The applications of nanotechnology in food industry

α-Amylase@Ferria: Magnetic Nanocomposites with Enhanced Thermal Stability for Starch Hydrolysis

The present study is devoted to the development of a new class recyclable magnetic catalytic nanocomposites for starch hydrolysis. α-Amylase was entrapped within a magnetite-derived xerogel matrix in a course of a room-temperature sol-gel transition, leading to enzyme immobilization within the pores of a rigid magnetic matrix. For hybrid organo-inorganic composites with enzyme mass fractions less than 10 wt %, no enzyme leaching was observed. At 80 °C, the amylase@ferria composite demonstrates catalytic activity on the level of 10 units/mg and the starch hydrolysis rate comparable to free enzyme, while at 90 °C, the activity of amylase@ferria is at least twice higher than that of free amylase as a result of higher thermal stability of the composite. Entrapped amylase showed excellent stability and lost only 9% of its activity after 21 days of storage in a buffer solution, while free enzyme was totally inactivated after 17 days. The material can be used as either a magnetically separable reusable catalyst or a catalytic ceramic coating with at least 10 cycles of use.

Effects and Mechanism of Nano-Copper Exposure on Hepatic Cytochrome P450 Enzymes in Rats

Although nano-copper is currently used extensively, the adverse effects on liver cytochrome P450 (CYP450) enzymes after oral exposure are not clear. In this study, we determined the effects and mechanisms of action of nano- and micro-copper on the expression and activity of CYP450 enzymes in rat liver. Rats were orally exposed to micro-copper (400 mg/kg), Cu ion (100 mg/kg), or nano-copper (100, 200 and 400 mg/kg) daily for seven consecutive days. Histopathological, inflammatory and oxidative stress were measured in the livers of all rats. The mRNA levels and activity of CYP450 enzymes, as well as the mRNA levels of select nuclear receptors, were determined. Exposure to nano-copper (400 mg/kg) induced significant oxidative stress and inflammation relative to the controls, indicated by increased levels of interleukin (IL)-2, IL-6, interferon (IFN)-γ, macrophage inflammatory protein (MIP-1), total antioxidant capacity (T-AOC), malondialdehyde (MDA), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) after exposure. The levels of mRNA expression of pregnane X receptor (PXR), constitutive androstane receptor (CAR) and aryl hydrocarbon receptor (AHR) were significantly decreased in 400 mg/kg nano-copper treated rats. Nano-copper activated the expression of the NF-kappa B (NF-κB), mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription (STAT)3 signaling pathways. Nano-copper decreased the mRNA expression and activity of CYP 1A2, 2C11, 2D6, 2E1 and 3A4 in a dose-dependent manner. The adverse effects of micro-copper are less severe than those of nano-copper on the CYP450 enzymes of rats after oral exposure. Ingestion of large amounts of nano-copper in animals severely affects the drug metabolism of the liver by inhibiting the expression of various CYP450 enzymes, which increases the risk of drug-drug interactions in animals.

Copper nanoparticles induce early fibrotic changes in the liver via TGF-β/Smad signaling and cause immunosuppressive effects in rats

Copper nanoparticles (Cu NPs) have various uses, including as additives in polymers/plastics, lubricants for metallic coating, and biomedical applications. We investigated the role of transforming growth factor (TGF)-β1 signaling in hepatic damage caused by Cu NPs and explored the effects of a 28-day repeated oral administration to Cu NPs on the immune response. The exposure to Cu NPs caused a dose-dependent increase in Cu levels in the liver and spleen. Cu NPs caused hepatic damage and markedly increased oxidative stress in liver tissues. Cu NPs induced activation of TGF-β1/Smad signaling by induction of vascular endothelial growth factor and matrix metalloproteinase-9. Exposure to Cu NPs also induced activation of Smad-independent pathways, phosphorylation of mitogen-activated protein kinases (MAPKs) and Akt/FoxO3. Consistent with the activation of TGF-β1/Smad-dependent and -independent pathways, Cu NPs markedly increased the deposition and induction of extracellular matrix components, α-smooth muscle actin, and collagens in liver tissues. In addition, repeated exposure to Cu NPs suppressed the proliferation of mitogenically stimulated T- or B-lymphocytes and decreased CD3⁺ (particularly, CD3⁺CD4⁺CD8^-) and CD45⁺ population, followed by decreased levels of immunoglobulins and Th1/Th2 type cytokines. Collectively, Cu NPs caused hepatic damage and induced pro-fibrotic changes, which were closely related to the activation of oxidative stress-mediated TGF-β1/Smad-dependent and -independent pathways (MAPKs and Akt/FoxO3). We confirmed the immunosuppressive effect of Cu NPs via the inhibition of mitogen-stimulated spleen-derived lymphocyte proliferation and suppression of B- or T-lymphocyte-mediated immune responses.

The Role of Mucin in the Toxicological Impact of Polystyrene Nanoparticles

The development of novel oral drug delivery systems is an expanding area of research and both new approaches for improving their efficacy and the investigation of their potential toxicological effect are crucial and should be performed in parallel. Polystyrene nanoparticles (NPs) have been used for the production of diagnostic and therapeutic nanosystems, are widely used in food packaging, and have also served as models for investigating NPs interactions with biological systems. The mucous gel layer that covers the epithelium of the gastrointestinal system is a complex barrier-exchange system that it is mainly constituted by mucin and it constitutes the first physical barrier encountered after ingestion. In this study, we aimed to investigate the effect of polystyrene NPs on mucin and its potential role during NP–cell interactions. For this purpose, we evaluated the interaction of polystyrene NPs with mucin in dispersion by dynamic light scattering and with a deposited layer of mucin using a quartz crystal microbalance with dissipation technology. Next, we measured cell viability and the apoptotic state of three enterocyte-like cell lines that differ in their ability to produce mucin, after their exposure to the NPs. Positive charged NPs showed the ability to strongly interact and aggregate mucin in our model. Positive NPs affected cell viability and induced apoptosis in all cell lines independently of their ability of produce mucin.

Comparative cytotoxicity and apoptotic pathways induced by nanosilver in human liver HepG2 and L02 cells

Silver nanoparticles are used in many commercial products in daily life. Exposure to nanosilver has hepatotoxic effects in animals. This study investigated the cytotoxicity associated with polyvinylpyrrolidone-coated nanosilver (23.44 ± 4.92 nm in diameter) exposure in the human hepatoma cell line (HepG2) and normal hepatic cell line (L02), and the molecular mechanisms induced by nanosilver in HepG2 cells. Nanosilver, in doses of 20-160 μg mL^-1 for 24 and 48 h, reduced cell viability in a dose- and time-dependent manner and induced cell membrane leakage and mitochondria injury in both cell lines; these effects were more pronounced in HepG2 cells than in L02 cells. Intracellular oxidative stress was documented by reactive oxygen species (ROS) being generated in HepG2 cells but not in L02 cells, an effect possibly due to differential uptake of nanosilver by cancer cells and normal cells. In HepG2 cells, apoptosis was documented by finding that ROS triggered a decrease in mitochondrial membrane potential, an increase in cytochrome c release, activation of caspase 3 and caspase 9, and a decrease in the ratio of Bcl-2/Bax. Furthermore, nanosilver activated the Fas death receptor pathway by downregulation of nuclear factor-κB and activation of caspase 8 and caspase 3. These results suggest that apoptosis induced by nanosilver in HepG2 cells is mediated via a mitochondria-dependent pathway and the Fas death receptor pathway. These findings provide toxicological and mechanistic information that can help in assessing the effects of nanosilver in biological systems, including the potential for anticancer activities.

Effect of Functionalised and Non-Functionalised Carbon Nanotubes-Urea Fertilizer on the Growth of Paddy

The roles of multi-walled carbon nanotubes (MWNTs) and functionalised multiwalled carbon nanotubes (fMWNTs) in enhancing the efficacy of urea fertilizer (UF) as plant nutrition for local MR219 paddy variety was investigated. The MWNTs and fMWNTs were grafted onto UF to produce UF-MWNTs fertilizer with three different conditions, coded as FMU1 (0.6 wt. % fMWNTs), FMU2 (0.1 wt. % fMWNTs) and MU (0.6 wt. % MWNTs. The batches of MR219 paddy were systematically grown in accordance to the general practice performed by the Malaysian Agricultural Research and Development Institute (MARDI). The procedure was conducted using a pot under exposure to natural light at three different fertilization times; after a certain number of days of sowing (DAS) at 14, 35 and 55 days. Interestingly, it was found that the crop growth of plants treated with FMU1 and FMU2 significantly increased by 22.6% and 38.5% compared to plants with MU addition. Also, paddy treated with FMU1 produced 21.4% higher number of panicles and 35% more grain yield than MU while paddy treated with FMU2 gave 28.6% more number of panicles and 36% higher grain yield than MU, which implies the advantage of fMWNTs over MWNTs to be combined with UF as plant nutrition. The chemical composition and morphology of UF-MWNTs fertilizers which is further characterised by FTiR and FESEM confirmed the successful and homogeneous grafting of UF onto the fMWNTs.

Nano-selenium and its nanomedicine applications: a critical review

Traditional supplements of selenium generally have a low degree of absorption and increased toxicity. Therefore, it is imperative to develop innovative systems as transporters of selenium compounds, which would raise the bioavailability of this element and allow its controlled release in the organism. Nanoscale selenium has attracted a great interest as a food additive especially in individuals with selenium deficiency, but also as a therapeutic agent without significant side effects in medicine. This review is focused on the incorporation of nanotechnological applications, in particular exploring the possibilities of a more effective way of administration, especially in selenium-deficient organisms. In addition, this review summarizes the survey of knowledge on selenium nanoparticles, their biological effects in the organism, advantages, absorption mechanisms, and nanotechnological applications for peroral administration.

Genotoxicity, biochemical, and biodistribution studies of magnesium oxide nano and microparticles in albino wistar rats after 28-day repeated oral exposure

Increased utilization and exposure levels of Magnesium oxide (MgO) nanoparticles (NPs) to humans and environment may raise unexpected consequences. The goal of this study was to evaluate the toxicological implications of MgO NPs and MPs after 28 day repeated oral administration in Wistar rats with three different doses (250, 500, and 1000 mg/kg). The MgO particles were characterised systematically in order to get more insights of the toxicological behaviour. MgO NPs induced significant DNA damage and aberrations in chromosomes. Moreover, hepatic enzymes released into the systemic circulation caused significant elevated levels of physiological enzymes in blood. NPs could interfere with proteins and enzymes and alter the redox balance in cell environment. Significant accumulation of Mg in all tissues and clearance via urine and faeces was noted in size dependent kinetics. Oral administration of MgO NPs altered the biochemical and genotoxic parameters in dose dependent and gender independent manner.

Impact of nanosilver on gut microbiota: a vulnerable link

A plethora of nanoparticles are currently used in the food industry in myriad applications. Of these, ‘nanosilver’ is widely used due to their multitude actions. Recent consensus among the scientific community affirmed that nanosilver might potentially alter the gut microbiota instead of their intended use that has a profound effect on our health. Dysbiosis of gut microbiota led to the onset of serious pathological conditions as reflected from several studies. In lieu of the positive impact of nanosilver, their inadvertent toxic effects on gut microbiota are underestimated. In this review, first all studies concerning the influence of nanosilver on gut microbiota are discussed along with relevant pharmacokinetic studies and in closing section the challenges and future task remained in the field are highlighted.

Identification and Evaluation of Cytotoxicity of Peptide Liposome Incorporated Citron Extracts in an in Vitro System

Abstract: Citrons have been widely used for medicinal purposes for a long time, but the application of citron in the food industry is still restricted. The extensive advantages of nanotechnology in the food industry have greatly broadened the application of foods. In this study, by employing nanotechnology, we prepared citron-extract nanoparticle with an average size of 174.11 ± 3.89 nm, containing protein peptide and/or liposome. In order to evaluate the toxicity of nanoparticles and to ensure food safety, biological cytotoxicity at the cell and genomic levels was also identified to examine the toxicity of citron extracts by using an in vitro system. Our results demonstrated that the cytotoxicity of citron_liposome was dependent on cell type in high concentrations (1 and 5 mg/mL), selectively against primary human cardiac progenitor cells (hCPCs), and human endothelial progenitor cells (hEPCs) in MTT and lactate dehydrogenase (LDH) assays. Interestingly, for the NIH-3T3 and H9C2 cell lines, cell cytotoxicity was observed with slight genotoxicity, especially from citron_peptide extract for both cell lines. Taken together, our study provides cytotoxicity data on nanoengineered citron extracts according to different cell type as is crucial for further applications.

Cytotoxicity Evaluation of Turmeric Extract Incorporated Oil-in-Water Nanoemulsion

To overcome the drawbacks of conventional drug delivery system, nanoemulsion have been developed as an advanced form for improving the delivery of active ingredients. However, safety evaluation is crucial during the development stage before the commercialization. Therefore, the aim of this study was to evaluate the cytotoxicity of two types of newly developed nanoemulsions. Turmeric extract-loaded nanoemulsion powder-10.6 (TE-NEP-10.6, high content of artificial surfactant Tween 80), which forms the optimal nanoemulsion, and the TE-NEP-8.6 made by increasing the content of natural emulsifier (lecithin) to reduce the potential toxicity of nanoemulsion were cultured with various cells (NIH3T3, H9C2, HepG2, hCPC, and hEPC) and the changes of each cell were observed followed by nanoemulsion treatment. As a result, the two nanoemulsions (TE-NEP-10.6 and TE-NEP-8.6) did not show significant difference in cell viability. In the case of cell line (NIH3T3, H9C2, and HepG2), toxicity was not observed at an experimental concentration of less than 1 mg/mL, however, the cell survival rate decreased in a concentration dependent manner in the case of primary cultured cells. These results from our study can be used as a basic data to confirm the cell type dependent toxicity of nanoemulsion.

Extraction of Kaempferol and Its Glycosides Using Supercritical Fluids from Plant Sources: A Review

Research has focused on the study and design of new products containing phytochemicals (polyphenolic acids, flavonoids and anthocyanins, among others) that contribute to a better life quality for consumers, as well as techniques to improve the extraction of these compounds. In this regard, extraction with supercritical fluids (usually CO₂) is a technology that has better advantages than organic solvents, since lower temperatures that are used do not damage the product, and is more effective at high pressures. Extracts from plant sources contain significant concentrations of flavonols, one of the main compounds being kaempferol. Research has proven the antioxidant, anticarcinogenic, antidiabetic, cardioprotective, neuroprotective and antimicrobial properties of kaempferol and its glycosides. This review aims to present the main functional properties and extraction with supercritical fluids of kaempferol and its glycosides, as well as the application of this technology in the food area.

Current Demands for Food-Approved Liposome Nanoparticles in Food and Safety Sector

Safety of food is a noteworthy issue for consumers and the food industry. A number of complex challenges associated with food engineering and food industries, including quality food production and safety of the food through effective and feasible means can be explained by nanotechnology. However, nanoparticles have unique physicochemical properties compared to normal macroparticles of the same composition and thus could interact with living system in surprising ways to induce toxicity. Further, few toxicological/safety assessments have been performed on nanoparticles, thereby necessitating further research on oral exposure risk prior to their application to food. Liposome nanoparticles are viewed as attractive novel materials by the food and medical industries. For example, nanoencapsulation of bioactive food compounds is an emerging application of nanotechnology. In several food industrial practices, liposome nanoparticles have been utilized to improve flavoring and nutritional properties of food, and they have been examined for their capacity to encapsulate natural metabolites that may help to protect the food from spoilage and degradation. This review focuses on ongoing advancements in the application of liposomes for food and pharma sector.

INVESTIGATION OF THE INFLUENCE OF NANOPARTICLES OF METALS ON FERMENTTATION OF WORT OF HIGH CONCENTRATIONS

There was theoretically grounded and experimentally proved the expedience of enriching high-concentrated wort of the starch-containing raw material with such additional source of mineral nutrition for yeast cells as nanoparticles of metals. There was studied the influence of nanoparticles of metals on hydrolysis of biopolymers of the raw material and biosynthesis of organic compounds at wort fermentation. It was experimentally established, that the most positive influence of biosynthetic properties of yeast cells is realized by zinc and magnesium. At using zinc and magnesium, yeast biomass and alcohol content in mashes increase. Best chemical-technological indices of mashes were received at adding nanoparticles of zinc and magnesium at the stage of batch dilution. There was experimentally studied the synthesis of volatile organic admixtures in marsh distillates depending on point of adding nanoparticles of metals.

The effect of nano-silver packaging in increasing the shelf life of nuts: An in vitro model

Nano packaging is currently one of the most important topics in food packaging technologies. The aim of the application of this technology in food packaging is increasing shelf life of foods by preventing internal and external corruption and microbial contaminations. Use of silver nanoparticles in food packaging has recently attracted much attention. The aim of this study was to investigate the effect of nano-silver packaging in increasing the shelf life packages of nuts in an In vitro model. In this experimental study, the effects of different nano-silver concentrations (0, 1, 2 and 3 percent) on biological and chemical properties of 432 samples of nuts including walnuts, hazelnuts, almonds and pistachios were evaluated during 0, 3, 6, 9, 12, 15, 18, 21 and 24 months. In most samples, different concentrations of nano-silver (1, 2 and 3 %) significantly reduced total microbial count, mold and coliform counts compared to control group and the 3% nano-silver concentration was more effective than other concentrations (P<0.05). Moreover, using this packaging yielded an antioxidant effect especially when 2% and 3% nano-silver concentrations were used. Nano-silver also prevented growth of mold and so prevented aflatoxin production in all treatment groups. Results of chemical and biological tests showed that the silver nanoparticles had a significant effect on increasing the shelf life of nuts. The highest shelf life belonged to pistachios, almonds, hazelnuts and walnuts with 20, 19, 18 and 18 months, respectively. The shelf life was associated with amount of silver nanoparticles. The highest antimicrobial activity was observed when 3% nano-silver concentration was used in pistachios. The shelf life of control groups in similar storage conditions were calculated for an average of 13 months. In conclusion, the results of this study demonstrate the efficacy of nano-silver packing in increasing shelf life of nuts. Hence, use of nano-silver packaging in food industry, especially in food packaging is recommended.

The effects of innovative, consumer and social characteristics on willingness to try nano-foods

Purpose

By integrating the diffusion of innovation (DOI) theory, technology acceptance model (TAM), and social capital theory, the purpose of this paper is to: develop a model of consumer behavior and trial willingness toward nano-foods from product, consumer, and social perspectives; examine the effects of innovative features, consumer characteristics, and trust in authority on subjective perceptions (perceived trustworthiness and perceived benefit) as well as the social influence on attitudes toward nano-foods and trial willingness; examine the moderating role of product uncertainty on the relationship between these characteristics and subjective perceptions; and examine the effect of perceived benefit on perceived trustworthiness.

Design/methodology/approach

The results of the structural equation model (SEM), with nano-food knowledge data collected from 431 respondents, supported the research model and revealed the main effects hypothesized in this study and the moderating effect of product uncertainty. Simple slope analysis was further adopted to test the significant moderating effects.

Findings

The SEM results indicated that innovative characteristics (relative advantage, lack of observability, and novelty), consumer characteristics (perceived technology application), and social characteristics (trust in authority) affect perceived trustworthiness or perceived benefit. Social influence also has a direct effect on attitude toward nano-foods and trial willingness. Product uncertainty significantly moderates the relationship between characteristics (relative advantage and perceived technology application) and subjective perceptions (perceived trustworthiness and perceived benefit).

Research limitations/implications

With increasing numbers and kinds of nanotechnology products now being developed and sold, it is important to go further to determine consumer perceptions and attitudes toward these. This study, thus, applied the DOI, TAM, and social capital theory to examine this issue. However, other theories might also be used to carry out research from other perspectives. This study should, thus, be seen as preliminary, and it is hoped that more works will discuss consumer attitudes toward nanotechnology products in the future.

Practical implications

When a new nano-food is introduced, the current study suggests that food manufacturers use the description on the package as a communicative tool. Detailing the advantages of nano-foods on food packages might be a useful way to enhance trial willingness and to reduce the fears and insecurities related to the use of nano-related products. In addition, if food manufacturers could cooperate with organizations or individuals seen as having some authority in this area (e.g. nanotechnology researchers) in order to disseminate accurate information about nanotechnology and related food products, this might be an effective way to increase sales and profits.

Originality/value

This is the first paper integrating the DOI, the social capital theory and the TAM to empirically investigate consumer willingness to try nano-food products.

Titanium dioxide nanoparticles prime a specific activation state of macrophages

Titanium dioxide nanoparticles (TiO₂ NPs) are widely used in foods, cosmetics, and medicine. Although the inhalation toxicity of TiO₂ NPs has been studied, the potential adverse effects of oral exposure of low-dose TiO₂ NPs are largely unclear. Herein, with macrophage cell lines, primary cells, and mouse models, we show that TiO₂ NPs prime macrophages into a specific activation state characterized by excessive inflammation and suppressed innate immune function. After a month of dietary exposure in mice or exposure in vitro to TiO₂ NPs (10 and 50 nm), the expressions of pro-inflammatory genes in macrophages were increased, and the expressions of anti-inflammatory genes were decreased. In addition, for macrophages exposed to TiO₂ NPs in vitro and in vivo, their chemotactic, phagocytic, and bactericidal activities were lower. This imbalance in the immune system could enhance the susceptibility to infections. In mice, after a month of dietary exposure to low doses of TiO₂ NPs, an aggravated septic shock occurred in response to lipopolysaccharide challenge, leading to elevated levels of inflammatory cytokines in serum and reduced overall survival. Moreover, TLR4-deficient mice and primary macrophages, or TLR4-independent stimuli, showed less response to TiO₂ NPs. These results demonstrate that TiO₂ NPs induce an abnormal state of macrophages characterized by excessive inflammation and suppressed innate immune function in a TLR4-dependent manner, which may suggest a potential health risk, particularly for those with additional complications, such as bacterial infections.

p53, MAPKAPK-2 and caspases regulate nickel oxide nanoparticles induce cell death and cytogenetic anomalies in rats

The unique properties of nickel oxide nanoparticles (NiO-NPs) distinguish it from traditional nickel containing materials, and enable its industrial application as an advanced nanomaterial. Despite the benefits, the in vivo toxicological studies on NiO-NPs have been mainly focused on its pulmonary pathology. However, NiO-NPs exposure via oral route and its subsequent toxic effects in exposed animals are still lacking. Hence, we evaluated the NiO-NPs oral toxicity in male Wistar rats. NiO-NPs induced significant increase in chromosomal aberrations (CAs), micronuclei (MN) formation and, DNA damage in rats. Flow cytometric analysis showed apoptosis, ROS generation and dysfunction of mitochondrial membrane potential (ΔΨm). Imbalance of antioxidant enzymes, along with histological alterations was found in liver. Taking together, these results unequivocally suggested that NiO-NPs induced toxicity was through cyto-genetic alterations, oxidative stress, apoptosis and liver toxicity. The western blotting data validated the interplay of p53 and MAPKAPK-2 signalling via activation of caspases 8, 3, cyto c, pro-apoptotic bax and anti-apoptotic bcl-2 proteins.

Toxicological assessment of tungsten oxide nanoparticles in rats after acute oral exposure

Advances in and the rapid growth of the nanotechnology sector have escalated manufacture of nanoparticles (NPs), resulting in a significant increase in the probability of exposure of humans and wildlife to these materials. Many NPs have been found to exert genotoxicity. Therefore, genotoxicity studies are mandatory to assess the toxicity of NPs as a concern of succumbing to genetic diseases and cancers are universal. Tungsten oxide (WO₃) NPs are being explored extensively in various fields. However, the toxicological data of WO₃ NPs by oral route in mammals is limited. Hence, the goal of the current investigation was to evaluate the acute toxicity of WO₃ NPs and microparticles (MPs) after single oral administration with 100, 500 and 1000 mg/kg body weight doses in female Wistar rats. TEM, dynamic light scattering and laser Doppler velocimetry techniques were used to characterise the particles. The genotoxicity studies were conducted using comet, micronucleus and chromosomal aberration assays. Alterations in biochemical indices and metal distribution in various organs were also evaluated. The mean size of WO₃ NPs and MPs by TEM was 53.2 ± 1.91 nm and 5.17 ± 3.18 μm, respectively. The results revealed a significant increase in DNA damage and micronuclei and chromosomal aberrations after exposure to 1000 mg/kg dose of WO₃ NPs. Significant alterations in aspartate transaminase, alanine transaminase, reduced glutathione, catalase and malondialdehyde levels in serum and liver were found only at the higher dose of WO₃ NPs. Tungsten (W) biodistribution was observed in all the tissues in a dose-, time- and organ-dependent manner. In addition, the maximum concentration of W was found in the liver and the least in the brain was observed. The test substances were found to have a relatively low acute toxicity hazard. The data obtained gives preliminary information on the potential toxicity of WO₃ NPs and MPs.

Synergistic toxicity of zno nanoparticles and dimethoate in mice: Enhancing their biodistribution by synergistic binding of serum albumin and dimethoate to zno nanoparticles

The extensive applications of ZnO nanoparticles (nano ZnO) and dimethoate (DM) have increased the risk of humans' co-exposure to nano ZnO and DM. Here, we report the synergistic effect of nano ZnO and DM on their biodistribution and subacute toxicity in mice. Nano ZnO and DM had a synergistic toxicity in mice. In contrast, bulk ZnO and DM did not cause an obvious synergistic toxicity in mice. Although nano ZnO was low toxic to mice, coexposure to nano ZnO and DM significantly enhanced DM-induced oxidative damage in the liver. Coadministration of nano ZnO with DM significantly increased Zn accumulation by 30.9 ± 1.9% and DM accumulation by 45.6 ± 2.2% in the liver, respectively. The increased accumulations of DM and Zn in the liver reduced its cholinesterase activity from 5.65 ± 0.32 to 4.37 ± 0.49 U/mg protein and induced hepatic oxidative stress. Nano ZnO had 3-fold or 2.4-fold higher binding capability for serum albumin or DM, respectively, than bulk ZnO. In addition, serum albumin significantly increased the binding capability of nano ZnO for DM by approximately four times via the interaction of serum albumin and DM. The uptake of serum albumin- and DM-bound nano ZnO by the macrophages significantly increased DM accumulation in mice. Serum albumins play an important role in the synergistic toxicity of nano ZnO and DM. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1202-1212, 2017.

Prenatal exposure to nanosized zinc oxide in rats: neurotoxicity and postnatal impaired learning and memory ability

AIM

To examine the neurotoxicity of prenatal exposure to ZnO nanoparticles on rat offspring.

MATERIALS & METHODS

Pregnant Sprague-Dawley rats were exposed to ZnO nanoparticles (NPs) by gavage. Toxicity was assessed including zinc biodistribution, cerebral histopathology, antioxidant status and learning and memory capability.

RESULTS

A significantly elevated concentration of zinc was detected in offspring brains. Transmission electron microscope observations showed abnormal neuron ultrastructures. Histopathologic changes such as decreased proliferation and higher apoptotic death were observed. An obvious imbalanced antioxidant status occurred in brains. Adult experimental offspring exhibited impaired learning and memory behavior in the Morris water maze test compared with control groups.

CONCLUSION

These adverse effects on offspring brain may cause impaired learning and memory capabilities in adulthood, particularly in female rats.

Nanotechnology to the rescue: using nano-enabled approaches in microbiological food safety and quality

Food safety and quality assurance is entering a new era. Interventions along the food supply chain must become more efficient in safeguarding public health and the environment and must address numerous challenges and new consumption trends. Current methods of microbial control to assure the safety of food and minimize microbial spoilage have each shown inefficiencies. Nanotechnology is a rapidly expanding area in the agri/feed/food sector. Nano-enabled approaches such as antimicrobial food-contact surfaces/packaging, nano-enabled sensors for rapid pathogen/contaminant detection and nano-delivered biocidal methods, currently on the market or at a developmental stage, show great potential for the food industry. Concerns on potential risks to human health and the environment posed by use of engineered nanomaterials (ENMs) in food applications must, however, be adequately evaluated at the developmental stage to ensure consumer's acceptance.

Titanium Dioxide Nanoparticle-Biomolecule Interactions Influence Oral Absorption

Titanium dioxide (TiO₂) nanoparticles (NPs) have been widely applied in various industrial fields, such as electronics, packaging, food, and cosmetics. Accordingly, concerns about the potential toxicity of TiO₂ NPs have increased. In order to comprehend their in vivo behavior and potential toxicity, we must evaluate the interactions between TiO₂ NPs and biomolecules, which can alter the physicochemical properties and the fate of NPs under physiological conditions. In the present study, in vivo solubility, oral absorption, tissue distribution, and excretion kinetics of food grade TiO₂ (f-TiO₂) NPs were evaluated following a single-dose oral administration to rats and were compared to those of general grade TiO₂ (g-TiO₂) NPs. The effect of the interactions between the TiO₂ NPs and biomolecules, such as glucose and albumin, on oral absorption was also investigated, with the aim of determining the surface interactions between them. The intestinal transport pathway was also assessed using 3-dimensional culture systems. The results demonstrate that slightly higher oral absorption of f-TiO₂ NPs compared to g-TiO₂ NPs could be related to their intestinal transport mechanism by microfold (M) cells, however, most of the NPs were eliminated through the feces. Moreover, the biokinetics of f-TiO₂ NPs was highly dependent on their interaction with biomolecules, and the dispersibility was affected by modified surface chemistry.

Biokinetics of food additive silica nanoparticles and their interactions with food components

Nanomaterials have been widely utilized in the food industry in production, packaging, sensors, nutrient delivery systems, and food additives. However, research on the interactions between food-grade nanoparticles and biomolecules as well as their potential toxicity is limited. In the present study, the in vivo solubility, oral absorption, tissue distribution, and excretion kinetics of one of the most extensively used food additives, silica (SiO₂) were evaluated with respect to particle size (nano vs bulk) following single-dose oral administration to rats. Intestinal transport mechanism was investigated using a 3D culture system, in vitro model of human intestinal follicle-associated epithelium (FAE). The effect of the presence of food components, such as sugar and protein, on the oral absorption of nanoparticles was also evaluated with focus on their interactions. The results obtained demonstrated that the oral absorption of nanoparticles (3.94±0.38%) was greater than that of bulk materials (2.95±0.37%), possibly due to intestinal transport by microfold (M) cells. On the other hand, particle size was found to have no significant effect on in vivo dissolution property, biodistribution, or excretion kinetics. Oral absorption profile of silica nanoparticles was highly dependent on the presence of sugar or protein, showing rapid absorption rate in glucose, presumably due to their surface interaction on nanoparticles. These findings will be useful for predicting the potential toxicity of food-grade nanoparticles and for understanding biological interactions.

Comparative toxicity and biodistribution assessments in rats following subchronic oral exposure to copper nanoparticles and microparticles

Background

Copper nanoparticles (Cu NPs) have great potential in electronics and biomedical fields because of their efficient thermodynamic and anti-microbial properties. However, their potential toxic effects and kinetic data following repeated exposure are still unclear.

Methods

We evaluated the physicochemical properties of Cu NPs (25 nm) and copper microparticles (Cu MPs, 14–25 μm). Comparative in vivo toxicity of Cu NPs and Cu MPs was evaluated by conducting a 28-day repeated oral dose study at equivalent dose levels of 0, 100, 200, and 400 mg/kg/day (vehicle, 1 % hydroxypropyl methylcellulose). We determined Cu levels in the blood, tissues, urine, and feces by using inductively coupled plasma mass spectrometry.

Results

The solubility of Cu NPs and Cu MPs was 84.5 and 17.2 %, respectively, in an acidic milieu; however, they scarcely dissolved in vehicle or intestinal milieus. The specific surface area of Cu NPs and Cu MPs was determined to be 14.7 and 0.16 m²/g, respectively. Cu NPs exhibited a dose-dependent increase of Cu content in the blood and tested organs, with particularly high levels of Cu in the liver, kidney, and spleen. Only for liver and kidney increased Cu levels were found in Cu MPs-treated rats. Cu NPs caused a dose-related increase in Cu levels in urine, whereas Cu MPs did not affect the urine Cu levels. Extremely high levels of Cu were detected in the feces of Cu MPs-treated rats, whereas much lower levels were detected in the feces of Cu NPs-treated rats. A comparative in vivo toxicity study showed that Cu NPs caused damages to red blood cells, thymus, spleen, liver, and kidney at ≥200 mg/kg/days, but Cu MPs did not cause any adverse effects even at the highest dose.

Conclusions

Overall, the in vivo repeated dose toxicity study of Cu NPs and Cu MPs demonstrated that large surface area and high solubility in physiological milieus could directly influence the toxicological responses and biodistribution of Cu particles when administered orally. Under these experimental conditions, the no-observed-adverse-effect levels of Cu NPs and Cu MPs were determined to be 100 and ≥400 mg/kg/day, respectively.

Electronic supplementary material

The online version of this article (doi:10.1186/s12989-016-0169-x) contains supplementary material, which is available to authorized users.

Transformation of food packaging from passive to innovative via nanotechnology: concepts and critiques

In recent decades, there is a global advancement in manufacturing industry due to increased applications of nanotechnology. Food industry also has been tremendously changing from passive packaging to innovative packaging, to cope with global trends, technological advancements, and consumer preferences. Active research is taking place in food industry and other scientific fields to develop innovative packages including smart, intelligent and active food packaging for more effective and efficient packaging materials with balanced environmental issues. However, in food industry the features behind smart packaging are narrowly defined to be distinguished from intelligent packaging as in other scientific fields, where smart materials are under critical investigations. This review presents some scientific concepts and features pertaining innovative food packaging. The review opens new research window in innovative food packaging to cover the existing disparities for further precise research and development of food packaging industry.

Preparation and Characterization of Mucoadhesive Buccal Nanoparticles Using Chitosan and Dextran Sulfate

The aim of this study was to formulate buccal mucoadhesive nanoparticles (NPs) using the natural mucoadhesive polymers. The natural mucoadhesive polymers chitosan (CS) and dextran sulfate sodium salt (DS) were used to prepare mucoadhesive NPs using the ionic gelation method. As the molecular weight of DS decreased, the amount of mucin and the number of buccal cells adsorbed on DS increased. The CS/DS NPs ranged from 100 to 200 nm in diameter. The adhesive interactions of CS/DS NPs with mucin were not significantly different from those of CS/sodium triphosphate pentabasic (TPP) NPs; however, CS/DS NPs exhibited 5 times greater mucoadhesive activity to buccal cells compared to control CS/TPP NPs in ex vivo adhesion tests. These results indicate that the buccal mucoadhesive properties of NPs can be improved using natural mucoadhesive polymers.

Comparative toxicity and biodistribution of copper nanoparticles and cupric ions in rats

Despite widespread use and prospective biomedical applications of copper nanoparticles (Cu NPs), their biosafety issues and kinetics remain unclear. Thus, the aim of this study was to compare the detailed in vivo toxicity of Cu NPs and cupric ions (CuCl₂; Cu ions) after a single oral dose. We determined the physicochemical characteristics of Cu NPs, including morphology, hydrodynamic size, zeta potential, and dissolution in gastric (pH 1.5), vehicle (pH 6.5), and intestinal (pH 7.8) conditions. We also evaluated the kinetics of Cu following a single equivalent dose (500 mg/kg) of Cu NPs and Cu ions. Cu NPs had highest dissolution (84.5%) only in gastric conditions when compared with complete dissolution of Cu ions under various physiological milieus. Kinetic analysis revealed that highest Cu levels in blood and tested organs of Cu NP-treated rats were 15%–25% lower than that of Cu ions. Similar to the case of Cu ions, Cu levels in the tested organs (especially liver, kidney, and spleen) of Cu NP-treated rats increased significantly when compared with the vehicle control. However, delay in reaching the highest level and biopersistence of Cu were observed in the blood and tested organs of Cu NP-treated rats compared with Cu ions. Extremely high levels of Cu in feces indicated that unabsorbed Cu NPs or absorbed Cu ions were predominantly eliminated through liver/feces. Cu NPs exerted apparent toxicological effects at higher dose levels compared with Cu ions and showed sex-dependent differences in mortality, biochemistry, and histopathology. Liver, kidney, and spleen were the major organs affected by Cu NPs. Collectively, the toxicity and kinetics of Cu NPs are most likely influenced by the release of Cu dissociated from Cu NPs under physiological conditions.

Titanium Dioxide Particle Type and Concentration Influence the Inflammatory Response in Caco-2 Cells

Titanium dioxide (TiO₂) nanoparticles are widely used in cosmetics, sunscreens, biomedicine, and food products. When used as a food additive, TiO₂ nanoparticles are used in significant amounts as white food-coloring agents. However, the effects of TiO₂ nanoparticles on the gastrointestinal tract remain unclear. The present study was designed to determine the effects of five TiO₂ particles of different crystal structures and sizes in human epithelial colorectal adenocarcinoma (Caco-2) cells and THP-1 monocyte-derived macrophages. Twenty-four-hour exposure to anatase (primary particle size: 50 and 100 nm) and rutile (50 nm) TiO₂ particles reduced cellular viability in a dose-dependent manner in THP-1 macrophages, but in not Caco-2 cells. However, 72-h exposure of Caco-2 cells to anatase (50 nm) TiO₂ particles reduced cellular viability in a dose-dependent manner. The highest dose (50 µg/mL) of anatase (100 nm), rutile (50 nm), and P25 TiO₂ particles also reduced cellular viability in Caco-2 cells. The production of reactive oxygen species tended to increase in both types of cells, irrespective of the type of TiO₂ particle. Exposure of THP-1 macrophages to 50 µg/mL of anatase (50 nm) TiO₂ particles increased interleukin (IL)-1β expression level, and exposure of Caco-2 cells to 50 µg/mL of anatase (50 nm) TiO₂ particles also increased IL-8 expression. The results indicated that anatase TiO₂ nanoparticles induced inflammatory responses compared with other TiO₂ particles. Further studies are required to determine the in vivo relevance of these findings to avoid the hazards of ingested particles.

Genotoxic effects of chromium oxide nanoparticles and microparticles in Wistar rats after 28 days of repeated oral exposure

The nanotechnology industry has advanced rapidly in the last 10 years giving rise to the growth of the nanoparticles (NPs) with great potential in various arenas. However, the same properties that make NPs interesting raise concerns because their toxicity has not been explored. The in vivo toxicology of chromium oxide (Cr2O3)-NPs is not known till date. Therefore, this study investigated the 28-day repeated toxicity after 30, 300 and 1000 mg/kg body weight (bw)/day oral treatment with Cr2O3-NPs and Cr2O3 microparticles (MPs) in Wistar rats. The mean size of Cr2O3-NPs and Cr2O3-MPs was 34.89 ± 2.65 nm and 3.76 ± 3.41 μm, respectively. Genotoxicity was assessed using comet, micronucleus and chromosomal aberration (CA) assays. The results revealed a significant increase in DNA damage in peripheral blood leucocytes and liver, micronuclei and CA in bone marrow after exposure of 300 and 1000 mg/kg doses of Cr2O3-NPs and Cr2O3-MPs only at 1000 mg/kg bw/day. Cr biodistribution was observed in all the tissues in a dose-dependent manner. The maximum amount of Cr was found in the kidneys and least in the brain of the treated rats. More of the Cr was excreted in the faeces than in the urine. Furthermore, nanotreated rats displayed much higher absorption and tissue accumulation. These findings provide initial data of the probable genotoxicity and biodistribution of NPs and MPs of Cr2O3 generated through repeated oral treatment.

Application of Response Surface Methodology for Optimization of Urea Grafted Multiwalled Carbon Nanotubes in Enhancing Nitrogen Use Efficiency and Nitrogen Uptake by Paddy Plants

Efficient use of urea fertilizer (UF) as important nitrogen (N) source in the world’s rice production has been a concern. Carbon-based materials developed to improve UF performance still represent a great challenge to be formulated for plant nutrition. Advanced N nanocarrier is developed based on functionalized multiwall carbon nanotubes (f-MWCNTs) grafted with UF to produce urea-multiwall carbon nanotubes (UF-MWCNTs) for enhancing the nitrogen uptake (NU) and use efficiency (NUE). The grafted N can be absorbed and utilized by rice efficiently to overcome the N loss from soil-plant systems. The individual and interaction effect between the specified factors of f-MWCNTs amount (0.10–0.60 wt%) and functionalization reflux time (12–24 hrs) with the corresponding responses (NUE, NU) were structured via the Response Surface Methodology (RSM) based on five-level CCD. The UF-MWCNTs with optimized 0.5 wt% f-MWCNTs treated at 21 hrs reflux time achieve tremendous NUE up to 96% and NU at 1180 mg/pot. Significant model terms (pvalue < 0.05) for NUE and NU responses were confirmed by the ANOVA. Homogeneous dispersion of UF-MWCNTs was observed via FESEM and TEM. The chemical changes were monitored by FT-IR and Raman spectroscopy. Hence, this UF-MWCNTs’ approach provides a promising strategy in enhancing plant nutrition for rice.

Nanotechnology: a future tool to improve quality and safety in meat industry

Nanotechnology refers to the new aspect of science modifies its physical, chemical and biological properties leading to new applications or enhanced utility. Keeping the pace with other industries, the meat industry has adopted the new technology in a range of applications to improve the quality and safety of products. The potential applications include the improvement in the tastes, texture, flavor, production of low fat and salt products, enhanced nutrient absorption, improved packaging techniques and better pathogen detection system. However some safety issues need to be addressed before taking a ride on the technology at the full throttle.

Physicochemical and toxicological evaluation of silica nanoparticles suitable for food and consumer products collected by following the EC recommendation

Specific information about the particle size distribution, agglomeration state, morphology, and chemical composition of four silica samples, used as additives in food and in personal care products, were achieved with a combination of analytical techniques. The combined use of differential centrifugal sedimentation (DCS), sedimentation field flow fractionation (SdFFF), and scanning and transmission electron microscopy (SEM and TEM) allows to classify the water dispersed samples as "nanomaterials" according to the EC definition. The mechanical stirring and the ultrasound treatment were compared as dispersion methods. The particle surface chemical composition, determined by particle-induced X-ray emission (PIXE) and X-ray photoelectron spectroscopy (XPS), assessed the different levels of purity between the pyrogenic and the precipitated silica and highlighted particle surface chemical composition modifications in the outer shell when dispersed by mechanical stirring. The potential toxic effects of silica on intestinal Caco-2 cells were investigated using MTS assay and by measuring lactate dehydrogenase (LDH) release and caspases 3/7 activity after 24 h of incubation. No or limited decrease of cell viability was observed for all particles regardless of dispersion procedure, suggesting a relative innocuity of these silica samples.