Biosynthesis and effects of copper nanoparticles on plants

Copper nanoparticles have improved properties compared to the bulk copper material. Copper nanoparticles indeed find applications in gas sensors, heat transfer fluids, catalysis, solar energy and batteries. Antibacterial and antifungal activities of copper nanoparticles find applications in the agriculture and healthcare sectors. Nonetheless, careless use of copper nanoparticles may cause environmental pollution and health effects. Here we review the biosynthesis of copper nanoparticles using plant materials, named phytosynthesis, and micro-organisms. We also discuss the effect of copper nanoparticles on crops and pathogenic micro-organisms. Copper nanoparticles varying in sizes from 5 to 295 nm have been synthesized using leaf extracts and latex from plants, and using bacteria and fungi. Biosynthesized copper nanoparticles show good antimicrobial activity inhibiting the growth of pathogenic bacteria and pathogenic fungi. Copper nanoparticles enhance the germination and growth of some plants at lower concentrations, whereas high concentrations result in retarded growth.     

Manufactured silver and gold nanoparticles-induced apoptosis by caspase-pathway in human cell lines

Abstract

Metallic nanoparticles have emerged as an important class of nanomaterials for a wide range of industrial and medical applications. Because of the intensive commercial applications, risk assessment of these nanoparticles is of great importance. In the present study, the human hepatoma and leukemia cells were used to characterize the apoptotic effects of silver nanoparticles (4.7 and 42?nm) and gold nanoparticles (30?nm). Apoptotic cells were identified by chromatin condensation and flow cytometry analysis, using Annexin V/PI, TUNEL and caspase activation assays. Flow cytometry analysis showed that the three metallic nanoparticles induced apoptotic cell death in a concentration and time dependent-manner. Moreover, the three nanoparticles induced activation of caspase-3 and -7 in hepatoma and leukemia cells. Apoptotic effects were stronger after exposure of both cell lines with 4.7?nm silver nanoparticles than those obtained with 42?nm silver and 30?nm gold nanoparticles. In conclusion, silver (4.7 and 42?nm) and gold (30?nm) nanoparticles induced apoptosis in hepatoma and leukemia cells via the caspase dependent pathway. The smaller silver nanoparticles (4.7?nm) had a greater ability to induce apoptosis in both cell lines.     

Large-scale green synthesis of Cu nanoparticles

This article reports a novel, eco-friendly herbal method to synthesize Cu nanoparticles in large scales. Cu nanoparticles are an alternative to Ag and Au nanoparticles and have potential applications in many industrial areas. Many synthetic routes have been documented for the preparation of copper nanoparticles, but very few routes are eco-friendly and large-scale. We report here the preparation of Cu nanoparticles from aqueous CuSO₄ using non-toxic and inexpensive materials like curd, milk, and herbal extracts such as tamarind and lemon juice as capping agents. X-ray diffraction and transmission electron microscopy show that produced particles are nanocrystalline copper 20–50 nm in size with a face-centered cubic structure. Fourier-transformed infrared spectroscopy evidences the role of organic acids in the capping process. The novelty of this work is the synthesis of Cu nanoparticles from CuSO₄ without electricity and using non-toxic, cheap capping agents.     

Facile synthesis of Pd nanoparticles on SiO2 for hydrogenation of biomass-derived furfural

This report shows that furfuryl alcohol can be selectively produced from the hydrogenation of furfural using supported Pd nanoparticles. Furfuryl alcohol is widely used as solvent and chemical intermediate for the synthesis of fine chemicals. Here, various Pd nanoparticles supported on mesoporous SiO₂ (Pd/SiO₂) were simply fabricated by a wet impregnation using palladium nitrate. Physical properties of Pd/SiO₂ nanoparticles were studied by X-ray diffraction, energy-dispersive, X-ray analysis, N₂ adsorption and desorption isotherms and transmission electron microscopy. Results show a high dispersion of Pd nanoparticles with small size. Pd nanoparticles catalyzed very efficiently the hydrogenation of furfural to furfuryl alcohol with 76 % selectivity under mild conditions. Overall, the catalyst developed could find applications for the production of chemicals from biomass.     

Size-dependent in vitro cytotoxicity assay of gold nanoparticles

Gold nanoparticles (AuNps) may serve as a promising model to address the size-dependent biological response of cell lines. Their size can be controlled with great precision during chemical synthesis. AuNps have potential applications in drug delivery, cancer diagnosis, and therapy, in the food industry, and for environmental remediation. However, some of the recent literature contains conflicting data regarding the cytotoxicity of gold nanoparticles. Against this background, a systematic study of water soluble gold nanoparticles stabilized by citrate ranging in size from 3?nm to 45?nm were synthesized. The cytotoxicity of these particles were tested by employing the (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide reduction assay), the neutral red cellular uptake assay, and lactate dehydrogenase release assay. Noticeable differences in the cytotoxic effects depending on the assay, and the nanoparticle size have been found. Citrate stabilized gold nanoparticles with sizes of 3?nm, 8?nm, and 30?nm were more sensitive to the cell lines and caused gradual cell death within 24?h at higher concentrations. This results in IC50 values ranging from 57 to 78?μgmL^?1 depending on the particle size, and cell line combinations. In contrast, AuNps with diameters of 5?nm, 6?nm, 10?nm, 17?nm, and 45?nm were nontoxic up to three to four fold higher concentrations, and at long-term exposure.     

Biofabrication of calcium phosphate nanoparticles using the plant Mimusops elengi

Nanoparticles are now widely applied in products. The synthesis of nanomaterials using biological materials is an emerging field, notably for medical applications because biologically derived compounds can be safe. For instance, calcium phosphate is a natural biomineral that possesses an excellent biocompatibility due to its chemical similarity to human hard tissue such as bone and teeth. Here, we synthesized calcium phosphate nanoparticles by using bark extract of Spanish cherry (Mimusops elengi). Calcium phosphate nanoparticles showed an absorbance at 275 nm by UV–visible analysis and particle size of 25 nm by nanoparticle tracking and analysis. Fourier transform infrared spectroscopy revealed the presence of aromatic amines as a capping and reducing agent. Transmission electron microscopy showed the presence of polydispersed spherical nanoparticles with an average size of 50 nm. Measurements of zeta potential revealed the stability of the synthesized calcium phosphate nanoparticles. These particles demonstrated antibacterial activity against Streptococcus mutans, Staphylococcus aureus and Escherichia coli. We conclude that the synthesis of calcium phosphate nanoparticles by using a M. elengi is easy, eco-friendly and scalable.     

Remediation of soil and groundwater contaminated with organic chemicals using stabilized nanoparticles: Lessons from the past two decades

▪ Overviewed evolution and environmental applications of stabilized nanoparticles. ▪ Reviewed theories on particle stabilization for enhanced reactivity/deliverability. ▪ Examined various in situ remediation technologies based on stabilized nanoparticles. ▪ Summarized knowledge on transport of stabilized nanoparticles in porous media. ▪ Identified key knowledge gaps and future research needs on stabilized nanoparticles. Due to improved soil deliverability and high reactivity, stabilized nanoparticles have been studied for nearly two decades for in situ remediation of soil and groundwater contaminated with organic pollutants. While large amounts of bench- and field-scale experimental data have demonstrated the potential of the innovative technology, extensive research results have also unveiled various merits and constraints associated different soil characteristics, types of nanoparticles and particle stabilization techniques. Overall, this work aims to critically overview the fundamental principles on particle stabilization, and the evolution and some recent developments of stabilized nanoparticles for degradation of organic contaminants in soil and groundwater. The specific objectives are to: 1) overview fundamental mechanisms in nanoparticle stabilization; 2) summarize key applications of stabilized nanoparticles for in situ remediation of soil and groundwater contaminated by legacy and emerging organic chemicals; 3) update the latest knowledge on the transport and fate of stabilized nanoparticles; 4) examine the merits and constraints of stabilized nanoparticles in environmental remediation applications; and 5) identify the knowledge gaps and future research needs pertaining to stabilized nanoparticles for remediation of contaminated soil and groundwater. Per instructions of this invited special issue, this review is focused on contributions from our group (one of the pioneers in the subject field), which, however, is supplemented by important relevant works by others. The knowledge gained is expected to further advance the science and technology in the environmental applications of stabilized nanoparticles.     

ZnO nanoparticles dissolution,penetration and toxicity in human epidermal cells. Influence of pH

Environmental Chemistry Letters - Zinc oxide (ZnO) nanoparticles are widely used in cosmetics, food packaging, drug delivery and biosensors. There is therefore a risk of toxicity for organisms,...     

纳米银对鱼类的毒性效应研究进展

纳米银作为一种新兴的纳米材料,由于其独特的抗菌性能而被广泛应用于各种商业化产品中。广泛的应用增加了它进入环境尤其是水环境的机率,从而对鱼类等水生生物产生潜在毒性效应。因此,近年来陆续开展了关于纳米银对鱼类的毒理学研究。本文根据国内外文献查阅及分析,综述了纳米银的制备、特性、应用、释放情况以及近几年来纳米银对鱼类的毒理学研究进展,对今后进一步开展相关研究工作提供参考。     

斑马鱼在纳米金属及金属氧化物毒性研究中的应用

纳米金属及金属氧化物材料在催化、涂料、电子、机械和生物医学领域大量生产和应用,因此,对纳米金属材料及其氧化物可能给环境以及人体健康带来的潜在影响和风险需要有足够的认识.本文就近年来纳米金属及金属氧化物对斑马鱼毒性的研究进展进行综述,为人们进一步认识和更好地应用纳米材料奠定基础.     

A multi-integrated approach on toxicity effects of engineered TiO2 nanoparticles

The new properties of engineered nanoparticles drive the need for new knowledge on the safety, fate, behavior and biologic effects of these particles on organisms and ecosystems. Titanium dioxide nanoparticles have been used extensively for a wide range of applications, e.g, self-cleaning surface coatings, solar cells, water treatment agents, topical sunscreens. Within this scenario increased environmental exposure can be expected but data on the ecotoxicological evaluation of nanoparticles are still scarce. The main purpose of this work was the evaluation of effects of TiO₂ nanoparticles in several organisms, covering different trophic levels, using a battery of aquatic assays. Using fish as a vertebrate model organism tissue histological and ultrastructural observations and the stress enzyme activity were also studied. TiO₂ nanoparticles (Aeroxide® P25), two phase composition of anatase (65%) and rutile (35%) with an average particle size value of 27.6±11 nm were used. Results on the EC₅₀ for the tested aquatic organisms showed toxicity for the bacteria, the algae and the crustacean, being the algae the most sensitive tested organism. The aquatic plant Lemna minor showed no effect on growth. The fish Carassius auratus showed no effect on a 21 day survival test, though at a biochemical level the cytosolic Glutathione-S-Transferase total activity, in intestines, showed a general significant decrease (p<0.05) after 14 days of exposure for all tested concentrations. The presence of TiO₂ nanoparticles aggregates were observed in the intestine lumen but their internalization by intestine cells could not be confirmed.     

Auswirkungen nanotechnologischer Entwicklungen auf die Umwelt

Background

Nanotechnology is about discovering, developing and using materials consisting in their primary stage at a size within the low nanometer range. These ultrafine particles offer new properties and opportunities. Even if the synthesis of nanoparticles has been discovered not until during the last decades, the exposure of humans to ultrafine particles occurred long before, due to the generation of ultrafine particles in ambient air during combustion processing.

Aim

Within this review, only engineered nanoparticles are considered, because these technical products are associated with many hopes for new applications, while only little information is available about their potential adverse effects. At workpiaces, during manufacturing, in technical applications or in drugs, nanoparticles will always have ‘side effects’ which have carefully to be weighed against their advantages, before they can be released in the environment. Therefore, information about their safety and potential hazards is urgently needed.

Results and Discussion

Along with the technical development of nanoparticles, a public discussion has started, leading to extensive investigations on possible negative ‘side effects’ on human health. Research activities have been strengthened in departments for environmental toxicology, hygiene institutes and other academic facilities to identify hazard and risks during handling and use of these new materials. On the other hand, nanotechnology offers the promise to prematurely identify environmental problems through improved detection and monitoring capabilities, and significantly reduced environmental effects from cleaner manufacturing and synthesis approaches, which results in a reduction or elimination of wastes as well as reduced energy use, and unique remediation solutions as well as pollution strategies.

Conclusions

However, the potential impact of manufactured nanomaterials used in various applications also needs to be evaluated in the context of human health with regard to potential toxicology and routes of exposure, environmental effects, including fate, transport, transformation, bio-availability, and bio-accumulation, and an analysis of product-life cycle.     

(Super)paramagnetic nanoparticles as platform materials for environmental applications: From synthesis to demonstration

• The fabrication of monodisperse, (super)paramagnetic nanoparticles is summarized. • Monolayer and bilayer surface coating structures are described. • Mono/bilayer coated nanoparticles showed high sorption capacities for U, As, and Cr. Over the past few decades, engineered, (super)paramagnetic nanoparticles have drawn extensive research attention for a broad range of applications based on their tunable size and shape, surface chemistries, and magnetic properties. This review summaries our recent work on the synthesis, surface modification, and environmental application of (super)paramagnetic nanoparticles. By utilizing high-temperature thermo-decomposition methods, first, we have broadly demonstrated the synthesis of highly monodispersed, (super)paramagnetic nanoparticles, via the pyrolysis of metal carboxylate salts in an organic phase. Highly uniform magnetic nanoparticles with various size, composition, and shape can be precisely tuned by controlled reaction parameters, such as the initial precursors, heating rate, final reaction temperature, reaction time, and the additives. These materials can be further rendered water stable via functionalization with surface mono/bi-layer coating structure using a series of tunable ionic/non-ionic surfactants. Finally, we have demonstrated platform potential of these materials for heavy metal ions sensing, sorption, and separation from the aqueous phase.     

Green synthesis of metal nanoparticles using Garcinia extracts: a review

Environmental Chemistry Letters - The demand for nanoparticles has been increasing rapidly in recent years due to their unique properties of interest for a wide range of applications. Several...     

Effect of Zinc Oxide nanoparticles on cellular oxidative stress and antioxidant defense mechanisms in mouse liver

Zinc oxide nanoparticles (ZnO₂), a common ingredient of cosmetics has a huge variety of applications. Previous studies reported oxidative stress mediated toxicity of ZnO₂ nanoparticles on various mammalian cell lines. Although zinc (Zn) is an essential mineral at higher concentrations this metal is toxic. The present study focused on size determination by monitoring changes in activities of antioxidant defense mechanism in response to oxidative stress induced by ZnO₂ nanoparticles using mouse liver tissue homogenates. The study also investigated effects of oxidative stress induced DNA damage by determining formation of 8-OHdG in mouse liver homogenate. A cytotoxicity assay was also carried out in L929 cells to determine cell viability. The results of the study indicated that 50μg/ml of ZnO₂ nanoparticles induced 50% cell death. Alterations in antioxidant parameters and 8-OHdG were also noted. Data showed that there was a concentration-dependent fall in cell viability, decrease antioxidant enzyme levels and increase formation of DNA adduct (8-OHdG) when mouse liver tissue homogenate were exposed to ZnO₂ nanoparticles.     

Chitosan nanoparticles preparation and applications

Shell fish processing industry is very common in coastal areas. While processing, only the meat is taken, the head and shells are discarded as waste. On an average, the sea food industry produces 80,000 tons of waste per year. The sheer amount of waste makes degradation a slow process causing accumulation of waste over a period of time. A very simple and effective solution to this environmental hazard is the recycling of shell waste to commercially viable products like chitin. Chitosan is the N-acetyl derivative of chitin obtained by N-deacetylation. Chitosan is widely used in food and bioengineering industries for encapsulation of active food ingredients, enzyme immobilization, as a carrier for controlled drug delivery, in agriculture as a plant growth promoter. Chitosan is also a defense elicitor and an antimicrobial agent. Chitosan has interesting properties such as biodegradability, biocompatibility, bioactivity, nontoxicity and polycationic nature. This review presents structural characteristics and physicochemical properties of chitosan. The methods of preparation of chitosan nanoparticles are detailed. Applications of chitosan nanoparticles are discussed. Applications include drug delivery, encapsulation, antimicrobial agent, plant growth-promoting agent and plant protector.     

Food additives for the synthesis of metal nanoparticles: a review

Environmental Chemistry Letters - Metal nanoparticles have found applications in many fields such as molecular diagnostics, electronic devices and environmental remediation. Nonetheless,...     

Nanosystems for drug delivery of coenzyme Q10

Coenzyme Q10 is an antioxidant present in the human body. Coenzyme Q10 has an essential role in various biochemical reactions. The deficiency of coenzyme Q10 in the body leads to disorders including neurological degeneration, ageing and cancer. Clinical trials have tested coenzyme Q10 as a drug or a dietary supplement. However, the major pharmaceutical issue of coenzyme Q10 delivery is its high molecular weight and poor water solubility. This limitation leads to its poor oral bioavailability. Several methods have been designed to overcome the poor water solubility of coenzyme Q10, such as size reduction and ionization. This article presents nanotechnology-based drug delivery systems for coenzyme Q10 with special emphasis on pharmacokinetic perspectives and clinical relevance. Systems include nanoparticles, solid dispersions, liposomes, nanoemulsions, self-emulsifying drug delivery systems, nanostructured lipid carriers, cyclodextrins and nanocapsules.     

Nanotechnology in cosmetics: a boon or bane?

Recent advances in the field of nanotechnology enabled the manufacturing of elaborated nanometer-sized particles for various biomedical applications. The cosmetic industry is one of the most enthusiastic early adopters of nanotechnology which routinely uses nano-scale ingredients. However, in the absence of mandatory product labeling, it is difficult to estimate the number of cosmetics, sunscreens and personal care products containing nanoparticles that are now commercially available. The increased capacity of nanoparticles to penetrate skin and gain access to human cells is a double-edged sword as it may be useful for medical purposes, but might also result in far greater uptake of substances that exert adverse health effects. Since nanomaterials represent a large group of structurally, physically, and chemically variable substances, specific toxicological studies are required for each product prior to commercialization. This review aims to delineate the most investigated applications, risk and safety considerations, and regulation of nanotechnology in the field of cosmetics.     

Cadmium sulfide nanoparticle induces oxidative stress and pro-inflammatory effects in human lung adenocarcinoma epithelial cells

Cadmium sulfide nanoparticles (CdSNP) are increasingly used in biological applications. This study was undertaken to understand the mechanisms underlying adverse effects of CdSNP using human lung adenocarcinoma epithelial (A549) cells. Cellular toxicity was evaluated by using 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide and neutral red assays. Results showed that CdSNP reduced mitochondrial function and induced lysosomal activity in concentration and time-dependent manner. CdSNP produced oxidative stress as evidenced by reduction of glutathione (GSH) levels and increase in reactive oxygen species and lipid peroxidation levels. Induction of caspase-3 enzymes and condensed, fragmented nuclei was observed in CdSNP-treated cells. Furthermore, the levels of interleukin-8, tumor growth factor and DNA fragmentation were significantly higher in CdSNP exposed cells. Data indicated that toxicity of CdSNP noted in A549 cells may be mediated through oxidative stress. This study warrants more comprehensive assessment of CdSNP prior to industrial applications.