review the current progress in studies of the interactions of nanomaterials with biological systems, and provide a perspective on the long-term implications of these findings.
A method of green chemistry synthesis of gold nanoparticles using lactic acid as a reducing agent is reported. The size and shape of gold nanoparticles are modulated by varying the ratio of metal salt and lactic acid in the reaction medium. The nanoparticles obtained are characterised by UV-vis, transmission electron microscopy (TEM) and X-ray diffraction (XRD). Crystalline nature of the nanoparticles in the face-centred cubic structure is confirmed by the peaks in the XRD pattern corresponding to (1 1 1), (2 0 0), (2 2 0) and (3 1 1) planes, which are bright circular spots in the selected area electron diffraction (SAED) and clear lattice fringes in the high-resolution TEM image. It is found that the size and shape of gold nanoparticles are strongly influenced by the molar ratio of HAuCl<sub>4</sub> to lactic acid. Based on these results, a potential mechanism of this method of gold nanoparticle synthesis is also discussed. In future, more biological and medical applications of gold nanoparticles prepared by this method could be found based on their biocompatibility and solubility in aqueous solutions of lactic acid.
Highly effective separation of colloidal gold nanorods/nanoplates from co-produced isotropic nanoparticles has been achieved by selective precipitation triggered by salt.
This critical review provides an overall survey of the basic concepts and up-to-date literature results concerning the very promising use of gold nanoparticles (AuNPs) for medicinal applications. It includes AuNP synthesis, assembly and conjugation with biological and biocompatible ligands, plasmon-based labeling and imaging, optical and electrochemical sensing, diagnostics, therapy (drug vectorization and DNA/gene delivery) for various diseases, in particular cancer (also Alzheimer, HIV, hepatitis, tuberculosis, arthritis, diabetes) and the essential in vitro and in vivo toxicity. It will interest the medicine, chemistry, spectroscopy, biochemistry, biophysics and nanoscience communities (211 references).
The present investigation was done to explore the potential of Lantana camara (L. camara) flower in the fabrication of gold nanoparticles (AuNPs). The shape and size of AuNPs have been successfully controlled by introducing small amounts of L. camara flower extract. It produced spherical nanogold of average size 10.6 +/- 2.9 nm without any aggregation and showed significant photocatalytic degradation activity of the methylene blue (>62%, 10 mg/L) in the presence of solar light. In addition, the experimental approach is inexpensive, rapid and eco-friendly for industrial scale production of nanoparticles.
Silver nanoparticles have been synthesized and stabilized by using Sacha inchi (SI) oil. The synthesized nanoparticles were characterized by using UV–vis spectroscopy, transmission electron microscopy...
Composite of sol–gel and PVP stabilized gold nanoparticles has been synthesized chemically and is used as an immobilization matrix for tyrosinase enzyme. The composite was spin coated on ITO electrode which was then characterized for its optical and electrochemical behavior. Cyclic voltametric study of ITO/Sol–AuNPs composite electrode showed well defined redox couple for Fe+ ions which is due to high electro-conductivity supplied mainly by gold nanoparticle coverage. The capacitance and faradic current are found to be 6.0 × 10−5 mF and 3.172 × 10−4 A respectively. The analytical performance of composite based catechol biosensor has been evaluated as a function of catechol concentration, buffer concentration and buffer pH. The system showed linearity from 1.0 × 10−6 M to 6 × 10−6 M with sensitivity of 0.01 A/M and LOD as 3 × 10−7 M. Effect of presence of gallic acid, catechin and cresol have been studied using amperometry which showed that these species does not interfere with catechol estimation.
Water is one of the essential enablers of life on earth. Beginning with the origin of the earliest form of life in seawater, it has been central to the evolution of human civilizations. Noble metals have been similarly associated with the prosperity of human civilizations through their prominent use in jewellery and medical applications. The most important reason for the use of noble metals is the minimal reactivity at the bulk scale, which can be explained by a number of concepts such as electrochemical potential, relativisitic contraction, molecular orbital theory, etc. Recently, water quality has been associated with the development index of society. A number of chemical and biological contaminants have endangered the quality of drinking water. An overview of important events during last 200 years in the area of drinking water purification is presented. Realizing the molecular nature of contamination in drinking water, significant progress has been made to utilize the chemistry of nanomaterials for water purification. This article summarizes recent efforts in the area of noble metal nanoparticle synthesis and the origin of their reactivity at the nanoscale. The application of noble metal nanoparticle based chemistry for drinking water purification is summarized for three major types of contaminants: halogenated organics including pesticides, heavy metals and microorganisms. Recent efforts for the removal, as well as ultralow concentration detection of such species, using noble metal nanoparticles are summarized. important challenges during the commercialization of nano-based products are highlighted through a case study of pesticide removal using noble metal nanoparticles. Recent efforts in drinking water purification using other forms of nanomaterials are also summarized. The article concludes with recent investigations on the issue of nanotoxicity and its implications for the future. (C) 2009 Elsevier B.V. All rights reserved.
Extensive degradation experiments and NMR measurements are reported, which lead to expression I for genipin. Its absolute configuration has been established by degradation to the dibasic acid XIIIa, which was shown to be the antipode of one of the nepetic acids derivable from nepetalactone (XI). The close biogenetic relationship of genipin to aucubin, plumieride, and other monoterpenoids is emphasized. Attention is also called to the behavior of some genipin degradation products towards lithium aluminum hydride resulting in cleavage of the dihydropyran ring.
A colorimetric method for quantitative measurement of free amino groups of water soluble chitin derivatives is described.
The method utilizes genipin as a natural and specific reagent for determining the concentration of free amino groups in samples
of water soluble chitin derivatives. The blue color adduct (complex) formed during genipin reaction with free amino groups
was measured at about 589 nm and Beer-Lambert’s law obeyed over the concentration range of 50 to 300 mg/L. Parameters of analytical
conditions were considered and kept constant during the experimental procedure. Highly acetylated water soluble chitin derivatives
can be differentiated from water soluble chitosan using this genipin method. The colorimetric method with genipin was proved
to be a rapid and efficient technique to determine the free amino groups in water soluble chitin derivatives. This method
can also be applied for the detection of the enzymatic activity of chitindeacetylase.
Keywords
Genipa americana
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Gardenia jasmonides
-glucosamine-chitin-chitosan-oligosaccharide
The application of the dynamic light scattering (DLS) method for determining the size distribution of colloidal gold nanoparticles in a range of 1–100 nm is discussed. It is shown that rotational diffusion of nonspherical strongly scattering particles with sizes of larger than 30–40 nm results in the appearance of a false peak in a size range of about 5–10 nm. In this case, the uncritical application of the DLS method may yield particle volume or number size distributions different from those obtained by transmission electron microscopy. For weakly scattering particles with diameters of smaller that 20 nm, the DLS method
demonstrates an additional peak of intensity distribution in the region of large sizes that is related to particle aggregates or byproduct particles rather than individual nanoparticles. Practical methods for solving the problem of false peaks are discussed. It is established that the width of the DLS distribution does not correspond to transmission electron microscopy data and is overestimated. The advantages and drawbacks of the methods are compared and it is noted that, at present, the DLS method is the only instrument suitable for nonperturbative and sensitive diagnostics of relatively slow aggregation processes with characteristic times on the order of 1 min. In particular, this method can be used to diagnose gold nanoparticle conjugate aggregation initiated by biospecific interactions on their surface.
The Direct Analysis in Real Time (DART) ionization source coupled with a quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) system has the capability to desorb analytes directly from samples from complex Chinese herbal preparations without sample cleanup or chromatographic separation.
In this work, a method based on DART/Q-TOF MS/MS has been developed for rapid determination of geniposide present in 'Re Du Ning Injections', a Chinese herbal preparation. The method has been evaluated for both qualitative and quantitative analysis of geniposide in Re Du Ning Injections.
Variables including polarity for ion detection, DART gas heater temperature, matrix effect and sample presentation speed were investigated. The quantitative method was validated with respect to linearity, sensitivity, repeatability, precision and accuracy by using both internal and external standards. A comparison of the results obtained using the DART-based method was made with those obtained using a conventional High-Performance Liquid Chromatography/Diode-Array Detector (HPLC/DAD) by analyzing geniposide in four batches of Re Du Ning Injections.
The DART/Q-TOF MS/MS-based method provides a rapid, efficient and powerful method to analyze compounds from complex Traditional Chinese Medicines with limited sample preparation thus reducing time and complexity of quality control for those materials.
Genipin, a crystalline and well defined chemical compound, is extracted from gardenia fruits according to a modern microbiological process. As a water-soluble bi-functional crosslinking reagent, it reacts promptly with chitosan (and with proteins or amines in general) thus producing blue-coloured fluorescent hydrogels. The reaction mechanism between chitosan and genipin is well understood for a variety of experimental conditions. The resulting crosslinked complexes are not cytotoxic for the animal and human cells so far examined. The safety and the beneficial actions of genipin emerge from a number of research projects in the areas of the therapies of diabetes, periodontitis, cataract, hepatic dysfunction, as well as in wound repair and nerve regeneration. Food sciences, forensic chemistry and cytology have also provided evidence of the safety of its use. The most important applications of genipin in conjunction with chitosan are the preparation of elastic and resistant gels such as the cartilage substitutes, the manufacture of drug carriers for controlled release, the encapsulation of biological products and living cells, and the medication of wounds in animals and humans. Genipin might replace glutaraldehyde with the advantages of stability and biocompatibility of the crosslinked products whose quality assessment and manipulation would be easier.
In this presentation, a reverse micelle technique was described to create colloid gold nanoparticles and their self-organization into superlattices. Gold nanoparticles were prepared by the reduction of HAuCL4 in CTAB/octane+1-butanol/H2O reverse micelle system using NaBH4 as reducing agent. Dodecanethiol (C12H25SH) was used to passivate the gold nanoparticles immediately after formation of the gold colloid. After re-dispersing in toluene under ultrasonication, a supernatant containing nearly monodispersed dodecanethiol-capped gold nanoparticles was obtained. Self-organization of the gold nanoparticles into 1D, 2D and 3D superlattices was observed on the carbon-coated copper grid by TEM. UV–vis absorption spectra were also used to characterize the gold colloids with and without dodecanethiol capping.
A study was conducted to demonstrate the use of gold nanoparticles (AuNP) in chemical and biological sensing. AuNPs possessed distinct physical and chemical attributes that made them excellent scaffolds for the fabrication of novel chemical and biological sensors. AuNPs were synthesized in a straightforward manner and made highly stable, while possessing unique optoelectronic properties and providing high surface-to-volume ratio with excellent biocompatibility using appropriate ligands. These synthetic routes and properties of AuNPs made them excellent probes for different sensing strategies. A variety of other ligands had been used to passivate and functionalize AuNPs, while most AuNP functionalization had been done using thiol or thiolated ligands.
The interest in possible health benefits of flavonoids has increased owing to their potent antioxidant and free radical scavenging activities observed in vitro. Nevertheless, the antioxidant efficacy of flavonoids in vivo is less documented and their prooxidant properties have been actually described in vivo. Due to their prooxidant properties, they are able to cause oxidative damage by reacting with various biomolecules, such as lipids, proteins and DNA. Hence, the aim of this review is to discuss both the antioxidant and prooxidant effects of flavonoids.
The increasing number of bacterial strains that are resistant to available pharmaceutical compounds is a vital issue for public health. Innovative approaches will be required to improve the methods for both diagnosis and destruction of these organisms. Here, we consider the possible role that can be played by technologies based on gold nanoparticles. Gold nanoparticles generally are considered to be biologically inert but can be engineered to possess chemical or photothermal functionality. A growing body of research is devoted to the potential use of these nanoparticles in the diagnosis and treatment of bacterial infections. The results are both promising and intriguing, and suggest a range of new strategies to identify, target or destroy pathogenic organisms.
The Genipa americana plant contains geniposide [3] and geniposidic acid [2] in the fruits and geniposidic acid [2] in the leaves. On callus induction, the plant produces tarennoside [1], geniposidic acid [2], and gardenoside [4] in high levels. The leaves of Ge. americana plants redifferentiated from the callus tissues produce 2.
Four new iridoid glucosides, called genamesides A-D, have been isolated from the fruit of Genipa americana L. (Rubiaceae), along with four known iridoid glucosides, geniposidic acid, geniposide, gardenoside and genipin-gentiobioside. Their chemical structures were determined on the basis of spectroscopic data.
Three new monoterpenoids, called genipacetal, genipamide, and genipaol, were isolated from the fruit of Genipa americana L. (Rubiaceae), along with the four known iridoids genipin, gardendiol, deacetyl asperulosidic acid methyl ester, and shanzhiside. Their chemical structures were determined on the basis of spectroscopic data.
Because of its potent antioxidant function and important role in clinical treatment, alpha-tocopherol (vitamin E) is a good starting point in the development of new synthetic antioxidants with improved properties. In this paper the first example of antioxidant-functionalized gold nanoparticles, Au@Trolox, was synthesized by self-assembly of thiol ligands derived from Trolox, a vitamin E analogue, on gold nanoparticles. DPPH* (2,2-diphenyl-1-picrylhydrazyl) radical scavenging experiments revealed that the rate constant for the reaction of Au@Trolox with DPPH* was about eight times greater than that for Trolox. The product analysis showed that both the quinonoid and the diepoxide forms were possible oxidized products of the chromanol group of Au@Trolox treated with DPPH* radical. No remarkable influence was found on the antioxidant activity of Au@Trolox when the coverage rate of the antioxidant group on the surface of the gold was varied. All our results proved that the assembly of chromanol groups on gold nanoparticles could efficiently enhance the activity of the vitamin E-derived antioxidant, which presents a potential new strategy for antioxidant design with novel perspectives in potential applications.
Gold nanoparticles (AuNPs) provide non-toxic carriers for drug and gene delivery applications. With these systems, the gold core imparts stability to the assembly, while the monolayer allows tuning of surface properties such as charge and hydrophobicity. An additional attractive feature of AuNPs is their interaction with thiols, providing an effective and selective means of controlled intracellular release.
Cytotoxic activity of G. americana fruit extract (a and b) and as-synthesized GNPs (c and d) against human cancer cell lines A-549 and HeLa
- Fig
Fig. 8. Cytotoxic activity of G. americana fruit extract (a and b) and as-synthesized GNPs (c and d) against human cancer cell lines A-549 and HeLa.
- P Ghosh
- G Han
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P. Ghosh, G. Han, M. De, C.K. Kim, V.M. Rotello, Gold nanoparticles in delivery applications, Adv. Drug Deliv. Rev. 60 (2008) 1307-1315.
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M. Ono, N. Ishimatsu, C. Masuoka, H. Yoshimitsu, R. Tsuchihashi, M. Okawa, J. Kinjo,
T. Ikeda, T. Nohara, Three new monoterpenoids from the fruit of Genipa americana,
Chem. Pharm. Bull. 55 (2007) 632-634.
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