Potential use of hydroxyapatite nanoparticles (HANPs) [Ca10(PO4)6(OH)2] as slow P-release fertilizer (SRF) has recently attracted wider attention. However, commercially available HANP (with Ca/P ratio = 1.667) is the least soluble calcium phosphate and thus limits its full potential as an SRF in agronomic applications. In this research, we sought to enhance the dissolution rate of HANPs by enriching hydrogen phosphate (HPO42−) species in the phosphate (PO43−) structural sites. Seven different types of pure crystalline HANPs were synthesized at a range of Ca/P ratio from 1.46 (at pH 6.0) to 2.10 (at pH 12.0). Complementary results from FTIR and solid-state 31P MAS NMR spectroscopies showed that HPO42− species is most abundant in HANPs crystallized at pH 6.0 and gradually depleted at higher pH products. The rate of depletion of HPO42− species is proportional to the increase in carbonate incorporation into the HANP lattice, which preferentially forms B-type carbonated HANPs. The enhanced dissolution rate of HANPs due to hydrogen phosphate incorporation was tested using a flow-through macro-dialysis system that limits the partial transition of HANPs to other solid phases, which otherwise interfere with dissolution. The results show that the dissolution rate of HANPs increased with decreasing pH of synthesis and was highest in HANPs at pH 6.0. The dissolution rate differed by ten times between HANPs synthesized at pH 7.0 and 10.0. Overall, the atom-efficient synthetic route developed and the ability to tune the dissolution rate of HANPs are significant steps forward in improving the P-release efficiency of a potent SRF and is expected to contribute to efforts toward enhancing agricultural sustainability.

Plastic pollution represents an emerging environmental issue in terrestrial Antarctica, especially in the Antarctic Peninsula and Maritime Antarctica, which have been recently recognized as hot spots for plastic litter. In these regions, freshwater (FW) environments such as lakes host isolated ecosystems and species that can be severely affected by increasing environmental and anthropogenic stressors, which include plastics that are still overlooked. In this study, we investigated for the first time the impact of nanoplastics on adults of the fairy shrimp Branchinecta gaini (Order Anostraca) populating Antarctic FW ecosystems, using surface charged polystyrene nanoparticles (PS NPs) as a proxy. Short-term acute toxicity (48 h) was investigated by exposing adults to carboxyl (-COOH, 60 nm) and amino-modified (-NH2, 50 nm) PS NPs at 1 and 5 μg mL−1. Biodisposition of PS NPs and lethal and sub-lethal effects (i.e., swimming, moulting, histology, gene expression) were assessed. Behaviour of PS NPs in Antarctic FW media was monitored through 48 h of exposure showing that both PS NPs kept their nanoscale size in the Antarctic FW media. Survival of fairy shrimp adults over short-term exposure was not affected, on the other hand an increase in moulting rate and alterations in the gut epithelium were observed upon exposure to both PS NPs. Significant alterations at the behavioural (ventilation rate) and molecular (up-regulation of Hsp70mit, Hsp83, Sod, P450) levels were related to PS NP surface charge and associated with PS-NH2 exposure only. Nanoplastics could represent a threat for Antarctic FW biodiversity and the Antarctic fairy shrimp could be a valuable model for assessing their impact on such remote and pristine aquatic ecosystems.

Foliar-application of nano-particles enhanced the foliar nutrient status and crop growth and yield. It is hypothesized that being second messenger molecule, supplementation of Ca2+ via calcium nanoparticles (Ca-NPs) can trigger various signaling pathways of physiological processes which can lead to alleviate the adverse effects of drought stress on the growth of canola (Brassica napus L.). Nano-enabled foliar-application could be an ideal strategy for advancing agricultural productivity. The present study explored the role of calcium nanoparticles (Ca-NPs) in alleviating drought stress in hydroponic Brassica napus (B. napus) plants. The foliar applied Ca-NPs were spherically shaped with an average size of 86 nm. Foliar application of 100 mg L-1 Ca-NPs enhanced biomass of canola plants and considered as optimal dose. Ca-NPs at 100 mg L−1 has a greater favorable impact on mesophyll ultrastructure, PSI and PSII efficacy, gas exchange parameters, chlorophyll content, and mineral absorption. The Ca-NPs treatment increased NPQ and Y(NPQ) under drought condition, indicating a higher PSII protective response to stressed conditions with better heat dissipation as a photoprotective component of NPQ. Ca-NPs application also reduced oxidative stress damage as measured by a reduction in reactive oxygen species (ROS) generation in terms of hydrogen peroxide and malondialdehyde (H2O2 and MDA). Furthermore, Ca-NPs induced drought tolerance response corresponded to an increased in key antioxidative defense enzymes (SOD, POD, CAT, APX), as well as non-enzymatic components (protease, lipoxygenase, proline, total soluble protein contents, endogenous hormonal biosynthesis), and secondary metabolite expression in B. napus plants. Taken together, the results of this study offer new insights into the physiological and molecular mechanisms by which B. napus responds to Ca-NPs exposure.

Biochar and zeolite have been demonstrated effective to remove heavy metals in soil; however, the effect of combined application of the both materials on the fraction of Cd and soil-plant system are largely unknown. Cd fractions in soil, growth and Cd uptake of Pak Choi were measured after the combined application of biochar (0, 5, 10 and 20 g·kg−1) and nano-zeolite (0, 5, 10, 20 g·kg−1) by pot experiment. Results showed that both single and combined application reduced the exchangeable Cd in soil and improved the plant growth. However, combined application of 20 g·kg−1 biochar with 10 g·kg−1 nano-zeolite showed the strongest effect, with the residual Cd in soil increased by 214% as compared with control. 20 g·kg−1 biochar with 10 g·kg−1 nano-zeolite Mechanic studies showed that this combination enhanced the antioxidant system, with the SOD, CAT and POD activities enhanced by 56.1%, 133.3% and 235.3%, respectively. The oxidative stress was reduced correspondingly, as shown by the reduced MDA contents (by 46.7%). This combination also showed the best efficiency in regulating soil pH, organic matter and soil enzymes thus improving the plant growth. This study suggests that combined application various materials such as biochar and nano-zeolite may provide new strategies for reducing the bioavailability of Cd in soil and thus the accumulation in edible plants.

Abstract not available

This paper gathers gatekeeper views and perceptions on nano-enabled viticulture in Aotearoa New Zealand. While the science of nanotechnology is indicated to offer improvements to conventional vineyard inputs and operations, its acceptability by potential users and consumers has an impact on the governance of nano-enabled agriculture. This governance takes place not just at the state level through regulation and policy, but also through corporate, and community sectors' use of branding and narratives about nanotechnology and nano-based agrichemicals, and the (non)consumption of nano-enabled products. This paper investigates the technical and market acceptability, or governance, of nanotechnology by elucidating the attitudes of industry gatekeepers towards wines grown with nanotechnology. This necessarily informs the ‘market permissibility’ of such technologies, and illuminates sensitivities, concerns, and consumer-based barriers to adoption. We conducted 15 semi-structured, key informant interviews and a thematic data analysis. Our results suggest a high level of technical acceptability, particularly if environmental sustainability benefits are made clear. Wine producers are interested in nano-solutions to labour, pest and disease, and cost of production issues. However, key actors in the production-consumption network of New Zealand wine have concerns about nano-enabled approaches. Regulatory approval and safety assurances are expected prior to adoption in food or wine. Respondents argue that consumer acceptability is less clear, and that thought leaders like wine writers, intermediaries and ‘influencers’ will be critical in shaping public opinion. This research highlights the potential risks of nanotechnology development and adoption.

Abstract not available

MoS2 has been increasingly used in place of graphene as a flexible and multifunctional 2D material in many biomedical applications such as cancer detection and drug delivery, which makes it crucial to evaluate downstream compatibility in human immune cells. Molybdenum is a component of stainless-steel stent implants and has previously been implicated in stent hypersensitivity. In view of this, it is important to ascertain the effect of MoS2 on allergy-relevant cells. Basophils are a less commonly used immune cell type. Unlike mast cells, basophils can be easily derived from primary human blood and can act as a sentinel for allergy. However, merely testing any one type of MoS2 in basophils could result in different biological results. We thus decided to compare 2D MoS2 from the two companies BeDimensional© (BD) and Biograph Solutions (BS), manufactured with two different but commonly exploited methods (BD, deoxycholate surfactant in a high-pressure liquid exfoliation, and BS using glycine in ball-milling exfoliation) to elucidate immunological end-points common to both MoS2 and to demonstrate the need for biological verification for end-users who may require a change of supplier. We report higher histamine production in human basophils with MoS2. No effects on either surface basophil activation markers CD63 and CD203c or reactive oxygen species (ROS) production and cell viability were observed. However, different cytokine production patterns were evidenced. IL-6 and IL-1β but not TNF and GM-CSF were increased for both MoS2. BS-MoS2 increased IL-4, while BD-MoS2 decreased IL-4 and increased IL-13. Molybdate ion itself only increased IL-1β and IL-4. Deoxycholate surfactant decreased viability at 18 h and increased ROS upon basophil activation. Therefore, these results demonstrate the safety of MoS2 in human basophils in general and highlight the importance of considering manufacturer additives and variability when selecting and investigating 2D materials such as MoS2.

The terrestrial environment is one of the main recipients of plastic waste. However, limited research has been performed on soil contamination by plastics and even less assessing the effects of nanoplastics (NPls). Behind the potential toxicity caused per se, NPls are recognized vectors of other environmental harmful contaminants. Therefore, the main aim of the present study is to understand whether the toxicity of an industrial chemical (bisphenol A – BPA) and a pharmaceutical (diphenhydramine – DPH) changes in the presence of polystyrene NPls to the terrestrial invertebrate Folsomia candida. Assessed endpoints encompassed organismal (reproduction, survival and behavior) and biochemical (neurotransmission and oxidative stress) levels. BPA or DPH, 28 d single exposures (1 to 2000 mg/kg), induce no effect on organisms' survival. In terms of reproduction, the calculated EC50 (concentration that causes 50% of the effect) and determined LOEC (lowest observed effect concentration) were higher than the environmental concentrations, showing that BPA or DPH single exposure may pose no threat to the terrestrial invertebrates. Survival and reproduction effects of BPA or DPH were independent on the presence of NPls. However, for avoidance behavior (48 h exposure), the effects of the tested mixtures (BPA + NPls and DPH + NPls) were dependent on the NPls concentration (at 0.015 mg/kg – interaction: no avoidance; at 600 mg/kg – no interaction: avoidance). Glutathione S-transferase activity increased after 28 d exposure to 100 mg/kg DPH + 0.015 mg/kg NPls (synergism). The increase of lipid peroxidation levels found after the exposure to 0.015 mg/kg NPls (a predicted environmental concentration) was not detected in the mixtures (antagonism). The results showed that the effects of the binary mixtures were dependent on the assessed endpoint and the tested concentrations. The findings of the present study show the ability of NPls to alter the effects of compounds with different natures and mechanisms of toxicity towards soil organisms, showing the importance of environmental risk assessment considering mixtures of contaminants.

Graphene and its derivatives are attractive materials envisaged to enable a wealth of novel applications in many fields including energy, electronics, composite materials or health. A comprehensive understanding of the potential adverse effects of graphene-related materials (GRM) in humans is a prerequisite to the safe use of these promising materials. Here, we exploited gene expression profiling to identify transcriptional responses and toxicity pathways induced by graphene oxide (GO) and graphene nanoplatelets (GNP) in human macrophages. Primary human monocyte-derived macrophages (MDM) and a human macrophage cell line, i.e. differentiated THP-1 cells, were exposed to 5 or 20 μg/mL GO and GNP for 6 and 24 h to capture early and more persistent acute responses at realistic or slightly overdose concentrations. GO and GNP induced time-, dose- and macrophage type-specific differential expression of a substantial number of genes with some overlap between the two GRM types (up to 384 genes (9.6%) or 447 genes (20.4%) in THP-1 or MDM, respectively) but also a high number of genes exclusively deregulated from each material type. Furthermore, GRM responses on gene expression were highly different from those induced by inflammogenic material crystalline quartz (maximum of 64 (2.3%) or 318 (11.3%) common genes for MDM treated with 20 μg/mL GO and GNP, respectively). Further bioinformatics analysis revealed that GNP predominantly activated genes controlling inflammatory and apoptotic pathways whereas GO showed only limited inflammatory responses. Interestingly, both GRM affected the expression of genes related to antigen processing and presentation and in addition, GO activated pathways of neutrophil activation, degranulation and immunity in MDM. Overall, this study provides an extensive resource of potential toxicity mechanisms for future safety assessment of GRM in more advanced model systems to verify if the observed changes in gene expression in human macrophages could lead to long-term consequences on human health.

Rapid development of gold nanoparticles (GNPs) in delivering pharmaceutics and therapeutics approaches still linger the concerns of their toxic effects. Nonalcoholic steatohepatitis (NASH) is characterized by excessive lipid accumulation and overt hepatic inflammatory damage, and is the leading cause of chronic liver disease worldwide. This study aimed to assess the potential hepatic effects of GNPs on NASH phenotype and progression in mice. Mice were fed a MCD diet for 8 weeks to elicit NASH and then intravenously injected with PEG-GNPs at a single dose of 1, 5, and 25 mg/kg-bw. After 24 h and 1 week of administration, the levels of plasma ALT and AST, and the number of lipid droplets, the degree of lobular inflammation and the contents of triglycerides and cholesterols in the livers of the NASH mice significantly increased compared with the untreated NASH mice, indicating that the severity of MCD diet-induced NASH-like symptoms in mice increased after PEG-GNP administration. Moreover, the aggravated hepatic steatosis in a manner involving altered expression of the genes related to hepatic de novo lipogenesis, lipolysis, and fatty acid oxidation was observed after PEG-GNP administration. Additionally, the RNA levels of biomarkers of hepatic pro-inflammatory responses, endoplasmic reticulum stress, apoptosis, and autophagy in MCD-fed mice increased compared with the untreated NASH group. Moreover, PEG-GNP-treated NASH mice displayed an increase in MCD diet-induced hepatic fibrosis, revealed by massive deposition of collagen fiber in the liver and increased expression of fibrogenic genes. Collectively, these results suggest that hepatic GNP deposition after PEG-GNP administration increase the severity of MCD-induced NASH phenotype in mice, which is attributable to, in large part, increased steatohepatitic injury and liver fibrosis in mice.

To support a safe application of graphene-related materials (GRMs) it is necessary to understand the potential negative impacts they could have on human health, in particular on the lung - one of the most sensitive exposure routes. Machine learning (ML) approaches can help analyse the results of multiple toxicity studies to understand the structure-activity relationship and the effect of experimental conditions, thus supporting predictive nanotoxicology. In this work we collected in vitro cytotoxicity data obtained from studies using lung cells; we then fitted multiple regression models to predict this endpoint based on the material properties and experimental conditions. Moreover, the data set was used to calculate the Benchmark Dose Lower Confidence Interval (BMDL), a dose descriptor widely used in risk assessment. Regression and classification models were applied for the prediction of the BMDL value and BMDL range. The analyses show that both cytotoxicity and the BMDL range can be predicted well (Q2 = 0.77 and accuracy = 0.71, respectively). Both physico-chemical characteristics such as the lateral size, number of layers, and functionalization, and experimental conditions such as the assay and media used were important predicting features, confirming the need for thorough characterization and reporting of these parameters.

Nanoplastics (NPLs) became ubiquitous in the environment, from the air we breathe to the food we eat. One of the main concerns about the NPLs risks is their role as carrier of other environmental contaminants, potentially increasing their uptake, bioaccumulation and toxicity to the organisms. Therefore, the main aim of this study was to understand how the presence of polystyrene NPLs (∅ 44 nm) will influence the toxicity (synergism, additivity or antagonism) of the antihistamine diphenhydramine (DPH), towards zebrafish (Danio rerio) embryos, when in dual mixtures. After 96 hours (h) exposure, at the organismal level, NPLs (0.015 or 1.5 mg/L) + DPH (10 mg/L) induced embryo mortality (90%) and malformations (100%) and decreased hatching (80%) and heartbeat rates (60%). After 120 h exposure, NPLs (0.015 or 1.5 mg/L) + DPH (0.01 mg/L) decreased larvae swimming distance (30–40%). At the biochemical level, increased glutathione S-transferases (55–122%) and cholinesterase (182–343%) activities were found after 96 h exposure to NPLs (0.015 or 1.5 mg/L) + DPH (0.01 mg/L). However, catalase (CAT) activity remained similar to the control group in the mixtures, inhibiting the effects detected after the exposure to 1.5 mg/L NPLs alone (increased 230% of CAT activity). In general, the effects of dual combination – NPLs + DPH (even at concentrations as low as 10 μg/L of DPH) – were more harmful than the correspondent individual exposures, showing the synergistic interactions of the dual mixture and answering to the main question of this work. The obtained results, namely the altered toxicity patterns of NPLs + DPH compared with the individual exposures, show the importance of an environmental risk assessment considering NPLs as a co-contaminant due to the potential NPLs role as vector for other contaminants.

Nanotechnology has shown great potential to increase global food production and enhance food security. However, large-scale application of nano-enabled plant agriculture necessitates careful adjustments in design to overcome barriers associated with targeted nanomaterial delivery and their safety concerns. The research herein proposes the delivery of copper (Cu) from immobilized and non-immobilized copper oxide nanoparticles (Cu2O), an active nanomaterial with antifungal and micro-nutrient properties. A benign and biodegradable jellyfish-based hydrogel was used as a platform during Cu2O delivery to soils. The delivery kinetics and Cu dissolution from the nanocomposite were compared to those obtained with crosslinked ionic Cu in hydrogel, which was found to be a less controlled composite. In addition, changing environmental conditions from DI to soil extracts resulted in a decrease in the Cu dissolution rate (from 0.025 to 0.015 h−1) and an increase in the overall normalized Cu release (0.27 to 0.76 mg g−1). Use of hydrogels from natural sources allowed biodegradability over several months, adding nutrients (in the form of elements such as sulfur, nitrogen, and carbon) back to the environment, which ultimately minimizes nanomaterial required for a given desired nanomaterial yield and enhances the overall performance. Altogether, this work demonstrates the potential of Cu2O embedded hydrogels as a benign composite for Cu slow-release and therefore bolsters the field of nano-enabled plant agriculture and supports its safe deployment at large scales.

Macro- or micro-nutrients are essential for crop yield and nutritional quality. In this work, selenium engineering nanomaterials (Se ENMs, 0.5 mg‧kg−1) significantly increased the yield and nutritional quality of lettuce, which was better than that of selenite (Na2SeO3). Under the treatment of Se ENMs, macro-nutrients including nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were increased by 15.8%, 98.5%, 42.8%, 146.9%, and 62.5%, respectively, and micro-nutrients including manganese (Mn), iron (Fe), copper (Cu), and zinc (Zn) were also increased by 87.4%, 78.0%, 61.1%, and 56.1%, respectively. As a result, the improved nutritional status of lettuce leaves increased photosynthesis (59.2%) and yield (37.6%). Root diameters and root tips of lettuce were increased by 23.9% and 18.6%, respectively, upon exposure to Se ENMs, which may be responsible for facilitating the absorption of macro and micro nutrients from the soil. These effects were significantly better than SeO32− treated group. Metabolome results indicated that Se ENMs could improve the shikimic acid, phenylalanine, and tyrosine pathway, resulting in an enhancement of the beneficial compounds, including quercetin, rutin, and coumarin, by 2.9, 2.7, and 2.4-fold, respectively. Besides, pyruvic acid and TCA cycle were also improved by Se ENMs. These results provide new insight into the positive effect of Se ENMs on crop yield and nutritional quality, which demonstrate that the Se ENMs-enabled agriculture practices have a promising prospect as a sustainable crop strategy.

The study of multi-walled carbon nanotube (MWCNT) induced immunotoxicity is crucial for determining hazards posed to human health. MWCNT exposure most commonly occurs via the airways, where macrophages are first line responders. Here we exploit an in vitro assay, measuring dose-dependent secretion of a wide panel of cytokines, as a measure of immunotoxicity following the non-lethal, multi-dose exposure (IC5, IC10 and IC20) to 7 MWCNTs with different intrinsic properties. We find that a tangled structure, and small aspect ratio are key properties predicting MWCNT induced immunotoxicity, mediated predominantly by IL1B cytokine secretion. To assess the mechanism of action giving rise to MWCNT immunotoxicity, transcriptomics analysis was linked to cytokine secretion in a multilayer model established through correlation analysis across exposure concentrations. This reinforced the finding that tangled MWCNTs have greater immunomodulatory potency, displaying enrichment of immune system, signal transduction and pattern recognition associated pathways. Together our results further elucidate how structure, length and aspect ratio, critical intrinsic properties of MWCNTs, are tied to immunotoxicity.

Nanomaterial have shown excellent properties in the food industry. Although iron oxides are often considered safe and widely used as food additives, the toxicity of nano‑iron oxide remains unclear. Here we established a subchronic exposure mouse model by gavage, tested the biodistribution of nano‑iron oxide, and explored the mechanism of liver injury caused by it through disturbance of the gut-liver axis. Oral intake of nano‑iron oxide will likely disrupt the small intestinal epithelial barrier, induce hepatic lipid metabolism disorders through the gut–liver axis, and cause hepatic damage accompanied with hepatic iron deposition. Nano‑iron oxide mainly caused hepatic lipid metabolism disorder by perturbing glycerophospholipid metabolism and the sphingolipid metabolism pathways, with the total abundance of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) tending to decrease while that of triglyceride tended to increase, in a time- and dose-dependent manner. The imbalanced lipid homeostasis could cause damage via membrane disruption, lipid accumulation, and lipotoxicity. This data provides information about the subchronic toxicity of nano‑iron oxide, highlights the importance of gut-liver axis in the hepatotoxicity.

The presence of nanoplastics in the environment has been proven. There is now an urgent need to determine how nanoplastics behave in the environment and to assess the risks they may pose. Here, we examine nanoplastic homo- and heteroaggregation, with a focus on environmentally relevant nanoplastic particle models. We made a systematic analysis of experimental studies, and ranked the environmental relevance of 377 different solution chemistries, and 163 different nanoplastic particle models. Since polymer latex spheres are not environmentally relevant (due to their monodisperse size, spherical shape, and smooth surface), their aggregation behavior in natural conditions is not transferable to nanoplastics. A few recent studies suggest that nanoplastic particle models that more closely mimic incidentally produced nanoplastics follow different homoaggregation pathways than latex sphere particle models. However, heteroaggregation of environmentally relevant nanoplastic particle models has seldom been studied. Despite this knowledge gap, the current evidence suggests that nanoplastics may be more sensitive to heteroaggregation than previously expected. We therefore provide an updated hypothesis about the likely environmental fate of nanoplastics. Our review demonstrates that it is essential to use environmentally relevant nanoplastic particle models, such as those produced with top-down methods, to avoid biased interpretations of the fate and impact of nanoplastics. Finally, it will be necessary to determine how the heteroaggregation kinetics of nanoplastics impact their settling rate to truly understand nanoplastics' fate and effect in the environment.

Quasi-SMILES is an extension of the traditional SMILES. The classic SMILES is a way to represent the molecular structure. The quasi-SMILES is a way to describe all eclectic conditions that are able to affect the activity of a substance or a mixture. Nano-QSAR for prediction of toxicity of Nano-mixtures built up using the database on the corresponding experimental data. Models built up for five random splits of available data in training and validation sets are suggested. The Monte Carlo method of optimization is applied to calculate so-called optimal descriptors. The optimization was carried out with two criteria of predictive potential. These are the so-called index of ideality of correlation (IIC) and correlation intensity index (CII). Applying CII gives the better statistical quality of models for toxicity Nano-mixtures towards Daphnia Magna. The statistical quality of the best model follows the determination coefficients 0.987 (training set) and 0.980 (validation set).

The research on carbon-based nanomaterial (C-NM) composites has increased in the last two decades. This family of functional materials shows outstanding mechanical, thermal and electrical properties, and are being used in a variety of applications. An important challenge remains before C-NM can be fully integrated in our production industries and our lives: to assess the release of debris during production, use, and misuse of composites and the effect they may have on the environment and on human health. During their lifecycle, composites materials can be subjected to a variety of stresses which may release particles from the macroscopic range to the nanoscale. In this review, the release of debris due to abrasion, weathering and combustion as well as their toxicity is evaluated for the three most used C-NM: Carbon Black, Carbon Nanotubes and Graphene-related materials. The goal is to stimulate a Safe-By-Design approach by guiding the selection of carbon nano-fillers for specific applications based of safety and performance.