Nanosafety: a Perspective on Nano-Bio Interactions

Engineered nanomaterials offer numerous benefits to society ranging from environmental remediation to biomedical applications such as drug or vaccine delivery as well as clean and cost-effective energy production and storage, and the promise of a more sustainable way of life. However, as nanomaterials of increasing sophistication enter the market, close attention to potential adverse effects on human health and the environment is needed. Here a critical perspective on nanotoxicological research is provided; the authors argue that it is time to leverage the knowledge regarding the biological interactions of nanomaterials to achieve a more comprehensive understanding of the human health and environmental impacts of these materials. Moreover, it is posited that nanomaterials behave like biological entities and that they should be regulated as such.

Chronic toxicity of core-shell SiC/TiO2 (nano)-particles to Daphnia magna under environmentally relevant food rations in the presence of humic acid

To date, research on the toxicity and potential environmental impacts of nanomaterials has predominantly focused on relatively simple and single-component materials, whilst more complex nanomaterials are currently entering commercial stages. The current study aimed to assess the long-term and size-dependent (60 and 500 nm) toxicity of a novel core-shell nanostructure consisting of a SiC core and TiO2 shell (SiC/TiO2, 5, 25, and 50 mg L-1) to the common model organism Daphnia magna. These novel core-shell nanostructures can be categorized as advanced materials. Experiments were conducted under environmentally realistic feeding rations and in the presence of a range of concentrations of humic acid (0.5, 2, 5, and 10 mg L-1 TOC). The findings show that although effect concentrations of SiC/TiO2 were several orders of magnitude lower than the current reported environmental concentrations of more abundantly used nanomaterials, humic acid can exacerbate the toxicity of SiC/TiO2 by reducing aggregation and sedimentation rates. The EC50 values (mean ± standard error) based on nominal SiC/TiO2 concentrations for the 60 nm particles were 28.0 ± 11.5 mg L-1 (TOC 0.5 mg L-1), 21.1 ± 3.7 mg L-1 (TOC 2 mg L-1), 18.3 ± 5.4 mg L-1 (TOC 5 mg L-1), and 17.8 ± 2.4 mg L-1 (TOC 10 mg L-1). For the 500 nm particles, the EC50 values were 34.9 ± 16.5 mg L-1 (TOC 0.5 mg L-1), 24.8 ± 5.6 mg L-1 (TOC 2 mg L-1), 28.0 ± 10.0 mg L-1 (TOC 5 mg L-1), and 23.2 ± 4.1 mg L-1 (TOC 10 mg L-1). We argue that fate-driven phenomena are often neglected in effect assessments, whilst environmental factors such as the presence of humic acid may significantly influence the toxicity of nanomaterials.

Protecting the Antibacterial Coating of Urinal Catheters for Improving Safety

Catheter-associated urinary tract infections (CAUTI) are among the most common bacterial infections associated with prolonged hospitalization and increased healthcare expenditures. Despite recent advances in the prevention and treatment of these infections, there are still many challenges remaining, among them the creation of a durable catheter coating, which prevents bacterial biofilm formation. The current work reports on a method of protecting medical tubing endowed with antibiofilm properties. Silicone catheters coated sonochemically with ZnO nanoparticles (NPs) demonstrated excellent antibiofilm effects. Toward approval by the European Medicines Agency, it was realized that the ZnO coating would not withstand the regulatory requirements of avoiding dissolution for 14 days in artificial urine examination. Namely, after exposure to urine for 14 days, the coating amount was reduced by 90%. Additional coatings with either carbon or silica maintained antibiofilm activity against Staphylococcus aureus while resisting dissolution in artificial urine for 14 days (C- or SiO2-protected catheters exhibited only 29% reduction). HR-SEM images of the protected catheters indicate the presence of the ZnO coating as well as the protective layer. Antibiofilm activity of all catheters was evaluated both before and after exposure to artificial urine. It was shown that before artificial urine exposure, all coated catheters showed high antibiofilm properties compared to the uncoated control. Exposure of ZnO-coated catheters, without the protective layer, to artificial urine had a significant effect exhibited by the decrease in antibiofilm activity by almost 2 orders of magnitude, compared to unexposed catheters. Toxicity studies performed using a reconstructed human epidermis demonstrated the safety of the improved coating. Exposure of the epidermis to ZnO catheter extracts in artificial urine affects tissue viability compared with control samples, which was not observed in the case of ZnO NPs coating with SiO2 or C. We suggest that silica and carbon coatings confer some protection against zinc ions release, improving ZnO coating safety.

Novel Organoid Culture System for Improved Safety Assessment of Nanomaterials

Over the past few decades, the increased application of nanomaterials has raised questions regarding their safety and possible toxic effects. Organoids have been suggested as promising tools, offering efficient assays for nanomaterial-induced toxicity evaluation. However, organoid systems have some limitations, such as size heterogeneity and poor penetration of nanoparticles because of the extracellular matrix, which is necessary for organoid culture. Here, we developed a novel system for the improved safety assessment of nanomaterials by establishing a 3D floating organoid paradigm. In addition to overcoming the limitations of two-dimensional systems including the lack of in vitro-in vivo cross-talk, our method provides multiple benefits as compared with conventional organoid systems that rely on an extracellular matrix for culture. Organoids cultured using our method exhibited relatively uniform sizing and structural integrity and were more conducive to the internalization of nanoparticles. Our floating culture system will accelerate the research and development of safe nanomaterials.

Linking nanomaterial-induced mitochondrial dysfunction to existing adverse outcome pathways for chemicals

The adverse outcome pathway (AOP) framework plays a crucial role in the paradigm shift of tox­icity testing towards the development and use of new approach methodologies. AOPs developed for chemicals are in theory applicable to nanomaterials (NMs). However, only initial efforts have been made to integrate information on NM-induced toxicity into existing AOPs. In a previous study, we identified AOPs in the AOP-Wiki associated with the molecular initiating events (MIEs) and key events (KEs) reported for NMs in scientific literature. In a next step, we analyzed these AOPs and found that mitochondrial toxicity plays a significant role in several of them at the molecular and cellular levels. In this study, we aimed to generate hypothesis-based AOPs related to NM-induced mitochondrial toxicity. This was achieved by integrating knowledge on NM-induced mitochondrial toxicity into all existing AOPs in the AOP-Wiki, which already includes mitochondrial toxicity as a MIE/KE. Several AOPs in the AOP-Wiki related to the lung, liver, cardiovascular and nervous system, with extensively defined KEs and key event relationships (KERs), could be utilized to develop AOPs that are relevant for NMs. However, the majority of the studies included in our literature review were of poor quality, particularly in reporting NM physicochemical characteristics, and NM-relevant mitochondrial MIEs were rarely reported. This study highlights the potential role of NM-induced mitochondrial toxicity in human-relevant adverse outcomes and identifies useful AOPs in the AOP-Wiki for the development of AOPs for NMs.

Advancing chemical safety assessment through an omics-based characterization of the test system-chemical interaction

Assessing chemical safety is essential to evaluate the potential risks of chemical exposure to human health and the environment. Traditional methods relying on animal testing are being replaced by 3R (reduction, refinement, and replacement) principle-based alternatives, mainly depending on in vitro test methods and the Adverse Outcome Pathway framework. However, these approaches often focus on the properties of the compound, missing the broader chemical-biological interaction perspective. Currently, the lack of comprehensive molecular characterization of the in vitro test system results in limited real-world representation and contextualization of the toxicological effect under study. Leveraging omics data strengthens the understanding of the responses of different biological systems, emphasizing holistic chemical-biological interactions when developing in vitro methods. Here, we discuss the relevance of meticulous test system characterization on two safety assessment relevant scenarios and how omics-based, data-driven approaches can improve the future generation of alternative methods.

Microfluidic-based skin-on-chip systems for safety assessment of nanomaterials

The skin is the body's largest organ, continuously exposed to and affected by natural and anthropogenic nanomaterials (materials with external and internal dimensions in the nanoscale range). This broad spectrum of insults gives rise to irreversible health effects (from skin corrosion to cancer). Organ-on-chip systems can recapitulate skin physiology with high fidelity and potentially revolutionize the safety assessment of nanomaterials. Here, we review current advances in skin-on-chip models and their potential to elucidate biological mechanisms. Further, strategies are discussed to recapitulate skin physiology on-chip, improving control over nanomaterials exposure and transport across cells. Finally, we highlight future opportunities and challenges from design and fabrication to acceptance by regulatory bodies and industry.

Expanding adverse outcome pathways towards one health models for nanosafety

The ever-growing production of nano-enabled products has generated the need for dedicated risk assessment strategies that ensure safety for humans and the environment. Transdisciplinary approaches are needed to support the development of new technologies while respecting environmental limits, as also highlighted by the EU Green Deal Chemicals Strategy for Sustainability and its safe and sustainable by design (SSbD) framework. The One Health concept offers a holistic multiscale approach for the assessment of nanosafety. However, toxicology is not yet capable of explaining the interaction between chemicals and biological systems at the multiscale level and in the context of the One Health framework. Furthermore, there is a disconnect between chemical safety assessment, epidemiology, and other fields of biology that, if unified, would enable the adoption of the One Health model. The development of mechanistic toxicology and the generation of omics data has provided important biological knowledge of the response of individual biological systems to nanomaterials (NMs). On the other hand, epigenetic data have the potential to inform on interspecies mechanisms of adaptation. These data types, however, need to be linked to concepts that support their intuitive interpretation. Adverse Outcome Pathways (AOPs) represent an evolving framework to anchor existing knowledge to chemical risk assessment. In this perspective, we discuss the possibility of integrating multi-level toxicogenomics data, including toxicoepigenetic insights, into the AOP framework. We anticipate that this new direction of toxicogenomics can support the development of One Health models applicable to groups of chemicals and to multiple species in the tree of life.

Don't sweat the small stuff: a conversation about nanosafety

Bengt Fadeel and Phil Sayre discuss lessons learned with respect to the safety assessment of nanomaterials, and provide a perspective on current and future challenges.

Current status and future challenges of genotoxicity OECD Test Guidelines for nanomaterials: a workshop report

Genotoxicity testing for nanomaterials remains challenging as standard testing approaches require some adaptation, and further development of nano-specific OECD Test Guidelines (TGs) and Guidance Documents (GDs) are needed. However, the field of genotoxicology continues to progress and new approach methodologies (NAMs) are being developed that could provide relevant information on the range of mechanisms of genotoxic action that may be imparted by nanomaterials. There is a recognition of the need for implementation of new and/or adapted OECD TGs, new OECD GDs, and utilization of NAMs within a genotoxicity testing framework for nanomaterials. As such, the requirements to apply new experimental approaches and data for genotoxicity assessment of nanomaterials in a regulatory context is neither clear, nor used in practice. Thus, an international workshop with representatives from regulatory agencies, industry, government, and academic scientists was convened to discuss these issues. The expert discussion highlighted the current deficiencies that exist in standard testing approaches within exposure regimes, insufficient physicochemical characterization, lack of demonstration of cell or tissue uptake and internalization, and limitations in the coverage of genotoxic modes of action. Regarding the latter aspect, a consensus was reached on the importance of using NAMs to support the genotoxicity assessment of nanomaterials. Also highlighted was the need for close engagement between scientists and regulators to (i) provide clarity on the regulatory needs, (ii) improve the acceptance and use of NAM-generated data, and (iii) define how NAMs may be used as part of weight of evidence approaches for use in regulatory risk assessments.

Enrichment of nano delivery platforms for mRNA-based nanotherapeutics

Lipid-based nanoparticles (LNP) have shown significant progress in delivering mRNA for therapeutics, particularly with the success of coronavirus disease 2019 (COVID-19) vaccines. However, there are still challenges, such as organ-specific targeting, sustained protein expression, immunogenicity, and storage that need to be addressed. Therefore, there is interest in developing additional nano drug delivery systems (DDS) to complement LNP technology. Some of these include polymer, lipid-polymer hybrid, organic/inorganic hybrid nanostructure, and inorganic nanoparticle. In our opinion, LNP technology may not be suitable for every disease scenario in categories such as infection disease, cancer, pulmonary disease, autoimmune disorders and genetic rare disease (among others). This is because different diseases may require distinct administration routes, doses, and treatment durations, as well as considerations for biological barriers that may lower the efficacy and/or exert safety concern. In this perspective, we will highlight the need and potential for enhancing the diversity of nano delivery platforms for mRNA-based nanotherapeutics.

Exocytosis of Nanoparticles: A Comprehensive Review

Both biomedical applications and safety assessments of manufactured nanomaterials require a thorough understanding of the interaction between nanomaterials and cells, including how nanomaterials enter cells, transport within cells, and leave cells. However, compared to the extensively studied uptake and trafficking of nanoparticles (NPs) in cells, less attention has been paid to the exocytosis of NPs. Yet exocytosis is an indispensable process of regulating the content of NPs in cells, which in turn influences, even decides, the toxicity of NPs to cells. A comprehensive understanding of the mechanisms and influencing factors of the exocytosis of NPs is not only essential for the safety assessment of NPs but also helpful for guiding the design of safe and highly effective NP-based materials for various purposes. Herein, we review the current status and progress of studies on the exocytosis of NPs. Firstly, we introduce experimental procedures and considerations. Then, exocytosis mechanisms/pathways are summarized with a detailed introduction of the main pathways (lysosomal and endoplasmic reticulum/Golgi pathway) and the role of microtubules; the patterns of exocytosis kinetics are presented and discussed. Subsequently, the influencing factors (initial content and location of intracellular NPs, physiochemical properties of NPs, cell type, and extracellular conditions) are fully discussed. Although there are inconsistent results, some rules are obtained, like smaller and charged NPs are more easily excreted. Finally, the challenges and future directions in the field have been discussed.

How safe are nanoscale metal-organic frameworks?

Owing to the size scales that can be accessed, the nanoscale has opened doors to new physical and chemical properties, not seen in the bulk. These properties are leveraged by nanomaterials (NMs) across a plethora of applications. More recently, nanoscale metal-organic frameworks (nMOFs) have witnessed explosive growth due to the modularity of their chemical constituents, the ability to modify their composition and structure, and exceptional properties such as permanent porosity and high surface areas. These properties have prompted the investigation of these materials for applications in biological and environmental contexts. However, one aspect that is often ignored in these discussions is their safety at a nanoscale. In this mini review, we aim to initiate a discussion on the safety and toxicity of nMOFs, drawing parallels with the existing guidelines and literature on the safety of inorganic NMs. We first describe why nMOFs are of considerable interest to the scientific community followed by a discussion on routes through which they can be exposed to the environment and living organisms, particularly shedding light on their transformation mechanisms. The review also discusses the factors affecting toxicity of nMOFs, such as their size, shape, morphology, and composition. We briefly highlight potential mechanisms of toxicity and conclude with describing the need to transition towards data-intensive computational approaches such as machine learning to establish nMOFs as credible materials for their envisioned applications.

Quantitative Prediction of Inorganic Nanomaterial Cellular Toxicity via Machine Learning

Organic chemistry has seen colossal progress due to machine learning (ML). However, the translation of artificial intelligence (AI) into materials science is challenging, where biological behavior prediction becomes even more complicated. Nanotoxicity is a critical parameter that describes their interaction with the living organisms screened in every bio-related research. To prevent excessive experiments, such properties have to be pre-evaluated. Several existing ML models partially fulfill the gap by predicting whether a nanomaterial is toxic or not. Yet, this binary categorization neglects the concentration dependencies crucial for experimental scientists. Here, an ML-based approach is proposed to the quantitative prediction of inorganic nanomaterial cytotoxicity achieving the precision expressed by 10-fold cross-validation (CV) Q²  = 0.86 with the root mean squared error (RMSE) of 12.2% obtained by the correlation-based feature selection and grid search-based model hyperparameters optimization. To provide further model flexibility, quantitative atom property-based nanomaterial descriptors are introduced allowing the model to extrapolate on unseen samples. Feature importance is calculated to find an interpretable model with optimal decision-making. These findings allow experimental scientists to perform primary in silico candidate screening and minimize the number of excessive, labor-intensive experiments enabling the rapid development of nanomaterials for medicinal purposes.

Exploring the Long-Term Tissue Accumulation and Excretion of 3 nm Cerium Oxide Nanoparticles after Single Dose Administration

Nanoparticle (NP) pharmacokinetics significantly differ from traditional small molecule principles. From this emerges the need to create new tools and concepts to harness their full potential and avoid unnecessary risks. Nanoparticle pharmacokinetics strongly depend on size, shape, surface functionalisation, and aggregation state, influencing their biodistribution, accumulation, transformations, and excretion profile, and hence their efficacy and safety. Today, while NP biodistribution and nanoceria biodistribution have been studied often at short times, their long-term accumulation and excretion have rarely been studied. In this work, 3 nm nanoceria at 5.7 mg/kg of body weight was intravenously administrated in a single dose to healthy mice. Biodistribution was measured in the liver, spleen, kidney, lung, brain, lymph nodes, ovary, bone marrow, urine, and faeces at different time points (1, 9, 30, and 100 days). Biodistribution and urinary and faecal excretion were also studied in rats placed in metabolic cages at shorter times. The similarity of results of different NPs in different models is shown as the heterogeneous nanoceria distribution in organs. After the expectable accumulation in the liver and spleen, the concentration of cerium decays exponentially, accounting for about a 50% excretion of cerium from the body in 100 days. Cerium ions, coming from NP dissolution, are most likely excreted via the urinary tract, and ceria nanoparticles accumulated in the liver are most likely excreted via the hepatobiliary route. In addition, nanoceria looks safe and does not damage the target organs. No weight loss or apathy was observed during the course of the experiments.

How to formulate hypotheses and IATAs to support grouping and read-across of nanoforms

Manufacturing and functionalizing materials at the nanoscale has led to the generation of a whole array of nanoforms (NFs) of substances varying in size, morphology, and surface characteristics. Due to financial, time, and ethical considerations, testing every unique NF for adverse effects is virtually impossible. Use of hypothesis-driven grouping and read-across approaches, as supported by the GRACIOUS Framework, represents a promising alternative to case-by-case testing that will make the risk assessment process more efficient. Through application of appropriate grouping hypotheses, the Framework facilitates the assessment of similarity between NFs, thereby supporting grouping and read-across of information, minimizing the need for new testing, and aligning with the 3R principles of replacement, reduction, and refinement of animals in toxicology studies. For each grouping hypothesis an integrated approach to testing and assessment (IATA) guides the user in data gathering and acquisition to test the hypothesis, following a structured format to facilitate efficient decision-making. Here we present the template used to generate the GRACIOUS grouping hypotheses encompassing information relevant to “Lifecycle, environmental release, and human exposure”, “What they are: physicochemical characteristics”, “Where they go: environmental fate, uptake, and toxicokinetics”, and “What they do: human and environmental toxicity”. A summary of the template-derived hypotheses focusing on human health is provided, along with an overview of the IATAs generated by the GRACIOUS project. We discuss the application and flexibility of the template, providing the opportunity to expand the application of grouping and read-across in a logical, evidence-based manner to a wider range of NFs and substances.

Macrophages Release Extracellular Vesicles of Different Properties and Composition Following Exposure to Nanoparticles

Extracellular vesicles are membrane-bound carriers with complex cargoes, which play a major role in intercellular communication, for instance, in the context of the immune response. Macrophages are known to release extracellular vesicles in response to different stimuli, and changes in their size, number, and composition may provide important insights into the responses induced. Macrophages are also known to be highly efficient in clearing nanoparticles, when in contact with them, and in triggering the immune system. However, little is known about how the nature and composition of the vesicles released by these cells may vary upon nanoparticle exposure. In order to study this, in this work, alveolar-like macrophages were exposed to a panel of nanoparticles with varying surface and composition, including amino-modified and carboxylated polystyrene and plain silica. We previously showed that these nanoparticles induced very different responses in these cells. Here, experimental conditions were carefully tuned in order to separate the extracellular vesicles released by the macrophages several hours after exposure to sub-toxic concentrations of the same nanoparticles. After separation, different methods, including high-sensitivity flow cytometry, TEM imaging, Western blotting, and nanoparticle tracking analysis, were combined in order to characterize the extracellular vesicles. Finally, proteomics was used to determine their composition and how it varied upon exposure to the different nanoparticles. Our results show that depending on the nanoparticles' properties. The macrophages produced extracellular vesicles of varying number, size, and protein composition. This indicates that macrophages release specific signals in response to nanoparticles and overall suggests that extracellular vesicles can reflect subtle responses to nanoparticles and nanoparticle impact on intercellular communication.

In Vivo Evaluation of DMSA-Coated Magnetic Nanoparticle Toxicity and Biodistribution in Rats: A Long-Term Follow-Up

This work presents a long-term follow-up (300 days) of rats after a single intravenous injection of DMSA-coated magnetite nanoparticles (DMSA-MNP). The animals were systematically evaluated by hematological, biochemical, and ultrasound examinations, monitoring the same animal over time. In addition, oxidative stress evaluation, DMSA-MNP biodistribution, computerized tomography for ex vivo organs, and histopathology analysis were performed at the end of the experiment period. Overall, DMSA-MNP administration did not cause serious damage to the rats' health over the course of 300 days post-administration. All animals presented hematological parameters within the normal limits, and no alterations on serum creatinine, urea, ALT, and AST were related to DMSA-MNP administration. Liver and spleen showed no important alterations in any of the examinations. The kidneys of treated animals displayed intermittent pelvis dilation at ultrasound analysis, but without damage to the organ parenchyma after 300 days. The lungs of treated animals presented a light interalveolar septal thickening, but the animals did not present any clinical respiratory symptom. Nanoparticles were not detected in the vital organs of treated animals 300 days after administration. This work represents the first assessment of the long-term effects of DMSA-MNP and goes a step further on the safety of its use for biomedical applications.

Adverse Outcome Pathways Associated with the Ingestion of Titanium Dioxide Nanoparticles-A Systematic Review

Titanium dioxide nanoparticles (TiO₂-NPs) are widely used, and humans are exposed through food (E171), cosmetics (e.g., toothpaste), and pharmaceuticals. The oral and gastrointestinal (GIT) tract are the first contact sites, but it may be systemically distributed. However, a robust adverse outcome pathway (AOP) has not been developed upon GIT exposure to TiO₂-NPs. The aim of this review was to provide an integrative analysis of the published data on cellular and molecular mechanisms triggered after the ingestion of TiO₂-NPs, proposing plausible AOPs that may drive policy decisions. A systematic review according to Prisma Methodology was performed in three databases of peer-reviewed literature: Pubmed, Scopus, and Web of Science. A total of 787 records were identified, screened in title/abstract, being 185 used for data extraction. The main endpoints identified were oxidative stress, cytotoxicity/apoptosis/cell death, inflammation, cellular and systemic uptake, genotoxicity, and carcinogenicity. From the results, AOPs were proposed where colorectal cancer, liver injury, reproductive toxicity, cardiac and kidney damage, as well as hematological effects stand out as possible adverse outcomes. The recent transgenerational studies also point to concerns with regard to population effects. Overall, the findings further support a limitation of the use of TiO₂-NPs in food, announced by the European Food Safety Authority (EFSA).

Recent Advances in Targeted Nanotherapies for Ischemic Stroke

Ischemic stroke (IS) is a severe neurological disease caused by the narrowing or occlusion of cerebral blood vessels and is known for high morbidity, disability, and mortality rates. Clinically available treatments of stroke include the surgical removal of the thrombus and thrombolysis with tissue fibrinogen activator. Pharmaceuticals targeting IS are uncommon, and the development of new therapies is hindered by the low bioavailability and stability of many drugs. Nanomedicine provides new opportunities for the development of novel neuroprotective and thrombolytic strategies for the diagnosis and treatment of IS. Numerous nanotherapeutics with different physicochemical properties are currently being developed to facilitate drug delivery by accumulation and controlled release and to improve their restorative properties. In this review, we discuss recent developments in IS therapy, including assisted drug delivery and targeting, neuroprotection through regulation of the neuron environment, and sources of endogenous biomimetic specific targeting. In addition, we discuss the role and neurotoxic effects of inorganic metal nanoparticles in IS therapy. This study provides a theoretical basis for the utilization of nano-IS therapies that may contribute to the development of new strategies for a range of embolic diseases.

Occupational Safety Analysis for COVID-Instigated Repurposed Manufacturing Lines: Use of Nanomaterials in Injection Moulding

The COVID-19 pandemic instigated massive production of critical medical supplies and personal protective equipment. Injection moulding (IM) is considered the most prominent thermoplastic part manufacturing technique, offering the use of a large variety of feedstocks and rapid production capacity. Within the context of the European Commission-funded imPURE project, the benefits of IM have been exploited in repurposed IM lines to accommodate the use of nanocomposites and introduce the unique properties of nanomaterials. However, these amendments in the manufacturing lines highlighted the need for targeted and thorough occupational risk analysis due to the potential exposure of workers to airborne nanomaterials and fumes, as well as the introduction of additional occupational hazards. In this work, a safety-oriented failure mode and effects analysis (FMEA) was implemented to evaluate the main hazards in repurposed IM lines using acrylonitrile butadiene styrene (ABS) matrix and silver nanoparticles (AgNPs) as additives. Twenty-eight failure modes were identified, with the upper quartile including the seven failure modes presenting the highest risk priority numbers (RPN), signifying a need for immediate control action. Additionally, a nanosafety control-banding tool allowed hazard classification and the identification of control actions required for mitigation of occupation risks due to the released airborne silver nanoparticles.

The Road to Achieving the European Commission's Chemicals Strategy for Nanomaterial Sustainability-A PATROLS Perspective on New Approach Methodologies

The European Green Deal outlines ambitions to build a more sustainable, climate neutral, and circular economy by 2050. To achieve this, the European Commission has published the Chemicals Strategy for Sustainability: Towards a Toxic-Free Environment, which provides targets for innovation to better protect human and environmental health, including challenges posed by hazardous chemicals and animal testing. The European project PATROLS (Physiologically Anchored Tools for Realistic nanOmateriaL hazard aSsessment) has addressed multiple aspects of the Chemicals Strategy for Sustainability by establishing a battery of new approach methodologies, including physiologically anchored human and environmental hazard assessment tools to evaluate the safety of engineered nanomaterials. PATROLS has delivered and improved innovative tools to support regulatory decision-making processes. These tools also support the need for reducing regulated vertebrate animal testing; when used at an early stage of the innovation pipeline, the PATROLS tools facilitate the safe and sustainable development of new nano-enabled products before they reach the market.

Understanding Nanomaterial-Liver Interactions to Facilitate the Development of Safer Nanoapplications

Nanomaterials (NMs) are widely used in commercial and medical products, such as cosmetics, vaccines, and drug carriers. Exposure to NMs via various routes such as dermal, inhalation, and ingestion has been shown to gain access to the systemic circulation, resulting in the accumulation of NMs in the liver. The unique organ structures and blood flow features facilitate the liver sequestration of NMs, which may cause adverse effects in the liver. Currently, most in vivo studies are focused on NMs accumulation at the organ level and evaluation of the gross changes in liver structure and functions, however, cell-type-specific uptake and responses, as well as the molecular mechanisms at cellular levels leading to effects at organ levels are lagging. Herein, the authors systematically review diverse interactions of NMs with the liver, specifically on major liver cell types including Kupffer cells (KCs), liver sinusoidal endothelial cells (LSECs), hepatic stellate cells (HSCs), and hepatocytes as well as the detailed molecular mechanisms involved. In addition, the knowledge gained on nano-liver interactions that can facilitate the development of safer nanoproducts and nanomedicine is also reviewed.

A Transcriptomic Analysis of T98G Human Glioblastoma Cells after Exposure to Cadmium-Selenium Quantum Dots Mainly Reveals Alterations in Neuroinflammation Processes and Hypothalamus Regulation

Quantum dots are nanoparticles with very promising biomedical applications. However, before these applications can be authorized, a complete toxicological assessment of quantum dots toxicity is needed. This work studied the effects of cadmium-selenium quantum dots on the transcriptome of T98G human glioblastoma cells. It was found that 72-h exposure to 40 µg/mL (a dose that reduces cell viability by less than 10%) alters the transcriptome of these cells in biological processes and molecular pathways, which address mainly neuroinflammation and hormonal control of hypothalamus via the gonadotropin-releasing hormone receptor. The biological significance of neuroinflammation alterations is still to be determined because, unlike studies performed with other nanomaterials, the expression of the genes encoding pro-inflammatory interleukins is down-regulated rather than up-regulated. The hormonal control alterations of the hypothalamus pose a new concern about a potential adverse effect of quantum dots on fertility. In any case, more studies are needed to clarify the biological relevance of these findings, and especially to assess the real risk of toxicity derived from quantum dots exposure appearing in physiologically relevant scenarios.

Nanosafety: a knowledge, attitude and practice (KAP) study among Iranian researchers working in nanotechnology laboratories

Objectives. There is a set of evidence about the adverse effects of engineered nanomaterials (ENMs) on humans and the environment. People working with nanomaterials (NMs) (in nanotechnology laboratories and workplaces) are often exposed to these materials. Following nanosafety principals can reduce exposure to ENMs. This study aimed to investigate the knowledge, attitude and practice (KAP) of Iranian researchers toward nanosafety. Methods. This descriptive cross-sectional study was conducted via a questionnaire designed using the results of a literature review and validated by a panel of experts. After completion of questionnaires by Iranian researchers, data were analyzed using SPSS version 20.0. Results. Investigation into the knowledge of study participants showed that 61.38% of them answered the questions correctly. Although 74.34% of the study participants had a proper attitude to nanosafety, only 27.3% of them considered ENMs to be harmful to humans and the environment. Examination of researchers' performance in laboratories showed that 24.25% of them 'always' have good performance. Conclusions. It seems that increasing awareness by teaching the principles of working safely with NMs can help to create a positive attitude toward the principles of nanosafety. Positive attitude can finally lead to the optimal performance of researchers in laboratories involved with NMs.

Methods, models, mechanisms and metadata: Introducing the Nanotoxicology collection at F1000Research

Nanotoxicology is a relatively new field of research concerning the study and application of nanomaterials to evaluate the potential for harmful effects in parallel with the development of applications. Nanotoxicology as a field spans materials synthesis and characterisation, assessment of fate and behaviour, exposure science, toxicology / ecotoxicology, molecular biology and toxicogenomics, epidemiology, safe and sustainable by design approaches, and chemoinformatics and nanoinformatics, thus requiring scientists to work collaboratively, often outside their core expertise area. This interdisciplinarity can lead to challenges in terms of interpretation and reporting, and calls for a platform for sharing of best-practice in nanotoxicology research. The F1000Research Nanotoxicology collection, introduced via this editorial, will provide a place to share accumulated best practice, via original research reports including no-effects studies, protocols and methods papers, software reports and living systematic reviews, which can be updated as new knowledge emerges or as the domain of applicability of the method, model or software is expanded. This editorial introduces the Nanotoxicology Collection in F1000Research. The aim of the collection is to provide an open access platform for nanotoxicology researchers, to support an improved culture of data sharing and documentation of evolving protocols, biological and computational models, software tools and datasets, that can be applied and built upon to develop predictive models and move towards in silico nanotoxicology and nanoinformatics. Submissions will be assessed for fit to the collection and subjected to the F1000Research open peer review process.

Identifying diverse metal oxide nanomaterials with lethal effects on embryonic zebrafish using machine learning

Manufacturers of nanomaterial-enabled products need models of endpoints that are relevant to human safety to support the "safe by design" paradigm and avoid late-stage attrition. Increasingly, embryonic zebrafish (Danio Rerio) are recognised as a key human safety relevant in vivo test system. Hence, machine learning models were developed for identifying metal oxide nanomaterials causing lethality to embryonic zebrafish up to 24 hours post-fertilisation, or excess lethality in the period of 24-120 hours post-fertilisation, at concentrations of 250 ppm or less. Models were developed using data from the Nanomaterial Biological-Interactions Knowledgebase for a dataset of 44 diverse, coated and uncoated metal or, in one case, metalloid oxide nanomaterials. Different modelling approaches were evaluated using nested cross-validation on this dataset. Models were initially developed for both lethality endpoints using multiple descriptors representing the composition of the core, shell and surface functional groups, as well as particle characteristics. However, interestingly, the 24 hours post-fertilisation data were found to be harder to predict, which could reflect different exposure routes. Hence, subsequent analysis focused on the prediction of excess lethality at 120 hours-post fertilisation. The use of two data augmentation approaches, applied for the first time in nano-QSAR research, was explored, yet both failed to boost predictive performance. Interestingly, it was found that comparable results to those originally obtained using multiple descriptors could be obtained using a model based upon a single, simple descriptor: the Pauling electronegativity of the metal atom. Since it is widely recognised that a variety of intrinsic and extrinsic nanomaterial characteristics contribute to their toxicological effects, this is a surprising finding. This may partly reflect the need to investigate more sophisticated descriptors in future studies. Future studies are also required to examine how robust these modelling results are on truly external data, which were not used to select the single descriptor model. This will require further laboratory work to generate comparable data to those studied herein.

NanoSafe III: A User Friendly Safety Management System for Nanomaterials in Laboratories and Small Facilities

Research in nanoscience continues to bring forward a steady stream of new nanomaterials and processes that are being developed and marketed. While scientific committees and expert groups deal with the harmonization of terminology and legal challenges, risk assessors in research labs continue to have to deal with the gap between regulations and rapidly developing information. The risk assessment of nanomaterial processes is currently slow and tedious because it is performed on a material-by-material basis. Safety data sheets are rarely available for (new) nanomaterials, and even when they are, they often lack nano-specific information. Exposure estimations or measurements are difficult to perform and require sophisticated and expensive equipment and personal expertise. The use of banding-based risk assessment tools for laboratory environments is an efficient way to evaluate the occupational risks associated with nanomaterials. Herein, we present an updated version of our risk assessment tool for working with nanomaterials based on a three-step control banding approach and the precautionary principle. The first step is to determine the hazard band of the nanomaterial. A decision tree allows the assignment of the material to one of three bands based on known or expected effects on human health. In the second step, the work exposure is evaluated and the processes are classified into three "nano" levels for each specific hazard band. The work exposure is estimated using a laboratory exposure model. The result of this calculation in combination with recommended occupational exposure limits (rOEL) for nanomaterials and an additional safety factor gives the final "nano" level. Finally, we update the technical, organizational, and personal protective measures to allow nanomaterial processes to be established in research environments.

Mechanisms of Silver Nanoparticle Uptake by Embryonic Zebrafish Cells

Evaluation of the uptake pathways in cells during exposure to nanoparticles (NPs) is key for risk assessment and the development of safer nanomaterials, as the internalisation and fate of NPs is linked to their toxicity and mode of action. Here, we determined the uptake mechanisms activated during the internalisation of 10, 30, and 100 nm AgNPs by embryonic zebrafish cells (ZF4). The uptake results demonstrated an NP size- and time-dependent uptake, showing the highest total silver uptake for the smallest AgNP (10 nm) at the lowest exposure concentration (2.5 μg/mL) after 2 h, while after 24 h, the highest exposure concentration (10 μg/mL) of the 10 nm AgNPs revealed the highest cellular load at 8 pg/cell. Inhibition of the caveolae, clathrin, and macropinocytosis endocytic pathways by pharmaceutical inhibitors (genistein, chlorpromazine, and wortmannin respectively) revealed that uptake was mainly via macropinocytosis for the 10 nm AgNPs and via the caveolae-mediated pathway for the 30 and 100 nm AgNPs. The induction of autophagy was also strongly related to the NP size, showing the highest percentage of induction for the 10 nm (around 3%) compared to naive cells, suggesting that autophagy can be activated along with endocytosis to deal with exposure to NPs. TEM imaging revealed the distribution of NPs across the cytoplasm inside intracellular vesicles. An increase in Early Endosome formation (EE) was observed for the 30 and 100 nm sizes, whereas the 10 nm AgNPs disrupted the activity of EE. The data supports the establishment of adverse outcome pathways by increasing knowledge on the link between a molecular initiating event such as receptor-mediated endocytosis and an adverse outcome, as well as supporting the reduction of animal testing by using alternative testing models, such as fish cell lines.

nanotoxicology: adequate animal models for testing in vivo toxicity of nanoparticles

Nanotoxicological studies using existing models of normal cells and animals often encounter a paradox: retention of nanoparticles in intracellular compartments for a long time is not accompanied by any significant toxicological effects. Can we expect that the revealed changes will be not harmful after translation to practice, outside of a sterile laboratory and ideally healthy organisms? Age-associated and pathological processes can affect target organs, metabolism, and detoxification in the mononuclear phagocyte system organs and change biodistribution routes, thus making the use of nanomaterial not safe. The potential solution to this issue can be testing the toxic properties of nanoparticles in animal models with chronic diseases. However, current studies of nanotoxicity in animal models with a brain, cardiovascular system, liver, digestive tract, reproductive system, and skin diseases are unsystematic. Even though these studies demonstrate the emergence of new toxic effects that are not present in healthy animals. In this regard, we set the goal of this review as the formulation of the requirements for an animal model capable of assessing the potential toxicity of nanoparticles based on the nanosafety approach.

The Action-Networks of Nanosilver: Bridging the Gap between Material and Biology

The emergence of nanosilver (silver in nanoscale shapes and their assemblies) benefits the landscape of modern healthcare; however, this brings about concerns over its safety issues associated with an ultrasmall size and high mobility. By reviewing previous reporting details about the synthesis and characterization of nanosilver and its biological responses, a gap between materials synthesis and their biomedical uses is characterized by the insufficient understanding of the interacting and interplaying nanoscale actions of silver. To improve reporting quality and advance clinical translations, it is suggested that researchers have a comprehensive recognition of the "Indications for use" before designing innovative nanosilver-based materials and an "Action-network" concept addressing the acting range and strength of those nanoscale actions is implemented. Although this discussion is specific to nanosilver, the idea of "Indications for use" centered design and synthesis is generally applicable to other biomedical nanomaterials.

Nanotherapeutics and nanotheragnostics for cancers: properties, pharmacokinetics, biopharmaceutics, and biosafety

With the worldwide increasing rate of chronic diseases, such as cancer, the development of novel techniques to improve the efficacy of therapeutic agents is highly demanded. Nanoparticles are especially well suited to encapsulate drugs and other therapeutic agents, bringing additional advantages, such as less frequent dosage requirements, reduced side effects due to specific targeting, and therefore increased patient compliance. However, with the increasing use of nanoparticles and their recent launch on the pharmaceutical market it is important to achieve high quality control of these advanced systems. In this review, we discuss the properties of different nanoparticles, the pharmacokinetics, the biosafety issues of concern, and conclude with novel nanotherapeutics and nanotheragnostics for cancer drug delivery.

Safety Assessment of Polypyrrole Nanoparticles and Spray-Coated Textiles

Polypyrrole (PPy) nanoparticles (NPs) are used for the coating of materials, such as textiles, with biomedical applications, including wound care and tissue engineering, but they are also promising antibacterial agents. In this work, PPy NPs were used for the spray-coating of textiles with antimicrobial properties. The functional properties of the materials were verified, and their safety was evaluated. Two main exposure scenarios for humans were identified: inhalation of PPy NPs during spray (manufacturing) and direct skin contact with NPs-coated fabrics (use). Thus, the toxicity properties of PPy NPs and PPy-coated textiles were assessed by using in vitro models representative of the lung and the skin. The results from the materials' characterization showed the stability of both the PPy NP suspension and the textile coating, even after washing cycles and extraction in artificial sweat. Data from an in vitro model of the air-blood barrier showed the low toxicity of these NPs, with no alteration of cell viability and functionality observed. The skin toxicity of PPy NPs and the coated textiles was assessed on a reconstructed human epidermis model following OECD 431 and 439 guidelines. PPy NPs proved to be non-corrosive at the tested conditions, as well as non-irritant after extraction in artificial sweat at two different pH conditions. The obtained data suggest that PPy NPs are safe NMs in applications for textile coating.

Recent Advances in Immunosafety and Nanoinformatics of Two-Dimensional Materials Applied to Nano-imaging

Two-dimensional (2D) materials have emerged as an important class of nanomaterials for technological innovation due to their remarkable physicochemical properties, including sheet-like morphology and minimal thickness, high surface area, tuneable chemical composition, and surface functionalization. These materials are being proposed for new applications in energy, health, and the environment; these are all strategic society sectors toward sustainable development. Specifically, 2D materials for nano-imaging have shown exciting opportunities in in vitro and in vivo models, providing novel molecular imaging techniques such as computed tomography, magnetic resonance imaging, fluorescence and luminescence optical imaging and others. Therefore, given the growing interest in 2D materials, it is mandatory to evaluate their impact on the immune system in a broader sense, because it is responsible for detecting and eliminating foreign agents in living organisms. This mini-review presents an overview on the frontier of research involving 2D materials applications, nano-imaging and their immunosafety aspects. Finally, we highlight the importance of nanoinformatics approaches and computational modeling for a deeper understanding of the links between nanomaterial physicochemical properties and biological responses (immunotoxicity/biocompatibility) towards enabling immunosafety-by-design 2D materials.

Influence of Physicochemical Characteristics and Stability of Gold and Silver Nanoparticles on Biological Effects and Translocation across an Intestinal Barrier-A Case Study from In Vitro to In Silico

A better understanding of their interaction with cell-based tissue is a fundamental prerequisite towards the safe production and application of engineered nanomaterials. Quantitative experimental data on the correlation between physicochemical characteristics and the interaction and transport of engineered nanomaterials across biological barriers, in particular, is still scarce, thus hampering the development of effective predictive non-testing strategies. Against this background, the presented study investigated the translocation of gold and silver nanoparticles across the gastrointestinal barrier along with related biological effects using an in vitro 3D-triple co-culture cell model. Standardized in vitro assays and quantitative polymerase chain reaction showed no significant influence of the applied nanoparticles on both cell viability and generation of reactive oxygen species. Transmission electron microscopy indicated an intact cell barrier during the translocation study. Single particle ICP-MS revealed a time-dependent increase of translocated nanoparticles independent of their size, shape, surface charge, and stability in cell culture medium. This quantitative data provided the experimental basis for the successful mathematical description of the nanoparticle transport kinetics using a non-linear mixed effects modeling approach. The results of this study may serve as a basis for the development of predictive tools for improved risk assessment of engineered nanomaterials in the future.

A strategy towards the generation of testable adverse outcome pathways for nanomaterials

Manufactured nanomaterials (NMs) are increasingly used in a wide range of industrial applications leading to a constant increase in the market size of nano-enabled products.  The increased production and use of NMs are constantly raising concerns among different stakeholder groups with regard to their effects on human and environmental health. Currently, nanosafety hazard assessment is still widely performed using in vivo (animal) models, however the development of robust and regulatory relevant strategies is required to prioritize and/or reduce animal testing. Adverse outcome pathways (AOPs) are a structured representation of biological events that start from a molecular initiating event (MIE) leading to an adverse outcome (AO) through a series of key events (KEs). The AOP framework offers great advancement to risk assessment and regulatory safety assessments. While AOPs for chemicals have been more frequently reported, AOPs collection for NMs is narrow. By using existing AOPs, we aimed to generate simple and testable strategies to predict if a given NM has the potential to induce a MIE leading to an AO through a series of KEs. Firstly, we identified potential MIEs or initial KEs reported for NMs in the literature. Then, we searched the identified MIE or initial KEs as keywords in the AOP-Wiki to find associated AOPs.  Finally, using two case studies, we demonstrated here how in vitro strategies can be used for testing the identified MIE/KEs.

Co-exposure to boscalid and TiO2 (E171) or SiO2 (E551) downregulates cell junction gene expression in small intestinal epithelium cellular model and increases pesticide translocation

A recent published study showed that TiO₂ (E171) and SiO₂ (E551), two widely used nano-enabled food additives, increased the translocation of the commonly used pesticide boscalid by 20% and 30% respectively. Such increased absorption of pesticides due to the presence of engineered nanomaterials (ENMs) in food raises health concerns for these food additives. In this companion study, mRNA expression of genes related to cell junctions in a small intestinal epithelial cellular model after exposure to simulated digestas of fasting food model (phosphate buffer) containing boscalid (150 ppm) with or without either TiO₂ or SiO₂ (1% w/w) were analyzed. Specific changes in cell barrier function underlying or contributing to the increased translocation of boscalid observed in the previous study were assessed. Results showed that exposure to boscalid alone has no significant effect on cell junction genes, however, co-exposure to boscalid and TiO₂ significantly regulated expression of cell-matrix junction focal adhesion-related genes, e.g., downregulating Cav1 (- 1.39-fold, p<0.05), upregulating Cav3 (+ 3.30-fold, p<0.01) and Itga4 (+ 3.30-fold, p<0.05). Similarly, co-exposure to boscalid and SiO₂ significantly downregulated multiple cell-cell junction genes, including tight junction genes (Cldn1, Cldn11, Cldn16, Cldn18, and Jam3), adherens junction genes (Notch1, Notch3, Pvrl1) and gap junction genes (Gja3 and Gjb2), as well as cell-matrix junction focal adhesion genes (Itga4, Itga6, Itga7). Together, these findings suggest that co-ingestion of boscalid with TiO₂ (E171) or SiO₂ (E551) could cause weakening of cell junctions and intercellular adhesion, which could result in dysregulation of paracellular transport, and presumably contributed to the previously observed increased translocation of boscalid at the presence of these ENMs. This novel finding raises health safety concerns for such popular food additives.

Therapeutic nanostructures and nanotoxicity

Nanotechnology, with its continuous advancement, leads to the development of nanoscale-level therapeutics to mitigate many complex diseases. This results in the emergence of numerous novel nanomaterials and its composite products into the market such as liposome, polymeric nanoparticles, dendrimers, and nanostructured lipid carrier. However, their application is always determined by a high benefit to risk ratio. Very few research have been done on the toxicity assessment of nanoparticles in the biological system; therefore, the limited knowledge regarding the toxicity profile of nanotherapeutics is available leading to the ignorance of its side effects. Nanoparticles can distribute in the whole body through translocating in the bloodstream by crossing membrane barriers efficiently and shows effect in organs and tissues at cellular and molecular levels. The interaction of nanoparticle with cell may consequences into nanotoxicity. The narrow size distribution, large surface area to mass ratio and surface properties of nanoparticle are significantly associated with nanotoxicity. Nanoparticles can enter into the tissue and cell by invading the membranes and cause cellular injury as well as toxicity. Therefore, the exploration of mechanisms of nanotoxicity has prime importance now a day. The toxicity assessment should be an integral part of the development of nanotherapeutics using various toxicity evaluation models. This review has focused on the exploration of different nanostructures for therapeutic delivery system along with its physicochemical characteristics responsible for adverse effects on human biology, various toxicity evaluation models, and environmental and regulatory hurdles.

RNA m6A Modification Alteration by Black Phosphorus Quantum Dots Regulates Cell Ferroptosis: Implications for Nanotoxicological Assessment

Nanosafety is a major concern for nanotechnology development. Evaluation of the transcriptome and the DNA methylome is proposed for nanosafety assessments. RNA m6A modification plays a crucial role in development, disease, and cell fate determination through regulating RNA stability and decay. Here, since black phosphorus quantum dots (BPQDs), among many other types of QDs, increase the global m6A level and decrease the demethylase ALKBH5 level in lung cells, the epitranscriptome is taken into consideration for the first time to evaluate nanosafety. Both the transcriptome and m6A epitranscriptome analyses show that BPQDs alter many biological processes, such as the response to selenium ions and the lipoxygenase pathway, indicating possible ferroptosis activation. The results further show that BPQDs cause lipid peroxidation, mitochondrial dysfunction, and iron overload. Recognition of these modified mRNAs by YTHDF2 leads to mRNAs' decay and eventually ferroptosis. This study shows that RNA m6A modification not only is a more sophisticated indicator for nanosafety assessment but also provides novel insight into the role of RNA m6A in regulating BPQD-induced ferroptosis, which may be broadly applicable to understanding the functions of RNA m6A under stress.

Investigating the relationship between occupational exposure to nanomaterials and symptoms of nanotechnology companies' employees

PURPOSE

The increasing use of nanomaterials in academic and industrial environments has raised concerns about the potential effects of these materials on human and the environment. Researches have shown that occupational exposure to nanomaterials can affect employees' health. Many companies are active in the field of nanotechnology in Iran. Therefore, this study was designed and conducted to investigate the relationship between the symptoms of these companies' employees and exposure to nanomaterials.

METHODS

The study was conducted among employees of 52 nanotechnology companies in Tehran. For this study, the employees of these companies were categorized in two groups: "exposed" and "non-exposed" to nanomaterials. Data collection tools included the NanoTool method form and a nonspecific symptom questionnaire designed and validated by a team of 19 experts in various fields. Finally, data were analyzed using SPSS.22 software.

RESULTS

The results showed that the frequency of cutaneous (such as roughness, itching and redness), respiratory (such as cough, sneezing, and burning throat) and ocular (such as burning, itching and redness) symptoms were higher among the exposed workers to nanomaterials. Examination of the correlation between these symptoms in the two studied groups showed that symptoms with high frequency have a significant relationship with exposure to nanomaterials.

CONCLUSIONS

Given the high prevalence of some symptoms among the employees of the studied companies and their association with exposure to nanomaterials, it seems necessary to take control measures to reduce the exposure of employees to nanomaterials and consequently reduce the Investigated symptoms.

Management of Occupational Risk Prevention of Nanomaterials Manufactured in Construction Sites in the EU

Currently, nanotechnology plays a key role for technological innovation, including the construction sector. An exponential increase is expected in its application, although this has been hampered by the current degree of uncertainty regarding the potential effects of nanomaterials on both human health and the environment. The accidents, illnesses, and disease related to the use of nanoproducts in the construction sector are difficult to identify. For this purpose, this work analyzes in depth the products included in recognized inventories and the safety data sheets of these construction products. Based on this analysis, a review of the recommendations on the use of manufactured nanomaterials at construction sites is performed. Finally, a protocol is proposed with the aim of it serving as a tool for technicians in decision-making management at construction sites related to the use of manufactured nanomaterials. This proposed protocol should be an adaptive and flexible tool while the manufactured nanomaterials-based work continues to be considered as an "emerging risk," despite the expectation that the protocol will be useful for the development of new laws and recommendations for occupational risk prevention management.

Metadata Stewardship in Nanosafety Research: Community-Driven Organisation of Metadata Schemas to Support FAIR Nanoscience Data

The emergence of nanoinformatics as a key component of nanotechnology and nanosafety assessment for the prediction of engineered nanomaterials (NMs) properties, interactions, and hazards, and for grouping and read-across to reduce reliance on animal testing, has put the spotlight firmly on the need for access to high-quality, curated datasets. To date, the focus has been around what constitutes data quality and completeness, on the development of minimum reporting standards, and on the FAIR (findable, accessible, interoperable, and reusable) data principles. However, moving from the theoretical realm to practical implementation requires human intervention, which will be facilitated by the definition of clear roles and responsibilities across the complete data lifecycle and a deeper appreciation of what metadata is, and how to capture and index it. Here, we demonstrate, using specific worked case studies, how to organise the nano-community efforts to define metadata schemas, by organising the data management cycle as a joint effort of all players (data creators, analysts, curators, managers, and customers) supervised by the newly defined role of data shepherd. We propose that once researchers understand their tasks and responsibilities, they will naturally apply the available tools. Two case studies are presented (modelling of particle agglomeration for dose metrics, and consensus for NM dissolution), along with a survey of the currently implemented metadata schema in existing nanosafety databases. We conclude by offering recommendations on the steps forward and the needed workflows for metadata capture to ensure FAIR nanosafety data.

No small matter: a perspective on nanotechnology-enabled solutions to fight COVID-19

There is an urgent need for safe and effective approaches to combat COVID-19. Here, we asked whether lessons learned from nanotoxicology and nanomedicine could shed light on the current pandemic. SARS-CoV-2, the causative agent, may trigger a mild, self-limiting disease with respiratory symptoms, but patients may also succumb to a life-threatening systemic disease. The host response to the virus is equally complex and studies are now beginning to unravel the immunological correlates of COVID-19. Nanotechnology can be applied for the delivery of antiviral drugs or other repurposed drugs. Moreover, recent work has shown that synthetic nanoparticles wrapped with host-derived cellular membranes may prevent virus infection. We posit that nanoparticles decorated with ACE2, the receptor for SARS-CoV-2, could be exploited as decoys to intercept the virus before it infects cells in the respiratory tract. However, close attention should be paid to biocompatibility before such nano-decoys are deployed in the clinic.

Impact of magnetic immobilization on the cell physiology of green unicellular algae Chlorella vulgaris

Cell immobilization on the magnetic nanoparticles (MNPs) and magnetic harvesting is a novel approach for microalgal cells separation. To date, the effect of these nanoparticles on microalgal cells was only studied over a short period of time. More studies are hence needed for a better understanding of the magnetic harvesting proposes or environmental concerns relating to long-term exposure to nanoparticles. In this study, the impact of various concentrations of MNPs on the microalgal cells growth and their metabolic status was investigated over 12 days. More than 60% reduction in mitochondrial activity and pigments (chlorophyll a, chlorophyll b, and carotenoids) content occurred during the first 6 days of exposure to ≥50 µg/mL nanoparticles. However, more than 50% growth inhibitory effect was seen at concentrations higher than 400 µg/mL. Exposure to MNPs gradually induced cellular adaptation and after about 6 days of exposure to stress generating concentrations (˂400 µg/mL) of IONs, microalgae could overcome the imposed damages. This work provides a better understanding regarding the environmental impact of MNPs and appropriate concentrations of these particles for future algal cells magnetic immobilization and harvesting.

Effect of the Albumin Corona on the Toxicity of Combined Graphene Oxide and Cadmium to Daphnia magna and Integration of the Datasets into the NanoCommons Knowledge Base

In this work, we evaluated the effect of protein corona formation on graphene oxide (GO) mixture toxicity testing (i.e., co-exposure) using the Daphnia magna model and assessing acute toxicity determined as immobilisation. Cadmium (Cd2+) and bovine serum albumin (BSA) were selected as co-pollutant and protein model system, respectively. Albumin corona formation on GO dramatically increased its colloidal stability (ca. 60%) and Cd2+ adsorption capacity (ca. 4.5 times) in reconstituted water (Daphnia medium). The acute toxicity values (48 h-EC50) observed were 0.18 mg L-1 for Cd2+-only and 0.29 and 0.61 mg L-1 following co-exposure of Cd2+ with GO and BSA@GO materials, respectively, at a fixed non-toxic concentration of 1.0 mg L-1. After coronation of GO with BSA, a reduction in cadmium toxicity of 110 % and 238% was achieved when compared to bare GO and Cd2+-only, respectively. Integration of datasets associated with graphene-based materials, heavy metals and mixture toxicity is essential to enable re-use of the data and facilitate nanoinformatics approaches for design of safer nanomaterials for water quality monitoring and remediation technologies. Hence, all data from this work were annotated and integrated into the NanoCommons Knowledge Base, connecting the experimental data to nanoinformatics platforms under the FAIR data principles and making them interoperable with similar datasets.

Your Spreadsheets Can Be FAIR: A Tool and FAIRification Workflow for the eNanoMapper Database

The field of nanoinformatics is rapidly developing and provides data driven solutions in the area of nanomaterials (NM) safety. Safe by Design approaches are encouraged and promoted through regulatory initiatives and multiple scientific projects. Experimental data is at the core of nanoinformatics processing workflows for risk assessment. The nanosafety data is predominantly recorded in Excel spreadsheet files. Although the spreadsheets are quite convenient for the experimentalists, they also pose great challenges for the consequent processing into databases due to variability of the templates used, specific details provided by each laboratory and the need for proper metadata documentation and formatting. In this paper, we present a workflow to facilitate the conversion of spreadsheets into a FAIR (Findable, Accessible, Interoperable, and Reusable) database, with the pivotal aid of the NMDataParser tool, developed to streamline the mapping of the original file layout into the eNanoMapper semantic data model. The NMDataParser is an open source Java library and application, making use of a JSON configuration to define the mapping. We describe the JSON configuration syntax and the approaches applied for parsing different spreadsheet layouts used by the nanosafety community. Examples of using the NMDataParser tool in nanoinformatics workflows are given. Challenging cases are discussed and appropriate solutions are proposed.

Nanocharacterization, Materials Modeling, and Research Integrity as Enablers of Sound Risk Assessment: Designing Responsible Nanotechnology

Nanotechnology, as a mature enabling technology, has great potential to boost societal welfare. However, nanomaterials' current and foreseen applications raise serious concerns about their impact on human health and the environment. These concerns emerge because a reliable risk assessment in nanotechnology is yet to be achieved. The reasons for such a shortcoming are the inherent difficulties in characterizing nanomaterials properties. The interaction of characterization with modeling is an open issue and, due to overarching concerns about the reliability of research results, usually framed within the context of research integrity. This essay explores the connection between these different, but deeply intertwined concerns and the way they enable the production of responsible nanotechnology, i.e., nanotechnology devoted to societal welfare.

Risk Governance of Emerging Technologies Demonstrated in Terms of its Applicability to Nanomaterials

Nanotechnologies have reached maturity and market penetration that require nano-specific changes in legislation and harmonization among legislation domains, such as the amendments to REACH for nanomaterials (NMs) which came into force in 2020. Thus, an assessment of the components and regulatory boundaries of NMs risk governance is timely, alongside related methods and tools, as part of the global efforts to optimise nanosafety and integrate it into product design processes, via Safe(r)-by-Design (SbD) concepts. This paper provides an overview of the state-of-the-art regarding risk governance of NMs and lays out the theoretical basis for the development and implementation of an effective, trustworthy and transparent risk governance framework for NMs. The proposed framework enables continuous integration of the evolving state of the science, leverages best practice from contiguous disciplines and facilitates responsive re-thinking of nanosafety governance to meet future needs. To achieve and operationalise such framework, a science-based Risk Governance Council (RGC) for NMs is being developed. The framework will provide a toolkit for independent NMs' risk governance and integrates needs and views of stakeholders. An extension of this framework to relevant advanced materials and emerging technologies is also envisaged, in view of future foundations of risk research in Europe and globally.

Embedding Ethical Impact Assessment in Nanosafety Decision Support

Nanotechnology is a key enabling technology, which is developing fast and influences many aspects of life. Nanomaterials are already included in a broad range of products and industrial sectors. Nanosafety issues are still a matter of concern for policy makers and stakeholders, but currently, there is no platform where all stakeholders can meet and discuss these issues. A comprehensive overview of all the issues in one single dashboard presenting the output of a decision support system is also lacking. This article outlines a strategy for developing one innovative part of a modular decision support system, designed to support the work of a new Risk Governance Council (RGC) for nanomaterials which will be established through the combined efforts of the GOV4NANO, NANORIGO, and RiskGONE H2020 projects. This new module will consist of guidelines for Ethical Impact Assessment (EIA) for nanomaterials and nanoenabled products. This article offers recommendations for adapting the European Committee for Standardization (CEN) prestandard on Ethical Impact Assessment CWA (CEN Workshop Agreement) 17145-2:2017 (E), to fit into the more-encompassing decision support system for risk governance of nanomaterials within the RiskGONE project.

15 Years of Small: Research Trends in Nanosafety

In the field of nano- and microscale science and technology, Small has become one of the worldwide leading journals since its initiation 15 years ago. Among all the topics covered in Small, "nanosafety" has received growing interest over the years, which accounts for a large proportion of the total publications of Small. Herein, inspired by its coming Special Issue "Rethinking Nanosafety," a general bibliometric overview of the nanosafety studies that have been published in Small is presented. Using the data derived from the Web of Science Core Collection, the annual publication growth, most influential countries/institutions as well as the visualized collaborations between different countries and institutions based on CiteSpace software are presented. A special emphasis on the impact of the previous Special Issue from Small that is related to nanosafety research is given and the research trend from the most highly cited papers during last 15 years is analyzed. Lastly, future research directions are also proposed.