https://cyberleninka.org/article/n/890961.pdf

A decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping)

Nanomaterials (NMs) display many unique and useful physico-chemical properties. However, reliable approaches are needed for risk assessment of NMs. The present study was performed in the FP7-MARINA project, with the objective to identify and evaluate in vitro test methods for toxicity assessment in order to facilitate the development of an intelligent testing strategy (ITS). Six representative oxide NMs provided by the EC-JRC Nanomaterials Repository were tested in nine laboratories. The in vitro toxicity of NMs was evaluated in 12 cellular models representing 6 different target organs/systems (immune system, respiratory system, gastrointestinal system, reproductive organs, kidney and embryonic tissues). The toxicity assessment was conducted using 10 different assays for cytotoxicity, embryotoxicity, epithelial integrity, cytokine secretion and oxidative stress. Thorough physico-chemical characterization was performed for all tested NMs. Commercially relevant NMs with different physico-chemical properties were selected: two TiO2 NMs with different surface chemistry – hydrophilic (NM-103) and hydrophobic (NM-104), two forms of ZnO – uncoated (NM-110) and coated with triethoxycapryl silane (NM-111) and two SiO2 NMs produced by two different manufacturing techniques – precipitated (NM-200) and pyrogenic (NM-203). Cell specific toxicity effects of all NMs were observed; macrophages were the most sensitive cell type after short-term exposures (24-72h) (ZnO>SiO2>TiO2). Longer term exposure (7 to 21 days) significantly affected the cell barrier integrity in the presence of ZnO, but not TiO2 and SiO2, while the embryonic stem cell test (EST) classified the TiO2 NMs as potentially ‘weak-embryotoxic’ and ZnO and SiO2 NMs as ‘non-embryotoxic’. A hazard ranking could be established for the representative NMs tested (ZnO NM-110 > ZnO NM-111 > SiO2 NM-203 > SiO2 NM-200 > TiO2 NM-104 > TiO2 NM-103). This ranking was different in the case of embryonic tissues, for which TiO2 displayed higher toxicity compared with ZnO and SiO2. Importantly, the in vitro methodology applied could identify cell- and NM-specific responses, with a low variability observed between different test assays. Overall, this testing approach, based on a battery of cellular systems and test assays, complemented by an exhaustive physico-chemical characterization of NMs, could be deployed for the development of an ITS suitable for risk assessment of NMs. This study also provides a rich source of data for modeling of NM effects.

/pdf/comprehensive-in-vitro-toxicity-testing-of-a-panel-of-2romhyn9vz.pdf

Comprehensive In Vitro Toxicity Testing of a Panel of Representative Oxide Nanomaterials: First Steps towards an Intelligent Testing Strategy

Numerous studies have made the ubiquitous presence of plastic in the environment undeniable, and thus it no longer comes as a surprise when scientists measure the accumulation of macroplastic litter and microplastic fragments in both urban and remote sites. Nanoplastics have recently emerged in the discussions of scientists, regulators and the public, as the weathering of macroplastics may lead to a substantial burden of nanoplastics in various ecosystems. While nanoplastics particles themselves have not (yet) been extensively measured in the environment, there is increased concern that this size fraction of plastic may be more extensively distributed and hazardous that larger-sized particles. This assessment may emanate from an unease with the term 'nano', which may elicit a negative response over uncertainties of the pervasiveness of nanoplastics specifically, or from the lessons learned by many years of intensive environmental health and safety research of engineered nanomaterials. Ultimately, the different physical and chemical characteristics of the different size classes of plastic pollution (macroplastics, microplastics and nanoplastics) will result in divergent fate and hazards. As nanoscientists specializing in understanding the fate, transport and interactions of nanoparticles in human and environmental systems, in this Perspective, we try to place nanoplastics in the context of global plastic pollution by assessing its sources and risks, and by assessing commonalities nanoplastics may share with other nanosized objects in environmental systems, such as engineered nanomaterials and natural colloids.

Placing nanoplastics in the context of global plastic pollution.

The European Union-United States Communities of Research were established in 2012 to provide a platform for scientists to develop a "shared repertoire of protocols and methods to overcome nanotechnology environmental health and safety (nanoEHS) research gaps and barriers" (www.us-eu.org/). Based on work within the Ecotoxicology Community of Research (2012-2015) the present Focus article provides an overview of the state of the art of nanomaterials (NMs) in the aquatic environment by addressing different research questions, with a focus on ecotoxicological test systems and the challenges faced when assessing NM hazards (e.g., uptake routes, bioaccumulation, toxicity, test protocols, and model organisms). The authors' recommendation is to place particular importance on studying the ecological effects of aged/weathered NMs, as-manufactured NMs, and NMs released from consumer products in addressing the following overarching research topics: 1) NM characterization and quantification in environmental and biological matrices; 2) NM transformation in the environment and consequences for bioavailability and toxicity; 3) alternative methods to assess exposure; 4) influence of exposure scenarios on bioavailability and toxicity; 5) development of more environmentally realistic bioassays; and 6) uptake, internal distribution, and depuration of NMs. Research addressing these key topics will reduce uncertainty in ecological risk assessment and support the sustainable development of nanotechnology.

/pdf/nanomaterials-in-the-aquatic-environment-a-european-union-zb3ebrv6c9.pdf

Nanomaterials in the aquatic environment: A European Union–United States perspective on the status of ecotoxicity testing, research priorities, and challenges ahead

http://nanomile.eu-vri.eu/filehandler.ashx?file=13361

A strategy for grouping of nanomaterials based on key physico-chemical descriptors as a basis for safer-by-design NMs

Background
To assess the risk of all nanomaterials (NMs) on a case-by-case basis is challenging in terms of financial, ethical and time resources. Instead a more intelligent approach to knowledge gain and risk assessment is required.

/pdf/its-nano-prioritising-nanosafety-research-to-develop-a-37aeyudpcm.pdf

Davide Roncato

Papers

ITS-NANO - Prioritising nanosafety research to develop a stakeholder driven intelligent testing strategy