Effects Of Nanoparticle Exposure Research Articles

Effects of titanium dioxide (TiO2)/activated carbon (AC) nanoparticle on the growth and immunity of the giant freshwater prawn, Macrobrachium rosenbergii: potential toxicological risks to the aquatic crustaceans.

Due to their unique physicochemical characteristics, nanomaterials exhibit many excellent properties and functions, leading to their applications in numerous fields. The large-scale production and widespread application of nanomaterials have inevitably resulted in their release into the environment, especially the water environment. Several studies have confirmed that exposure to nanomaterials can be toxic to aquatic organisms. However, few studies have focused on the effects of nanomaterial exposure on growth and immunity in crustaceans. In the present study, juvenile Macrobrachium rosenbergii were exposed to different concentrations of titanium dioxide (TiO2)/activated carbon (AC) composite nanomaterial (0.1 and 0.5mg/L) for 45days. The effects of nanoparticle exposure on digestion and antioxidant-related enzyme activities, as well as the expression of growth and immunity-related genes and signaling pathway, were evaluated. Our results show that in response to low concentration of TiO2/AC nanoparticle (0.1mg/L), most of the enzyme activities related to digestion and antioxidation (TPS, LPS, AMS, SOD, and CAT) were diminished. On the contrary, the GSH-Px activity increased under the 0.1mg/L group of TiO2/AC nanoparticle concentration. Additionally, the level of digestive and antioxidant enzyme activities we detected was increased when exposed to 0.5mg/L TiO2/AC nanoparticle. By comparison to the expression level of growth-related genes in the control group, MSTN, CaBP, E75, Raptor, EcR, and EGF were significantly inhibited at 0.1 and 0.5mg/L concentrations of TiO2/AC nanoparticle, whereas the expression level of genes (TLR, JAK, STAT, PPAF, ACP, and AKP) related to immunity was increased when exposed to different concentrations of TiO2/AC nanoparticle. Compared with the control group (0mg/L concentration), 5166 DEGs were identified in the TiO2/AC nanoparticle group, and a large number of DEGs were involved in molting, energy metabolism, stress tolerance, and germ cell development. Moreover, KEGG analysis revealed that many DEGs were assigned into signaling pathways related to metabolic growth and immune stress. These results showed that exposure to TiO2/AC nanoparticle will result in the changes of enzyme activity and routine mRNA expression, suggesting that TiO2/AC nanoparticle which existed in aquatic environment might affect the physiology of M. rosenbergii. This study will provide significant information for the evaluation of nanomaterial toxicity on aquatic crustaceans.

Effects of Workers Exposure to Nanoparticles Studied by NMR Metabolomics

In this study, the effects of occupational exposure to nanoparticles (NPs) were studied by NMR metabolomics. Exhaled breath condensate (EBC) and blood plasma samples were obtained from a research nanoparticles-processing unit at a national research university. The samples were taken from three groups of subjects: samples from workers exposed to nanoparticles collected before and after shift, and from controls not exposed to NPs. Altogether, 60 1H NMR spectra of exhaled breath condensate (EBC) samples and 60 1H NMR spectra of blood plasma samples were analysed, 20 in each group. The metabolites identified together with binning data were subjected to multivariate statistical analysis, which provided clear discrimination of the groups studied. Statistically significant metabolites responsible for group separation served as a foundation for analysis of impaired metabolic pathways. It was found that the acute effect of NPs exposure is mainly reflected in the pathways related to the production of antioxidants and other protective species, while the chronic effect is manifested mainly in the alteration of glutamine and glutamate metabolism, and the purine metabolism pathway.

Effect of nanoparticle exposure in a living system: probed by quantification of Fetuin-B in plasma proteome and kidney tissue imaging using MALDI imaging mass spectrometry in a rat model

Effect of nanoparticle exposure in a living system: probed by quantification of Fetuin-B in plasma proteome and kidney tissue imaging using MALDI imaging mass spectrometry in a rat model

DNA Methylation Profiles in a Group of Workers Occupationally Exposed to Nanoparticles.

The risk of exposure to nanoparticles (NPs) has rapidly increased during the last decade due to the vast use of nanomaterials (NMs) in many areas of human life. Despite this fact, human biomonitoring studies focused on the effect of NP exposure on DNA alterations are still rare. Furthermore, there are virtually no epigenetic data available. In this study, we investigated global and gene-specific DNA methylation profiles in a group of 20 long-term (mean 14.5 years) exposed, nanocomposite, research workers and in 20 controls. Both groups were sampled twice/day (pre-shift and post-shift) in September 2018. We applied Infinium Methylation Assay, using the Infinium MethylationEPIC BeadChips with more than 850,000 CpG loci, for identification of the DNA methylation pattern in the studied groups. Aerosol exposure monitoring, including two nanosized fractions, was also performed as proof of acute NP exposure. The obtained array data showed significant differences in methylation between the exposed and control groups related to long-term exposure, specifically 341 CpG loci were hypomethylated and 364 hypermethylated. The most significant CpG differences were mainly detected in genes involved in lipid metabolism, the immune system, lung functions, signaling pathways, cancer development and xenobiotic detoxification. In contrast, short-term acute NP exposure was not accompanied by DNA methylation changes. In summary, long-term (years) exposure to NP is associated with DNA epigenetic alterations.

High-Throughput Screening for Engineered Nanoparticles That Enhance Photosynthesis Using Mesophyll Protoplasts.

Certain engineered nanoparticles (NPs) have unique properties that have exhibited significant potential for promoting photosynthesis and enhancing crop productivity. Understanding the fundamental interactions between NPs and plants is crucial for the sustainable development of nanoenabled agriculture. Leaf mesophyll protoplasts, which maintain similar physiological response and cellular activity as intact plants, were selected as a model system to study the impact of NPs on photosynthesis. The mesophyll protoplasts isolated from spinach were cultivated with different NMs (Fe, Mn3O4, SiO2, Ag, and MoS2) dosing at 50 mg/L for 2 h under illumination. The potential maximum quantum yield and adenosine triphosphate (ATP) production of mesophyll protoplasts were significantly increased by Mn3O4 and Fe NPs (23% and 43%, respectively), and were decreased by Ag and MoS2 NPs. The mechanism for the photosynthetic enhancement by Mn3O4 and Fe is to increase the photocurrent and electron transfer rate, as revealed by photoelectrochemical measurement. GC-MS based single cell type metabolomics reveal that NPs (Fe and MoS2) altered the metabolic profiles of mesophyll cells during 2 h of illumination period. Separately, the effect of NPs exposure on photosynthesis and biomass were also conducted at the whole plant level. A strong correlation was observed with protoplast data; plant biomass was significantly increased by Mn3O4 exposure (57%) but was decreased (24%) by treatment of Ag NPs. The use of mesophyll protoplasts can be a fast and reliable tool for screening NPs to enhance photosynthesis for potential nanofertilizer use. Importantly, inclusion of a metabolic analysis can provide mechanistic toxicity data to ensure the development "safer-by-design" nanoenabled platforms.

Influence of Nano-ZnO Exposure to Plants on L-Ascorbic Acid Levels: Indication of Nanoparticle-Induced Oxidative Stress.

With the continuously growing production of nanomaterials, their presence in the environment increases. The effects of nanoparticle exposure on plants are yet not fully understood. This study aimed to provide new insights into the stress induced by the exposure of plants to nanoparticles via the determination of the content of L-ascorbic acid, known antioxidant, in the samples of bryophyte species Pleurozium schreberi (Brid.) Mitt. Bryophyte samples, collected from a pristine environment, were exposed to 0.1 g·L-1 suspensions of nano-ZnO for five weeks. Prior to the exposure, the samples were subjected to the combination of treatments-washing or not washing as well as drying or irrigation. In order to assess the level of oxidative stress caused by the exposure to the ZnO nanoparticles under various pre-treatment conditions, the content of the L-ascorbic acid in the samples was determined by titration with dichlorophenolindophenol. Effect of both nano-ZnO exposure and pre-treatment was observed; nano-ZnO exposure significantly reduced the content of L-ascorbic acid in the bryophyte samples indicating it being consumed in the repair processes following the exposure-related physiological stress.

Monitoring the environmental effects of CeO2 and ZnO nanoparticles through the life cycle of corn (Zea mays) plants and in situ μ-XRF mapping of nutrients in kernels.

Information about changes in physiological and agronomic parameters through the life cycle of plants exposed to engineered nanoparticles (NPs) is scarce. In this study, corn (Zea mays) plants were cultivated to full maturity in soil amended with either nCeO2 or nZnO at 0, 400, and 800 mg/kg. Gas exchange was monitored every 10 days, and at harvest, bioaccumulation of Ce and Zn in tissues was determined by ICP-OES/MS. The effects of NPs exposure on nutrient concentration and distribution in ears were also evaluated by ICP-OES and μ-XRF. Results showed that nCeO2 at both concentrations did not impact gas exchange in leaves at any growth stage, while nZnO at 800 mg/kg reduced net photosynthesis by 12%, stomatal conductance by 15%, and relative chlorophyll content by 10% at day 20. Yield was reduced by 38% with nCeO2 and by 49% with nZnO. Importantly, μ-XRF mapping showed that nCeO2 changed the allocation of calcium in kernels, compared to controls. In nCeO2 treated plants, Cu, K, Mn, and Zn were mainly localized at the insertion of kernels into cobs, but Ca and Fe were distributed in other parts of the kernels. Results showed that nCeO2 and nZnO reduced corn yield and altered quality of corn.

Occupational and Environmental Health Effects of Nanomaterials.

With the recent advancements in nanosciences and nanotechnologies, a large number of novel nanomaterials have been introduced in our everyday life. However, as the potential hazards of these novel nanomaterials have not yet been fully understood, concerns on their occupational and environmental health effects are mounting. In fact, recent scientific studies suggested that at least some nanoparticles actively interact with biological tissues and cause toxicological effects on the experimental animals exposed to these materials. Current research also indicates that the toxicity of manufactured nanomaterials will depend on their physical and chemical properties including their chemical composition, core size, morphology, agglomeration state, surface area, and surface charge. However, so far, quantitative understanding on the relationships between their physicochemical properties, biological toxicities, and human and environmental health effects is lacking. It is therefore imperative to have a clearer understanding of such a relationship and hence the aim of this special issue is to discuss occupational and environmental health effects of nanomaterials in relation to their various physicochemical properties. Several authors participated in this special issue to present their understanding on occupational and environmental health effects of nanomaterials. “Three-Day Continuous Exposure Monitoring of CNT Manufacturing Workplaces” by J. H. Lee et al. and “Workplace Exposure to Titanium Dioxide Nanopowder Released from a Bag Filter System” by J. H. Ji et al. are related to occupational safety and health of nanomaterial and deal with exposure assessment in the workplaces producing or handling manufactured nanomaterials. The authors of these two papers actively monitored exposure situations in the workplaces where nanomaterial manufacturing and handling were conducted and presented workers' exposure situation and exposure mitigation strategies. “Aquatic Toxicity Comparison of Silver Nanoparticles and Silver Nanowires” by E. K. Sohn et al. and “Multiwall Carbon Nanotube-Induced Apoptosis and Antioxidant Gene Expression in the Gills, Liver, and Intestine of Oryzias latipes” by J. W. Lee et al. are dealing with aquatic toxicity of one-dimensional form of nanomaterial such as wire or fiber form. E. K. Sohn et al. compared aquatic toxicity of particular forms with wire forms of nanomaterials and J. W. Lee et al. found that the gills were more sensitive to MWCNT toxicity than the other organs with gender difference and caused apoptosis with relevant gene expressions increasing caspases, while reducing expression of catalase and GST genes. Y.-H. Luo et al. studied immunotoxicity of metal-based nanoparticles showing different toxicokinetics from conventional bulk nonnanoscale materials depending on their physicochemical properties. In the paper entitled “Metal-Based Nanoparticles and the Immune System: Activation, Inflammation, and Potential Applications,” a discussion is presented on nanoparticle and innate immunity and effect of nanoparticle exposure on toll-like receptor signaling and on their role in innate immune system and effect of nanoparticle exposure on adaptive immunity. Currently, there is limited evidence on human hazards due to nanomaterial exposure. This is partly due to the very few numbers of workers or consumers exposed to nanomaterial as well as limited epidemiological or biomonitoring tools to evaluate human health hazards caused by nanomaterial exposure. L. Cabalova et al. studied micro- and nanosized particles using scanning electron microscopy and Raman microscopy in nasal mucosa from patients with chronic hypertrophic rhinosinusitis and obtained the mucosa of the inferior nasal turbinates, which are the deposition site of inhaled particles and the first barrier filtering the inhaled air. Their pilot study suggested possibility of quantification of distribution of micro- and nanosized particles in tissue samples. Their results give some promising methods by which to investigate nanoparticle exposure in human population. Nanomaterial measurement and characterization method using superresolution stimulated emission depletion (STED) microscopy presented a new method in the evaluation of nanoparticle interaction mechanisms on a cellular level. They demonstrated quantitative estimates of the number of nanoparticles administered, delivered, and internalized by epithelial cells which can be extracted from 3D STED image stacks of entire cells via image processing. This method would provide understanding on essential knowledge for risk assessment and safe design approaches in nanotechnology.

Effect of Nanoparticles Exposure on Fractional Exhaled Nitric Oxide (FENO) in Workers Exposed to Nanomaterials

Fractional exhaled nitric oxide (FENO) measurement is a useful diagnostic test of airway inflammation. However, there have been few studies of FENO in workers exposed to nanomaterials. The purpose of this study was to examine the effect of nanoparticle (NP) exposure on FENO and to assess whether the FENO is increased in workers exposed to nanomaterials (NM). In this study, both exposed workers and non-exposed controls were recruited from NM handling plants in Taiwan. A total of 437 subjects (exposed group = 241, non-exposed group = 196) completed the FENO and spirometric measurements from 2009–2011. The authors used a control-banding (CB) matrix to categorize the risk level of each participant. In a multivariate linear regression analysis, this study found a significant association between risk level 2 of NP exposure and FENO. Furthermore, asthma, allergic rhinitis, peak expiratory flow rate (PEFR), and NF-κB were also significantly associated with FENO. When the multivariate logistic regression model was adjusted for confounders, nano-TiO2 in all of the NM exposed categories had a significantly increased risk in FENO > 35 ppb. This study found associations between the risk level of NP exposure and FENO (particularly noteworthy for Nano-TiO2). Monitoring FENO in the lung could open up a window into the role nitric oxide (NO) may play in pathogenesis.

Pilot study on effects of nanoparticle exposure on Crassostrea virginica hemocyte phagocytosis

Little is known about engineered nanoparticles (NPs) exposures on oysters. As sessile filter feeders, oysters are likely to be exposed to NPs suspended in the water column with unknown effects of NP exposure on oyster functioning. Our study indicates that waterborne NPs alter oyster hemocyte phagocytosis dynamics, an indication of sub-lethal effects of NP exposures. Silver NPs, titanium dioxide (TiO2) NPs, and silver nitrate exposures reduced phagocytosis compared to the control. Increasing TiO2 NPs and silver nitrate concentrations reduced phagocytosis. Silver NPs, up to 120ppb, increased phagocytosis, but higher concentrations reduced phagocytosis.

Effect of exposure conditions on SWCNT-induced inflammatory response in human alveolar epithelial cells

There has been an increasing interest in the development and applications of carbon nanotubes (CNTs) due to their huge potential in industrial and medical applications, but the toxicological properties of these materials have not been well characterized, especially the effects of nanoparticle exposure under different conditions on cellular responses. Nano-structured particles are potentially hazardous when they deposit in the respiratory system. In this study, we characterized the effects of single walled CNT (SWCNT) exposure on interleukin-8 (IL-8) expression in human alveolar epithelial cells (A549) under various exposure conditions. We measured the level of IL-8 expression in the presence and absence of serum following exposure of SWCNTs. The results demonstrated that IL-8 expression was enhanced in the presence of serum. When A549 cells were exposed to low concentrations of SWCNTs, IL-8 expression kept increasing, even after removal of SWCNTs from the media. In addition, SWCNT exposure under dynamic cell growth condition induced changes in IL-8 expression.

Effects of Titanium Dioxide Nanoparticle Exposure on Neuroimmune Responses in Rat Airways

Exposure to ambient nanoparticles (defined as particulate matter [PM] having one dimension <100 nm) is associated with increased risk of childhood and adult asthma. Nanomaterials feature a smaller aerodynamic diameter and a higher surface area per unit mass ratio compared to fine or coarse-sized particles, resulting in greater lung deposition efficiency and an increased potential for biological interaction. The neurotrophins nerve growth factor and brain-derived neurotrophic factor are key regulatory elements of neuronal development and responsiveness of airway sensory neurons. Changes in their expression are associated with bronchoconstriction, airway hyperresponsiveness, and airway inflammation. The neurogenic-mediated control of airway responses is a key pathophysiological mechanism of childhood asthma. However, the effects of nanoparticle exposure on neurotrophin-driven airway responses and their potential role as a predisposing factor for developing asthma have not been clearly elucidated. In this study, in vivo inhalation exposure to titanium dioxide nanoparticles (12 mg/m3; 5.6 h/d for 3 d) produced upregulation of lung neurotrophins in weanling (2-wk-old) and newborn (2-d-old) rats but not in adult (12-wk-old) animals compared to controls. This effect was associated with increased airway responsiveness and upregulation of growth-related oncogene/keratine-derived chemokine (GRO/KC; CXCL1, rat equivalent of human interleukin [IL]-8) in bronchoalveolar lavage fluid. These data show for the first time that exposure to nanoparticulate upregulates the expression of lung neurotrophins in an age-dependent fashion and that this effect is associated with airway hyperresponsiveness and inflammation. These results suggest the presence of a critical window of vulnerability in earlier stages of lung development, which may lead to a higher risk of developing asthma.

Nanotechnology-Related Environment, Health, and Safety Research: Examining the National Strategy

Pick up a tube of sunscreen, a tennis racquet, an iPod, or any number of other consumer products, and there’s a good chance that it’s been “nano-enabled,” meaning it contains nanoscale particles designed to give it some beneficial feature. An estimated $147 billion worth of nano-enabled commercial and consumer products were sold in 2007, according to Lux Research, a market analysis firm in New York City. Citing the firm’s latest estimates, Lux analyst David Hwang predicts that figure could top $3.1 trillion by 2015, reinforcing a broad view that nanotechnology is fueling a new industrial revolution. Yet nanotechnology’s spread through the market has been met with mounting concerns over the potential human health effects of these miraculous materials. Because of their small size—100 nano-meters or less—nanomaterials have unique physical properties that can influence their uptake, distribution, and behavior in the body. Indeed, some nano-particles have been shown to penetrate into cells, where they can trigger inflammatory responses and oxidative stress. Canada and California recently took the unprecedented step of imposing mandated disclosure requirements on nanomaterial use and toxicity assessment. Issued 29 January 2009, Canada’s law targets domestic companies and institutions that manufacture or buy more than 1 kilogram of nanomaterial per year. According to the new regulations, these entities must now reveal how much nanomaterial they use, how they use it, and what they know about its toxicity. California’s law, issued 2 February 2009, limits its scope to carbon nanotubes, a class of nanomaterial used in electronics, optics, and biomedical applications. Under the new regulation, by February 2010 companies that manufacture, import, or export carbon nanotubes in California must disclose information about the toxicity and environmental impacts of their products. Meanwhile, experts in nanotoxicology and risk assessment have become increasingly polarized, represented on one side by the National Research Council (NRC) and on the other by the National Nanotechnology Initiative (NNI), a government-wide collaboration coordinated by the National Science and Technology Council in the Executive Office of the President. In February 2008, the Nanotechnology Environmental and Health Implications (NEHI) Working Group of the NNI released a document titled Strategy for Nanotechnology-Related Environmental, Health, and Safety Research. This document is meant to present the U.S. government’s agenda for studying nano-particle hazards, and describes 246 related projects that were ongoing in 2006, representing a combined investment for that year of $68 million. The document also purports to “address prioritized research areas . . . and to advance knowledge and support risk decision-making—both of which are essential for the responsible development of nanotechnology.” Clayton Teague directs the National Nano-technology Coordination Office, which was responsible for drafting the federal strategy. He says the strategy was developed in extensive consultation with regulatory agencies, research organizations, the business community, and nongovernmental organizations. “We believe the strategy represents needs and agreements about what the agencies plan to do,” he says. “Funding agencies are telling us that they’re using the document to formulate solicitations for future research in this area.” But on 25 February 2009, a panel assembled by the NRC issued its own report, describing what it calls serious shortcomings in the strategy document. According to the NRC panel, which was assembled at the request of the NNI, the strategy exposes weaknesses in the government’s understanding of potential nanotechnology risks today and does not adequately address how they will be assessed in the future. NRC panel member Mark Weisner, a professor of civil and environmental engineering at Duke University, claims that many of the research programs described in the NNI’s document don’t actually address environmental, health, and safety (EHS) concerns. “If you take this portfolio at face value, it overstates the true level of effort in federally financed [nano-technology-related] EHS research,” he says.