Nervous system exposure of different classes of nanoparticles: A review on potential toxicity and mechanistic studies

Nanoparticles (NPs) are generally defined as very small particles in the size range of 1-100 nm. Due to the rapid development of modern society, many new materials have been developed. The widespread use of NPs in medical applications, the food industry and the textile industry has led to an increase in NPs in the environment and the possibility of human contact, which poses a serious threat to human health. The nervous system plays a leading role in maintaining the integrity and unity of the body and maintaining a harmonious balance with the external environment. Therefore, based on two categories of organic and inorganic NPs, this paper systematically summarizes the toxic effects and mechanisms of NPs released into the nervous system. The results showed that exposure to NPs may damage the nervous system, decrease learning and cognitive ability, and affect embryonic development. Finally, a remediation scheme for NPs entering the body via the environment is also introduced. This scheme aims to reduce the neurotoxicity caused by NPs by supplementing NPs with a combination of antioxidant and anti-inflammatory compounds. The results provide a valuable reference for future research in this field.

Biofabricated nanomaterials in sustainable agriculture: insights, challenges and prospects

One ever-evolving and ever-demanding critical human endeavour is the provision of food security for the growing world population. This can be done by adopting sustainable agriculture through horizontal (expanding the arable land area) and vertical (intensifying agriculture through sound technological approaches) interventions. Customized formulated nanomaterials have numerous advantages. With their specialized physico-chemical properties, some nanoparticulated materials improve the plant's natural development and stress tolerance and some others are good nanocarriers. Nanocarriers in agriculture often coat chemicals to form composites having utilities with crop productivity enhancement abilities, environmental management (such as ecotoxicity reduction ability) and biomedicines (such as the ability to control and target the release of useful nanoscale drugs). Ag, Fe, Zn, TiO2, ZnO, SiO2and MgO nanoparticles (NPs), often employed in advanced agriculture, are covered here. Some NPs used for various extended purposes in modern farming practices, including disease diagnostics and seed treatment are also covered. Thus, nanotechnology has revolutionized agrotechnology, which holds promise to transform agricultural (ecosystems as a whole to ensure food security in the future. Considering the available literature, this article further probes the emergent regulatory issues governing the synthesis and use of nanomaterials in the agriculture sector. If applied responsibly, nanomaterials could help improve soil health. This article provides an overview of the nanomaterials used in the distribution of biomolecules, to aid in devising a safer and eco-friendly sustainable agriculture strategy. Through this, agri-systems that depend on advanced farming practices might function more effectively and enhance agri-productivity to meet the food demand of the rising world population.

Metal-based nanoparticle in cancer treatment: lessons learned and challenges

Cancer, being one of the deadliest diseases, poses significant challenges despite the existence of traditional treatment approaches. This has led to a growing demand for innovative pharmaceutical agents that specifically target cancer cells for effective treatment. In recent years, the use of metal nanoparticles (NPs) as a promising alternative to conventional therapies has gained prominence in cancer research. Metal NPs exhibit unique properties that hold tremendous potential for various applications in cancer treatment. Studies have demonstrated that certain metals possess inherent or acquired anticancer capabilities through their surfaces. These properties make metal NPs an attractive focus for therapeutic development. In this review, we will investigate the applicability of several distinct classes of metal NPs for tumor targeting in cancer treatment. These classes may include gold, silver, iron oxide, and other metals with unique properties that can be exploited for therapeutic purposes. Additionally, we will provide a comprehensive summary of the risk factors associated with the therapeutic application of metal NPs. Understanding and addressing these factors will be crucial for successful clinical translation and to mitigate any potential challenges or failures in the translation of metal NP-based therapies. By exploring the therapeutic potential of metal NPs and identifying the associated risk factors, this review aims to contribute to the advancement of cancer treatment strategies. The anticipated outcome of this review is to provide valuable insights and pave the way for the advancement of effective and targeted therapies utilizing metal NPs specifically for cancer patients.

Use of nanotechnology-based nanomaterial as a substitute for antibiotics in monogastric animals

Nanotechnology has emerged as a promising solution for tackling antibiotic resistance in monogastric animals, providing innovative methods to enhance animal health and well-being. This review explores the novel use of nanotechnology-based nanomaterials as substitutes for antibiotics in monogastric animals. With growing global concerns about antibiotic resistance and the need for sustainable practices in animal husbandry, nanotechnology offers a compelling avenue to address these challenges. The objectives of this review are to find out the potential of nanomaterials in improving animal health while reducing reliance on conventional antibiotics. We examine various forms of nanomaterials and their roles in promoting gut health and also emphasize fresh perspectives brought by integrating nanotechnology into animal healthcare. Additionally, we delve into the mechanisms underlying the antibacterial properties of nanomaterials and their effectiveness in combating microbial resistance. By shedding light on the transformative role of nanotechnology in animal production systems. This review contributes to our understanding of how nanotechnology can provide safer and more sustainable alternatives to antibiotics.

Tamarindus indica seed polysaccharide-copper nanocomposite: An innovative solution for green environment and antimicrobial studies

The purpose of this study was to synthesize ecofriendly nano-composite in which agricultural waste (seeds of Tamarindus indica) was used to synthesize tamarind seed polysaccharides (TSP) and its composite with copper nanoparticles (Cu-NPs) for the purpose of green and clean environment as well as reduction of green-house gases. Confirmation of extracted TSP, synthesized nanocomposite was carried out using FTIR, SEM, PXRD and EDX techniques. In FTIR analysis TSP gives a strong broad peak at 3331 cm-1 due to -OH group and in case of composite its intensity is reduced which might be due to the interactions between -OH and Cu+2 ions. SEM analysis gives that TSP have irregular and rough surface while Cu-NPs exhibited spherical morphology and composite showed clustering of spherical shape to rough surface. EDX analysis quantitatively represented copper having atomic ratio 0.57 % which confirms the synthesis of composite. Furthermore, synthesized composite demonstrated excellent antibacterial activity against gram-positive (S.aureus) and gram-negative bacteria (E.coli) even greater than standard medicine (ciprofloxacin). From this study it was revealed that agriculture waste can be utilized to make environment green as well as synthesized composite from agricultural waste seed also displayed excellent antimicrobial activities which directs that they can be utilized in medical field. This study aims to assess the antimicrobial properties of the nanocomposite, aiming to contribute to the development of effective antimicrobial agents. Through these objectives, the research seeks to bridge the gap between green technology and antimicrobial efficacy, offering a promising avenue for both environmental conservation and healthcare advancements.

Fabrication of CuNPs Using Schiff Base Ligand and Their Catalytic Reduction of Pharmaceutical Drugs, Fluorescence Selective Detection of Cd2+, Antimicrobial, and Antioxidant Activities

Here, we have approached the synthesis of copper nanoparticles (CuNPs) Schiff base (5-trifluoromethoxy-2-(((2chloro-5-(methyl)phenyl)imino)methyl)phenol)). The synthesized CuNPs were characterized by UV-vis spectroscopy, PL, FTIR, powder XRD, and TEM analysis. From the UV-vis absorption spectroscopy, an absorption peak was observed at 585 nm. As a result of the powder XRD and TEM studies, spherical particle sizes ranged between 4 and 10 nm. FT-IR analysis confirmed the presence of functional groups ‒OH, C=C, -C=N-, and C‒H triggers the synthesis of CuNPs. Further, the catalytic property of the CuNPs were revealed by the degradation of pharmaceutical drugs such as Capecitabine (CAP) and Ciprofloxacin (CIP) in 90 min of reaction time in the presence of NaBH4. The reaction kinetics followed pseudo-first-order with k-values (rate constant) 0.248 min-1 and 0.307 min-1. In addition, the synthesized CuNPs have exhibited selective sensing detection of Cd2+ metal ions in different range of concentration (10-100 µM) by spectrofluorometrically with the limit of detection (LOD) is 0.0284 nM and limit of quantification (LOQ) is 0.0586 nM. The CuNPs revealed significant antioxidant activities against DPPH as a common free radical at 50 µg/mL with 71.24% of scavenging activity. The maximum antimicrobial potential and zone of inhibition of P. Aeruginosa is 17.25±0.8 mm and A. niger is 12.1 mm by using CuNPs.

Promising biomedical systems based on copper nanoparticles: Synthesis, characterization, and applications

Copper and copper oxide nanoparticles (CuNPs) have unique physicochemical properties that make them highly promising for biomedical applications. This review discusses the application of CuNPs in biomedicine, including diagnosis, therapy, and theranostics. Recent synthesis methods, with an emphasis on green approaches, are described, and the latest techniques for nanoparticle characterization are critically analyzed. CuNPs, including Cu2O, CuO, and Cu, have significant potential as anti-cancer agents, drug delivery systems, and photodynamic therapy enhancers, among other applications. While challenges such as ensuring biocompatibility and stability must be addressed, the state-of-the-art research reviewed here provides strong evidence for the efficacy and versatility of CuNPs. These multifunctional properties have been extensively researched and documented, showcasing the immense potential of CuNPs in biomedicine. Overall, the evidence suggests that CuNPs are a promising avenue for future research and development in biomedicine. We strongly support further progress in the development of synthesis and application strategies to enhance the effectiveness and safety of CuNPs for clinical purposes.

Comparative effects of supplementary different copper forms on performance, protein efficiency, digestibility of nutrients, immune function and architecture of liver and kidney in growing rabbits

The various sources of supplemented copper had a different impact on the animal performance based on their bioavailability. The current study compared the effects of supplementary copper oxide (CuO), copper acetate (Cu-acetate) and copper nanoparticles (Cu-NP) on performance, immune function, nutrients digestibility and architecture of the liver and kidney of growing rabbits for eight weeks. Sixty rabbits (581 ± 6.56 g) were randomly allocated to four treatments as follows: basal diet, 100 mg copper/kg diet as CuO, 100 mg copper/kg diet as Cu-acetate and 50 mg copper/kg diet as Cu-NP. Cu-acetate and Cu-NP improved specific growth rate, final weight and daily weight gain. Cu-NP supplementation had higher feed intake, feed conversion, protein efficiency, hematocrit and hemoglobin values compared with other copper forms. All copper sources showed higher levels of serum complement component 3, Immunoglobulin M, lysozyme activity and the digestibility of nitrogen-free extract, dry matter and organic matter. As a result, increased nutritive values were detected when the rabbits were fed copper-supplemented diets. No liver and kidney architecture alterations were identified between the experimental groups. In conclusion, both dietary Cu-NP and Cu-acetate were more efficient than CuO in enhancing growth and seem promising in fattening rabbit nutrition.

Efficacy of copper nanoparticles encapsulated in soya lecithin liposomes in treating breast cancer cells (MCF-7) in vitro

Cancer is one of the leading causes of death, which has attracted the attention of the scientific world to the search for efficient methods for treatment. With the great development and regeneration of nanotechnology over the last 25 years, various nanoparticles in different structures, shapes and composites provide good potential for cancer therapy. There are several drugs approved by FDA used in breast cancer treatment like Cyclophosphamide, Doxorubicin Hydrochloride, Femara, Herceptin, etc. Each has several side effects as well as treatment, which limits the use of drugs due to heart failure, pulmonary dysfunction, or immunodeficiency. Recently, such side effects are greatly reduced by using innovative delivery techniques. Some drugs have been approved for use in cancer treatment under the concept of drug delivery, such as Doxil (liposomal loaded doxorubicin). The purpose of this study is to investigate the effect of copper nanoparticles (CuNPs) as a drug model for cancer treatment, either in their free form or encapsulated in Soy lecithin liposomes (SLP) from plant origin as a cheap source of lipids. CuNPs were prepared by the chemical reduction method and loaded onto SLP through the thin film hydration method. The drug model Cu/SLP was successfully combined. The characteristics of the free CuNPs, liposomes, and the combined form, zeta potential, size distribution, drug encapsulation efficiency (EE%), drug release profile, Fourier transform infrared (FTIR), and transmission electron microscopy (TEM), were checked, followed by an in vitro study on the breast cancer cell line Mcf-7 as a model for cytotoxicity evaluation. The optimal Cu/SLP had a particle mean size of 81.59 ± 14.93 nm, a negative zeta potential of - 50.7 ± 4.34 mV, loaded CuNPs showed an EE% of 78.9%, a drug release profile for about 50% of the drug was released after 6 h, and FTIR analysis was recorded. The cytotoxicity assay showed that the IC50 of Cu/SLP is smaller than that of free CuNPs. These results give clear evidence of the efficacy of using the combined Cu/SLP rather than CuNPs alone as a model drug carrier prepared from plant origin against cancer, both medically and economically.

Emilia sonchifolia leaf extract-mediated green synthesis, characterization, in vitro biological activities, photocatalytic degradation and in vivo Danio rerio embryo toxicity of copper nanoparticles

The green-mediated synthesis of copper nanoparticles is of great interest in nanotechnology and is regarded as a low-cost and environmentally beneficial method. Herein, Emilia sonchifolia leaf extract was employed as a reducing and capping agent for the green production of copper nanoparticles. In this work, we focused on the in vivo and in vitro biological studies of copper nanoparticles, which were evaluated in zebrafish (Danio rerio) embryos. The biological effects from the in vitro studies of the copper nanoparticles included cytotoxicity (in human cells) and anti-diabetic, anti-inflammatory, and antibacterial activity. Furthermore, the effectiveness of the greenly produced copper nanoparticles for photocatalysis was also evaluated, and then SEM-EDX, FTIR, XRD, TGA and UV-vis spectroscopy were used to characterise the copper nanoparticles. The results of the toxicity test on zebrafish embryos demonstrated that the green-produced copper nanoparticles had a significantly low harmful effect. According to the results, the copper nanoparticles showed dose-dependent cytotoxicity against human keratinocytes (HaCaT) and human breast cancer cells (MCF-7), which was higher than that of the Emilia sonchifolia leaf extract. The green copper nanoparticles also demonstrated more potent anti-inflammatory, antibacterial and anti-diabetic properties. In the photocatalytic experiment, the produced copper nanoparticles successfully degraded the organic methylene blue dye. Thus, it can be concluded that copper nanoparticles can be employed for drug administration in both in vitro and in vivo settings in biomedical applications. Additionally, as catalysts, these copper nanoparticles can be employed for the removal of organic dyes.

Effects of differently incubated cupric oxide nanoparticles on the granulosa cells of caprine ovary in vitro

In the nanoscience metal and metal oxide, nanoparticles have a prominent place because of their vast applications. Recent finding shows that in addition to size, there are other critical factors governing the biological response of nanoparticles. These factors include surface chemistry and shape that influences solubility, rate of diffusion, drug delivery, melting temperature, and colour of the nanoparticles. It is thus the present study that was aimed to investigate the effect of temperature on the shape and size of nanoparticles and related cytotoxicity of these particles on ovarian granulosa cells. Cupric oxide nanoparticles (CuONPs) were synthesized using a simple, efficient, and reproducible precipitation method involving the reduction of Cu metal salt with sodium hydroxide and then incubation of the precipitates at 70 °C for 5 h. Subsequently, this prepared sample was divided into 3 subsamples and incubated at 3 different temperatures, i.e. 70 °C, 150 °C, and 350 °C for 5 h to study the effect of temperature on the particles. The products were characterized by XRD, FTIR, HRTEM, and FESEM. Characterization of the particles revealed that all particles were monoclinic crystalline in nature and had a size range from 9 to 60 nm. Particles were of different shapes: spherical, needle, and capsule. The toxicity of each particle was determined on granulosa cells by exposing cells for 24 h at 2 different doses. Toxicological results showed the size and shape-related toxicity of nanoparticles where spherical shapes were significantly more toxic than capsule-shaped particles.

Design and characterization of an urea-bridged PMO supporting Cu(II) nanoparticles as highly efficient heterogeneous catalyst for synthesis of tetrazole derivatives

In this work, a new periodic mesoporous organosilica with urea-bridges produced by the reaction of (3-aminopropyl)triethoxysilane and toluene-2,4-diisocyanate (APS-TDU-PMO) is introduced. The obtained APS-TDU-PMO was found to be an appropriate support for loading of Cu(II) nanoparticles to afford supramolecular Cu@APS-TDU-PMO nanocomposite. Uniformity and mesoporosity of both synthesized nanomaterials including APS-TDU-PMO and Cu@APS-TDU-PMO were proved by different spectroscopic, microscopic or analytical techniques including FTIR, EDX, XRD, FESEM, TEM, BET, TGA and DTA. Furthermore, the prepared Cu@APS-TDU-PMO nanomaterial was also used, as a heterogeneous and recyclable catalyst, for the synthesis of tetrazole derivatives through cascade condensation, concerted cycloaddition and tautomerization reactions. Indeed, the main advantages of this Cu@APS-TDU-PMO is its simple preparation and high catalytic activity as well as proper surface area which enable it to work under solvent-free conditions. Also, the introduced Cu@APS-TDU-PMO heterogeneous catalyst showed good stability and reusability for six consecutive runs to address more green chemistry principles.

Autophagy and apoptosis mediated nano-copper-induced testicular damage

Nano-copper has been increasingly employed in various products. In previous studies, we showed that nano-copper caused damage in the rat testis, but it remains unclear whether the toxic reaction can affect the reproductive function. In this study, following 28 d of exposure to nano-copper at a dose of 44, 88, and 175 mg/kg/day, there was a decrease in sperm quality, fructose content, and the secretion of sex hormones. Nano-copper also increased the level of oxidative stress, sperm malformation rate, and induced abnormal structural changes in testicular tissue. Moreover, Nano-copper upregulated the expression of apoptosis-related protein Bax and autophagy-related protein Beclin, and downregulated the expression of Bcl2 and p62. Furthermore, nano-copper (175 mg/kg) downregulated the protein expression of AMPK, p-AKT, mTOR, p-mTOR, p-4E-BP1, p70S6K, and p-p70S6K, and upregulated the protein expression of p-AMPK. Therefore, nano-copper induced damage in testicular tissues and spermatogenesis is highly related to cell apoptosis and autophagy by regulating the Akt/mTOR signaling pathway. In summary, excess exposure to nano-copper may induce testicular apoptosis and autophagy through AKT/mTOR signaling pathways, and damage the reproductive system in adult males, which is associated with oxidative stress in the testes.

Glycerol Valorization over ZrO2-Supported Copper Nanoparticles Catalysts Prepared by Chemical Reduction Method

Copper nanoparticles (NPs) and ZrO2-supported copper NPs (Cu NPs/ZrO2) were synthesized via a chemical reduction method applying different pH (4, 7 and 9) and evaluated in a glycerol dehydration reaction. Copper NPs were characterized with transmission electron microscopy (TEM) and UV–vis spectroscopy. Transmission electron microcopy (TEM) results revealed a homogeneous distribution of copper NPs. A hypsochromic shift was identified with UV–vis spectroscopy as the pH of the synthesis increased from pH = 4 to pH = 9. Zirconia-supported copper NPs catalysts were characterized using N2 physisorption, X-ray diffraction (XRD), TEM, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), temperature-programmed desorption of ammonia (NH3-TPD) and N2O chemisorption. The presence of ZrO2 in the chemical reduction method confirmed the dispersion of the copper nanoparticles. X-ray diffraction indicated only the presence of tetragonal zirconia patterns in the catalysts. XPS identified the Cu/Zr surface atomic ratio of the catalysts. TPR patterns showed two main peaks for the Cu NPS/ZrO2 pH = 9 catalyst; the first peak between 125 and 180 °C (region I) was ascribed to more dispersed copper species, and the second one between 180 and 250 °C (region II) was assigned to bulk CuO. The catalysts prepared at pH = 4 and pH = 7 only revealed reduction at lower temperatures (region I). Copper dispersion was determined by N2O chemisorption. With NH3-TPD it was found that Cu NPs/ZrO2 pH = 9 exhibited the highest total quantity of acidic sites and the highest apparent kinetic constant, with a value of 0.004 min−1. The different pH applied to the synthesis media of the copper nanoparticles determined the resultant copper dispersion on the ZrO2 support, providing active domains for glycerol conversion.

Performance of Swarnadhara breeder hens supplemented with reduced levels of different copper forms

Background and Aim:

Copper (Cu) is a vital mineral involved in various physiological and biochemical processes, growth, and productivity of animals and birds. Birds can absorb only a small fraction of Cu and most is excreted, contaminating soil and aquatic environment which is toxic for microorganisms, plants, animals, and humans. This study evaluated the possibility of use of organic and nanoparticles sources of Cu to reduce supplementation level without compromising the performance of breeder hens.

Materials and Methods:

A total of 224 Swarnadhara breeder hens were divided into seven treatment groups having four replicates in each. The basal diet (control) containing 20 ppm inorganic Cu (100% of standard recommendation) and six test diets containing 20, 15, and 10 ppm (100, 75, and 50% of standard recommendation) from Cu organic source, and 15, 10, and 5 ppm (75, 50, and 25%) from Cu nanoparticles (Cu-NP), were prepared and offered to respective treatment groups for a duration of 20 weeks.

Results:

The hen day egg production, hen housed egg production, feed conversion ratio egg mass, albumen index, yolk index, total fat content, and color score were not affected by the source and inclusion level of Cu. The feed intake was significantly (p<0.05) lower at 15 ppm and egg weight was significantly (p<0.05) higher at 10 ppm Cu-NP supplemental level, but was non-significant in other treatment groups compared to control. The body weight gain was significantly (p<0.05) higher at 20 ppm organic and 15 ppm Cu-NP inclusion. The egg shape index and Haugh unit were significantly (p<0.05) lower at 10 and 15 ppm of Cu-NP inclusion level, respectively. The shell thickness was improved (p<0.05) at 20 and 15 ppm organic and 15 and 10 ppm Cu-NP inclusion level. The egg fertility rate was shown to be significantly (p<0.05) higher at 20 ppm organic Cu inclusion group, but the hatchability based on total number of eggs set improved (p<0.05) at 20 and 15 ppm organic Cu inclusion level while all treatment groups were comparable to control. The hatchability of fertilized egg and chick’s quality significantly (p<0.05) improved, while embryonic and chick mortality after hatching before-sorting was significantly (p<0.05) reduced at 15 ppm of Cu-NP inclusion group.

Conclusion:

It was concluded that the inorganic Cu can be replaced with 50% of organic or 25% of nanoparticles form of Cu without jeopardizing the breeder hens’ productivity, egg quality characteristics, hatchability, and progeny.

Plant-mediated synthesis of nanoparticles and their antimicrobial activity against phytopathogens

Nanotechnology is an emerging science with a wide array of applications involving the synthesis and manipulation of materials with dimensions in the range of 1-100 nm. Nanotechnological applications include diverse fields such as pharmaceuticals, medicine, the environment, food processing and agriculture. Regarding the latter, applications are mainly focused on plant growth and crop protection against plagues and diseases. In recent years, the biogenic reduction of elements such as Ag, Au, Cu, Cd, Al, Se, Zn, Ce, Ti and Fe with plant extracts has become one of the most accepted techniques for obtaining nanoparticles (NPs), as it is considered an ecological and cost-effective process without the use of chemical contaminants. The objective of this work was to review NPs synthesized by green chemistry using vegetable extracts, as well as their use as antimicrobial agents against phytopathogenic fungi and bacteria. Given the need for alternatives to control and integrate management of phytopathogens, this review is relevant to agriculture, although this technology is barely exploited in this field. © 2020 Society of Chemical Industry.

New Hybrid Copper Nanoparticles/Conjugated Polyelectrolyte Composite with Antibacterial Activity

In the search for new materials to fight against antibiotic-resistant bacteria, a hybrid composite from metallic copper nanoparticles (CuNPs) and a novel cationic π-conjugated polyelectrolyte (CPE) were designed, synthesized, and characterized. The CuNPs were prepared by chemical reduction in the presence of CPE, which acts as a stabilizing agent. Spectroscopic analysis and electron microscopy showed the distinctive band of the metallic CuNP surface plasmon and their random distribution on the CPE laminar surface, respectively. Theoretical calculations on CuNP/CPE deposits suggest that the interaction between both materials occurs through polyelectrolyte side chains, with a small contribution of its backbone electron density. The CuNP/CPE composite showed antibacterial activity against Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative (Escherichia coli and Salmonella enteritidis) bacteria, mainly attributed to the CuNPs’ effect and, to a lesser extent, to the cationic CPE.

Controllable fabrication and self-assembly of Cu nanostructures: the role of Cu2+ complexes

The controllable fabrication of low dimensional nanostructures and the assembly of nanostructures into hierarchical higher order structures at the atomic or molecular level have been two hot-spots of current nano research. In this work, the fabrication and self-assembly of Cu nanostructures were carried out by reducing Cu²⁺ complexes in a mixed aqueous solution of NaOH and hydrazine hydrate at a water bath temperature of 60 °C. The reduction products were characterized using a metalloscope, a scanning electron microscope, a transmission electron microscope and a powder X-ray diffractometer. It was found that the fabrication and self-assembly of Cu nanostructures can be easily realized by controlling the types of Cu²⁺ complexes such as [Cu(OH)₄]²⁻, [Cu(EDA)₂]²⁺ and [Cu(EDA)(OH)₂]. The authors further analyzed the important roles of Cu²⁺ complexes in the fabrication and self-assembly of Cu nanostructures. It was concluded that the Cu²⁺ complexes in the aqueous solution would spontaneously arrange into a certain soft template according to the principle of “like dissolves like” and the action of electrostatic forces of positive and negative charges. The as-formed templates determine the fabrication and self-assembly routes and the final products of the Cu nanostructures. Therefore, it provides a controllable and universal method for both fabrication and self-assembly of Cu nanostructures, which may have potential applications in the fields of electronic and optoelectronic nanodevices in the future.

Cu²⁺ complexes in aqueous solution would spontaneously arrange into a certain soft template, which determines the fabrication and self-assembly routes and the final products of Cu nanostructures.

A method to detect immunoreactions on the basis of current vs. concentration slope - an electrochemical approach

The emergence of novel infectious diseases is rising with time and is a major threat to the society. The recent outbreak of infectious coronavirus disease has made a huge impact in our lives. The massive outbreak of the disease revealed that there is room for development of new diagnostics tools and methods to screen huge numbers of samples in the shortest possible time. Our current work relates to an electronic diagnostic system and method that rapidly detects the presence of an antigen in solution. Our designed system is capable of separating the immunocomplex formation on the basis of the slope it produces in contrast to the controls, when oxidation peak current is plotted against the concentration of the reactant after electrochemistry measurement. In this system, antibody conjugated copper nanoparticles synthesized by the electroexplosion method has played the key role. The values of the slopes of copper nanoparticles (CuNPs) was found to be −3.7637, whereas those for CuNP conjugated Antibody and CuNPAntibodyAntigen were −2.3044 and −0.8332, respectively. Hence, the current method could become one of the easiest and fastest method for the electronic detection of an immune reaction and a good replacement for the time-consuming, label-based assays in multistep reaction.

Synthesis of Cu nanoparticle by Electro-Explosion of Wire (EEW) technique for immunosensing application.

Oral exposure of pregnant rats to copper nanoparticles caused nutritional imbalance and liver dysfunction in fetus

Copper nanoparticles (Cu NPs) are increasingly used as an animal feed additive in China. In previous studies, it was determined that Cu NPs can penetrate the placental barrier, however, its toxic effects on the fetus have not yet been elucidated. Therefore, in this study, we investigated the potential fetal toxic effects of Cu NPs. Cu NPs were orally administered to pregnant Sprague-Dawley rats from gestation days (GDs) 3-18 at a dose of 60, 120, and 180 mg/kg/day. Cesarean sections were conducted on GD 19. During fetal examination, no toxicities were observed regarding general clinical signs, however, Cu NPs significantly decreased fetal body weight, body length, and liver weights. Cu ions and Cu MPs exhibited similar effects on the fetal development. Cu NPs increased the liver concentration of Cu, and decreased protein levels and Fe in fetuses. Cu NPs also increased oxidative stress and inflammation in the fetus after pregnant rats were exposed to high doses of Cu NPs. Oral exposure to Cu NPs during pregnancy increased Cu concentrations in the fetus, which not only affected fetal development, but also significantly induced oxidative stress and inflammatory responses in fetal liver. Taken together, these findings are valuable to evaluate fetal risk assessment after oral exposure of Cu NPs during pregnancy. Additional comprehensive toxicity studies are deemed necessary to clarify the underlying mechanisms involved.

Effect of Zinc Oxide Nano-Additives and Soybean Biodiesel at Varying Loads and Compression Ratios on VCR Diesel Engine Characteristics

The present investigation is directed towards synthesis of zinc oxide (ZnO) nanoparticles and steady blending with soybean biodiesel (SBME25) to improve the fuel properties of SBME25 and enhance the overall characteristics of a variable compression ratio diesel engine. The soybean biodiesel (SBME) was prepared using the transesterification reaction. Numerous characterization tests were carried out to ascertain the shape and size of zinc oxide nanoparticles. The synthesized asymmetric ZnO nanoparticles were dispersed in SBME25 at three dosage levels (25, 50, and 75 ppm) with sodium dodecyl benzene sulphonate (SDBS) surfactant using the ultrasonication process. The quantified physicochemical properties of all the fuels blends were in symmetry with the American society for testing and materials (ASTM) standards. Nanofuel blends demonstrated enhanced fuel properties compared with SBME25. The engine was operated at two different compression ratios (18.5 and 21.5) and a comparison was made, and best fuel blend and compression ratio (CR) were selected. Fuel blend SBME25ZnO50 and compression ratio (CR) of 21.5 illustrated an overall enhancement in engine characteristics. For SBME25ZnO50 and CR 21.5 fuel blend, brake thermal efficiency (BTE) increased by 23.2%, brake specific fuel consumption (BSFC) were reduced by 26.66%, and hydrocarbon (HC), CO, smoke, and CO2 emissions were reduced by 32.234%, 28.21% 22.55% and 21.66%, respectively; in addition, the heat release rate (HRR) and mean gas temperature (MGT) improved, and ignition delay (ID) was reduced. In contrast, the NOx emissions increased for all the nanofuel blends due to greater supply of oxygen and increase in the temperature of the combustion chamber. At a CR of 18.5, a similar trend was observed, while the values of engine characteristics were lower compared with CR of 21.5. The properties of nanofuel blend SBME25ZnO50 were in symmetry and comparable to the diesel fuel.

Review of Copper and Copper Nanoparticle Toxicity in Fish

This review summarizes the present knowledge on the toxicity of copper and copper nanoparticles (CuNPs) to various fish species. In previous decades, the excessive usage of metal and metallic nanoparticles has increased significantly, increasing the probability of the accumulation and discharge of metals in various trophic levels of the environment. Due to these concerns, it is important to understand the toxicity mechanisms of metals and metallic nanoparticles before they lead to unhealthy effects on human health. In this review paper, we specifically focus on the effect of metal copper and CuNPs on different fish organs under different physiochemical parameters of various water bodies. Nowadays, different forms of copper have distinctive and specific usages, e.g., copper sulfate is a well-established pesticide which is used to control the growth of algae in lakes and ponds. Deactivating the fungi enzymes prevents fungal spores from germinating. This process of deactivation is achieved via the free cupric ions, which are established as the most toxic forms of copper. Complexes of copper with other ligands may or may not be bioavailable for use in aquatic organisms. On the other hand, CuNPs have shown cost-effectiveness and numerous promising uses, but the toxicity and availability of copper in a nanoparticle form is largely unknown, Additionally, physiochemical factors such as the hardness of the water, alkalinity, presence of inorganic and organic ligands, levels of pH, and temperature in various different water bodies affect the toxicity caused by copper and CuNPs. However, comprehensive knowledge and data regarding the pattern of toxicity for copper metal ions and CuNPs in marine organisms is still limited. In this review, we carry out a critical analysis of the availability of the toxicological profiles of copper metal ions and CuNPs for different fishes in order to understand the toxicity mechanisms of copper and CuNPs. We believe that this review will provide valuable information on the toxicological profile of copper, which will further help in devising safe guidelines for the usage of copper and CuNPs in a sustainable manner.

Biodistribution and toxicity assessment of copper nanoparticles in the rat brain

AIMS

The increase in the usage of copper nanoparticles (Cu NPs) in the industrial and medical fields has raised concerns about their possible adverse effects. The present study aims to investigate the potential adverse effects of Cu NPs on the brain of adult male Wistar rats through the estimation of some oxidative stress parameters and acetylcholinesterase (AChE) activity.

BASIC PROCEDURES

Cu NPs were prepared and characterized using different techniques: Dynamic Light Scattering, X-Ray Diffraction, Transmission and Scanning Electron Microscopy, Fourier transform Infrared Spectroscopy, in addition to Energy Dispersive X-ray Spectroscopy. Rats were divided into two groups: Cu NPs-treated group (IV injected with 15 mg/kg ˷ 13 nm Cu NPs for 2 successive days) and a control group (injected with saline). Rats of the 2 groups were decapitated simultaneously after 48 h of the last injection. The Cu content in different brain areas was analyzed using inductively coupled plasma mass spectrometry. Moreover, the effect of Cu NPs on brain edema was evaluated. The behavior of rats in an open-field was also examined 24 h post the last injection.

MAIN FINDINGS

Significant increases of Cu content in the cortex, cerebellum, striatum, thalamus and hippocampus were found. Moreover, Cu NPs lead to the induction of oxidative stress condition in the thalamus, hypothamaus and medulla. In addition, Cu NPs induced significant increases in AChE activity in the medulla, hippocampus, striatum besides midbrain. Cu NPs-injected rats showed also decreased exploratory behaviour.

PRINCIPAL CONCLUSION

The results obtained in the present study point to the importance of toxicity assessments in evaluating the efficiency of Cu NPs for the safe implementation in different applications.

Green synthesis of copper nanoparticles using leaf extract of Ageratum houstonianum Mill. and study of their photocatalytic and antibacterial activities

The novel copper nanoparticles (CuNPs) were synthesized using aqueous leaf extract of Ageratum houstonianum Mill. (AHLE). The green synthesized AH-CuNPs have a useful dye degradation property in the existence of daylight. The photocatalytic activity of AH-CuNPs was evaluated against an azo dye congo red (CR), whereas, same NPs displayed no effect on other dyes. The CR was completely degraded within 2 h, and the reaction rate was followed by pseudo-first-order kinetics, and the rate constant was recorded 3.1 × 10−4 s−1, (R2 = 0.9359). Antibacterial activity of green synthesized AH-CuNPs was studied against gram-negative bacterium Escherichia coli (MTCC no. 40), and a significant growth inhibition was recorded with 12.43 ± 0.233 mm zone of inhibition. The AH-CuNPs were characterized through UV-visible spectroscopy, XRD, SEM, FT-IR, TEM, and zeta particle size analyzer. Ageratum houstonianum mediated green synthesized copper nanoparticles (AH-CuNPs) were cubic, hexagonal, and rectangular in shape, with average size of ∼80 nm. The optical band gap was 4.5 eV, which was investigated using UV-visible spectroscopy, and the band gap value revealed that AH-CuNPs were semiconductor materials.

Computational design and clinical demonstration of a copper nanocluster based universal immunosensor for sensitive diagnostics

Nanoparticle based sensors are good alternatives for non-enzymatic sensing applications due to their high stability, superior photoluminescence, biocompatibility and ease of fabrication, with the only disadvantage being the cost of the synthesis process (owing to the expensive precursors and infrastructure). For the first time, we report the design of an immunosensor employing streptavidin conjugated copper nanocluster, developed at a much lower cost compared to other nanomaterials like noble metal nanoparticles and quantum dots. Using in silico tools, we have tried to establish the dynamics of conjugation of nanocluster to the streptavidin protein, based on EDC-NHS coupling. The computational simulations have successfully explained the crucial role played by the components of the immunosensor leading to an efficient design capable of high sensitivity. In order to demonstrate the functioning of the Copper Nanocluster ImmunoSensor (CuNIS), HIV-1 p24 biomarker test was chosen as the model assay. The immunosensor was able to achieve an analytical limit of detection of 23.8 pg mL^-1 for HIV-1 p24 with a linear dynamic range of 27-1000 pg mL^-1. When tested with clinical plasma samples, CuNIS based p24 assay showed 100% specificity towards HIV-1 p24. With the capability of multiplexed detection and a cost of fabrication 100 times lower than that of the conventional metal nanoclusters, CuNIS has the potential to be an essential low-cost diagnostic tool in resource-limited settings.

Reduction of the Cytotoxicity of Copper (II) Oxide Nanoparticles by Coating with a Surface-Binding Peptide

Copper (II) oxide nanoparticles (CuO-NPs) have been studied as potential antimicrobial agents, similar to silver or platinum nanoparticles. However, the use of excess NPs is limited by their safety and toxicity in beneficial microflora and human cells. In this study, we evaluated the cytotoxicity of CuO-NPs by coating with a novel cyclic peptide, CuO binding peptide 1 (CuBP1), cyclic-SCATPFSPQVCS, which binds to the surface of CuO-NPs. CuBP1 was identified using biopanning of a T7 phage display system and was found to promote the aggregation of CuO-NPs under mild conditions. The treated CuO-NPs with CuBP1 caused the reduction of the cytotoxicity against Escherichia coli, Lactobacillus helveticus, and five other microorganisms, including bacteria and eukaryotes. Similar effects were also demonstrated against human embryonic kidney (HEK293) cells in vitro. Our findings suggested that the CuO-NPs coated with a surface-binding peptide may have applications as a safe antimicrobial agent without excessive cytotoxic activity against beneficial microflora and human cells. Moreover, a similar tendency may be achieved with other metal particles, such as silver or platinum NPs, by using optimal metal binding peptides.

Fabrication of Polylactide/Carbon Nanopowder Filament using Melt Extrusion and Filament Characterization for 3D Printing

In this study, less expensive mesoporous nano carbon (NC) infused in polylactide (PLA) thermoplastic filaments were fabricated to improve the electrical properties and maintaining sufficient strength for 3D printing. Solution blending was used for PLA-NC nanocomposite fabrication and melt extrusion was employed to make cylindrical filaments. Mechanical and electrical properties of 1–20[Formula: see text]wt.% of NC-filaments were investigated and significant improvement of conductivity (3.76[Formula: see text]S/m) and sufficient yield strength (35[Formula: see text]MPa) were obtained. SEM images exhibited uniform dispersion of NC in polymer matrix and DSC results showed no significant changes in the glass transition temperature ([Formula: see text]) for all the compositions. Perspective uses of this filament are for fabrication of electrical wires in 3D printed robots, drones, prosthetics, orthotics and others.

Synthesis of Copper Nanoparticles in Ethylene Glycol by Chemical Reduction with Vanadium (+2) Salts

Copper nanoparticles have been synthesized in ethylene glycol (EG) using copper sulphate as a precursor and vanadium sulfate as an atypical reductant being active at room temperature. We have described a technique for a relatively simple preparation of such a reagent, which has been electrolytically produced without using standard procedures requiring an inert atmosphere and a mercury cathode. Several stabilizing agents have been tested and cationic capping agents have been discarded owing to the formation of complex compounds with copper ions leading to insoluble phases contaminating the metallic nanoparticles. The elemental copper nanoparticles, stabilized with polyvinylpyrrolidone (PVP) and sodium dodecyl sulphate (SDS), have been characterized for composition by energy dispersive X-ray spectroscopy (EDS), and for size by dynamic light scattering (DLS), and transmission electron microscopy (TEM), giving a size distribution in the range of 40-50 nm for both stabilizing agents. From a methodological point of view, the process described here may represent an alternative to other wet-chemical techniques for metal nanoparticle synthesis in non-aqueous media based on conventional organic or inorganic reductants.

Using Response Surface Methodology in Synthesis of Ultrafine Copper Nanoparticles by Electrolysis

Electrolysis is a method used for producing copper (Cu) nanoparticles at faster rate and at low cost in ambient conditions. The property of Cu nanoparticles prepared by electrolysis depends on their process parameters. The influence of selected process parameters such as copper sulfate (CuSo4) concentration, electrode gap and electrode potential difference on particle size was investigated. To optimize these parameters response surface methodology (RSM) was used. Cu nanoparticles prepared by electrolysis were characterized by using X-ray diffraction (XRD) and scanning electron microscope (SEM). After reviewing the results of analysis of variance (ANOVA), mathematical equation was created and optimized parameters for producing Cu nanoparticles were determined. The results confirm that the average size of Cu particle at the optimum condition was found to be 17[Formula: see text]nm and they are hexagonal in shape.