Evaluation and conclusions. The goal of this deliverable is to deliver a database of physicochemical properties that correlate with (eco)-toxicological endpoints by analysing research studies from literature that report information on both structural characteristics and toxicological profiles of nanomaterials. For this purpose a database structure has been developed and data has been prioritized and collected. A large amount of data has been collected that could serve this purpose. Additional activities such on database compatibility are ongoing. In a collaboration with the FP 7 eNanoMapper project the mapping of our database ontology to existing ontologies has been done. Due to small overlap with existing ontologies the eNanoMapper ontology will be expanded and an output report on the mapping will be formed by the eNanoMapper project. The full database has been shared with NANoREG partners and with the eNanoMapper project and will be made publically available as all other NANoREG data. The use and direct transfer of the WP6 literature database in the NanoReg2 and Calibrate project is currently under discussion. Focus of the work in these project is the transfer of the experimental data from NANoREG to the eNanoMapper instances. Finalization of this transfer would facilitate the transfer of the WP6 literature data to a large extend due to the strong overlap in database structure. In order to properly transfer all data and allow use of the data in these project the mapping of fields should be completed. Whether this will be done depends on the availability of resources and the expected impact of the literature data on these projects. Decisive conclusions on the use of the literature data in these project will be drawn in the first quarter of 2017. There are currently no ongoing data analysis activities.
Evaluation and conclusions. Generated data suggest a lack of serious embryotoxicity after oral and pulmonary exposure to carbon nanotubes and cerium dioxide, respectively; the observed subtle effects observed in the mother (i.e. a decreased rate of weight gaining during pregnancy) do not seem to affect the outcome of pregnancy. However, the pathophysiologic pathways underlying this phenomenon need to be explored. It remains also to be determined whether the same effect may be observed after oral and pulmonary exposure to other nanoparticles. The lack of toxic effects for the foetus after oral exposure to carbon nanotubes has been reported previously (Xxx et al 2011) at even much higher doses than those used in this project. We, however, tested for the first time the effect on the entire duration of pregnancy, starting exposure immediately after fertilization, whereas in the above-mentioned study, exposure started after the sixth day, so leaving unexplored the very early stages. We, therefore, believe that additional substantial information on the safety of exposure to carbon nanotubes during pregnancy has been added by our study. We are unaware of any data regarding the possible reproductive effects of pulmonary exposure to cerium dioxide; so our findings regarding the safety of this nanomaterial in pregnancy represent important information for exposure of pregnant women to this nanoparticle in occupational and environmental settings. From the perspective of regulators and policy makers, our data imply that unintended oral exposure to CNTs and pulmonary exposure to cerium oxide nanoparticles at doses which can be realistically expected in occupational and environmental settings should not pose peculiar risk to pregnant women. Unintended high dose (accidental) oral exposure to carbon nanotubes might have detrimental effects on gestation, and therefore close monitoring of maternal and foetal parameters should be performed.
Evaluation and conclusions. The toxic effects observed differed among the four NFCs studied, but effects were also seen with the bulk- sized cellulose studied. As concerns inflammatory effects, the mice exposed to the NFC materials and the bulk-sized cellulose showed signs of recovery of inflammation during the 28-d study period, while the MWCNT-treated mice exhibited characteristics of long-term adverse health effects. Based on the results of the present study, it seems that exposure through the respiratory tract to NFC can cause acute inflammatory responses, which, however, are not anymore present 28 d later. Although NFCs appeared to be biopersistent during this follow-up time, they induced no pathological changes observable by histological examination of the lungs. In this sense, they markedly differed from MWCNTs which still showed clear inflammatory responses 28 d after the exposure and also produced various alterations in the histology of the lungs. All NFC materials, except one, caused DNA damage in lung or BAL cells, as determined by the comet assay. For one NCF, the effect was dose-dependent in lung cells both 24 h and 28 days after the exposure. The comparative materials, bulk-sized pulp and MWCNTs, were also able to induce DNA damage after 24 h and 28 days. None of the NFCs or comparative materials was shown to possess systemic genotoxic properties, as measured by the micronucleus assay in bone marrow. The outcome of the in vivo toxicity tests was not consistently predicted by the in vitro toxicity studies reported in WP5. None of the NFCs or the bulk-sized pulp were genotoxic in vitro and only one of the NFCs was able to induce inflammatory cytokines in vitro. This comparison suggested that the mechanisms responsible for the effects observed in vivo are not fully present in the in vitro cell systems used. In the present study, exposure via the respiratory route was chosen to mimic a tentative worst-case-scenario, where liquid nanocellulose is aerosolized in the atmosphere during the manufacturing process and inhaled by workers. As NFC production is presently in an experimental phase, it is presently not known how realistic this kind of exposure scenario could be in the future production of NFC. Possible exposure routes may include, in addition to inhalation of aerosols or dry fibres, also dermal and oral exposure. Toxicological data on nanocelluloses are still scarce, which limits comparison with existing literature. Although NFC is a XXXX, nanocellulose fibres are flexi...
Evaluation and conclusions. This ProSafe work in WP3 to find a way to deploy a streamlined data management strategy by exploiting XXX-XXX-Xxxx has attracted the attention of and stimulated on-going collaboration with the US, in particular with Duke University, which has been linked to ProSafe in WP1. ProSafe recommends the European Commission to duly consider ways to further integrate the work promoted by ProSafe on data management, ISA-TAB-Nano in particular, into upcoming strategic nanoEHS R&I funding, and to link this appropriately to the burning issue of data sustainability and curation. These recommendations of this deliverable and the work on ISA-TAB-Nano serve also as input to the aspects related to data management in the ProSafe White Paper.
Evaluation and conclusions. To our knowledge, the conceptual model developed within this task is the first one to include a separate compartment for saturable phagocytic cells. This structure has later been adapted and modified in other published models, which supports its importance in nanospecific PBPK models. In agreement with the results from experimental biodistribution studies, our modelling exercises demonstrate that kinetics depends on both nanoparticles properties and exposure conditions. Despite some major achievements, these nano-PBPK models are still in their infancy and cannot yet be readily used in the regulatory arena. On the other hand, PBPK modeling provides valuable information about uptake and distribution but need to be further refined before they can be successfully used as regulatory tools. To further develop and improve the nano-PBPK models, more informative experimental biodistribution data are needed, including:
Evaluation and conclusions. Concluding remarks are in chapter 7.
Evaluation and conclusions. Inhalation is considered the gold standard for dosing the respiratory tract. The major advantage of inhalation exposure is that it mimics human pulmonary exposure by distributing the inhaled material throughout the whole respiratory tract in a physiological way over time. The work was done along two axes: - A literature review conducted in an objective to propose recommendations in terms of aerosol measurement strategy. The first objective was conducted mainly by LNE and INRS. - Experimental work with the aim to characterize different test aerosols using different generation methods to be used for inhalation studies. The second objective was conducted by the four partners INRS, LNE, LTH and NRCWE. The results clearly show several things: - For dry-based method, where mechanical forces are added to dry nanomaterial powder, and the resulting separated particles are entrained in air, the test aerosols obtained cover the particle size range from about few tens of nanometers up to several micrometers. Test aerosols are mainly composed or aggregates and/or agglomerates that composed the nanomaterial powder. The conditions required for inhalation studies (stability, repeatability, level of concentrations) are sometimes difficult to obtain, but possible. Few generation devices are commercially available. Nevertheless, it is necessary to carry out preliminary tests in order to ascertain the performances of the chosen devices and their suitability for the inhalation facility. The dry-based method, apparently easy to implement, actually requires a good level of know-how and expertise in terms of generation and characterization. - For direct-synthesis method, where airborne nanoparticles are synthesized in the gas phase and delivered to inhalation xxxxxxxx as they remain suspended, the test aerosols obtained cover the particle size range from about few nanometers up to several hundred of nanometers. Higher concentrations in number can be obtained with this method. Also stability and repeatability is generally very good. Very few generation devices are commercially available. The development of such home-made generation system is a long-term task requiring a high level of expertise in terms of generation and aerosol characterization. Altogether, the work carried out show that the generation and the characterization of the test aerosols for inhalation studies is an essential step but remains complex if one wishes to obtain robust results.
Evaluation and conclusions. The above presentation made on the basis of the analysis of the nitrogen adsorption isotherms clearly shows that it is possible to identify the nano character of a material by using the experimental VSSA criterion. To be able to do so, some conditions should be fulfilled: The particle size distribution is mono-modal The adsorption data should be of good quality as described before (effective degassing of the sample, equilibrium at each experimental point, sufficient number of experimental points to cover the relative pressure range from 0 up to 0.65). It is necessary to have an elementary knowledge of the material under test like its chemical nature, the presence of a coating and some structural data. In particular, a qualitative image by transmission electron microscopy is needed to define the particle shape. If these conditions are respected, then the analysis of adsorption isotherms via the BET and the t-plot transformations will give reliable results and the following process should be followed: If the VSSA calculated by using the BET surface area is lower than the threshold, then the sample should be considered as non-nanomaterial. If the VSSA calculated by using the BET surface area is higher than the threshold then the t-plot should be used to detect the presence of an internal porosity or the presence of a coating and to estimate the external surface of the particles as illustrated several times in this paper. This external surface is then used to calculate the VSSA which is compared to the threshold to decide if the sample is nano- or non-nano- according to the EU definition. This procedure was used in this paper and it appears that all nanomaterials were identified by this VSSA approach. To avoid the identification of false positive nano-materials, the following process should be followed: If the VSSA is lower than the threshold, then the material should be considered as non-nano. If the VSSA appears to be slightly higher (about 20%) than the threshold, it is necessary to determine the particle size distribution by TEM image analysis to decide the nano character of the material. If the VSSA is much higher than the threshold, the material should be considered as nano. This confirms that the experimental VSSA criterion is a simple practical way to assess the “non-nano” character of a powder characterised by a mono-modal particle size distribution without using expensive sophisticated methods based on number particle size distribut...
Evaluation and conclusions. Based on an extensive literature review and dialogue workshops with nanosafety researchers, this deliverable has created an inventory of the technical and social challenges that are currently inhibiting reliable safety assessment of manufactured nanomaterials, presented a characterisation of different types of uncertainty important in science for policy, and surveyed the potential of both new approaches to scientific research and to management and governance as ways to overcome the identified challenges and move forward in the face of uncertainties. In the review of two new approaches to safety testing of MNMs – high throughput screening and organ-on-a-chip – the deliverable concludes that although these approaches offer significant benefits such as a potential reduction of costs, time and animal use in safety testing, technical challenges and limitations remain concerning issues such as the regulatory acceptability of such approaches, the added value of the knowledge generated, and the relationship to real world scenarios. Having characterised various forms of uncertainty that are particularly relevant in safety assessment and that new technical approaches to safety testing cannot eliminate, the deliverable then provided a critical review of two new governance approaches seeking to manage complex risks in the face of uncertainty – Safe-by-Design and Responsible Research and Innovation. After highlighting the potential benefits and challenges associated with both approaches, this deliverable presented a way in which RRI and SbD could be combined within a stage-gate model of innovation for maximum benefit and a comprehensive assessment. This combination represents a unique contribution to the SbD stage gate model being developed within NANoREG. By including a broader range of actors and issues for consideration, it aims to enhance the potential for safe, sustainable and responsible innovation using MNMs, as called for by the European Commission. Even though challenges remain for the operationalisation and practical implementation of these new approaches to governance, the work in this deliverable offers a useful overview and critical review of the approaches and thereby a step forward towards the safe and responsible development of MNMs in the face of various forms of uncertainty. Finally this deliverable contributes in a distinctive way to the NANoREG project by offering an overview of how the challenges facing the safety assessment of MNMs that have been ...
Evaluation and conclusions. This deliverable, attempts to:
