Evaluation and conclusions. The objectives presented in the deliverable description aiming to develop and validate SOPs for quantitative TEM analysis of MNM were reached. SOPs for quantitative TEM analysis of MNM were developed. These SOPs were validated by application on a series of nanomaterials of various types and sizes, by intra-laboratory and inter- laboratory validation based on the estimation of the measurement uncertainties. These SOPS allow to estimate the minimal external dimension of NM such that the EC definition for NM can be implemented for a wide selection of colloidal and aggregated fractal-like nanomaterials with known measurement uncertainties. Further a large panel of size and shape measurands with measurement uncertainties were determined for these materials, resulting in a detailed characterization required for e.g. risk analyses. The SOP to prepare a TEM specimen suitable for qualitative and quantitative analysis from a dispersed NM ensures that the NM samples are suitable for TEM imaging and analysis. The examined materials were evenly distributed over the grids and the fraction of the attached NM represents the dispersed NM optimally. The SOP to record a set of calibrated transmission electron micrographs showing NM that are representative for the NM on the EM grid ensures that the number of particles and the magnification of the micrographs are suitable for subsequent descriptive and quantitative image analyses. The method for characterizing the primary particles and aggregates of a NM by describing their physical properties based on TEM micrographs provides a step-by-xxxx xxxxx for the descriptive characterization of nanomaterials. The SOPs to analyze the 2D properties of the primary and aggregated/agglomerated particles on EM micrographs ensure that the primary particles are detected and that size and shape measurands are determined quantitatively. A modified version allows to measure the size and shape properties of the aggregates/agglomerates. Data were analyzed and represented according to relevant ISO-norms. The EM-based results were related to the results obtained with alternative methods. These include ensemble techniques based on light scattering, such as dynamic light scattering (DLS) and particle tracking analysis (PTA), and single particle inductively coupled plasma-mass spectrometry (SP-ICP- MS) [1]. Our work illustrates that the size measurands measured with the different techniques are method- defined and cannot be directly compared ...
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 proposed NANoREG foresight system makes use of well-known and accepted concepts to assess the potential impacts of future innovations linked to new nanomaterials. The framework and the system are a first step toward nanotechnology innovation monitoring. The reference to methods, models and tools developed or applied in NANoREG represents a first idea of what kind of approaches can be used to carry out the analysis. The case study exercise also highlighted that to implement such a system for innovation monitoring it is necessary the cooperation of experts in different fields, in order to collect and evaluate data and information which are qualitative in nature. Also, a great deal of expert judgement is necessary to evaluate the risk hypotheses and define the priorities. The work done in D6.1 is linked to SbD, and in a RRI context, it is placed as analysis tool to assess potential applications of nanomaterials, up to the idea stage of the innovation stage- gate approach. Also, the inclusion of regulators and other stakeholders in this system is supporting the following Trusted Environments creation which is part of the regulatory preparedness of the Safe Innovation Approach.
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. Concluding remarks are in chapter 7.
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:
1) extensive characterization
2) monitoring of several organs at several time-points
3) frequent sampling immediately after dosing
4) long follow-up post-dosing
5) account for mass balance (total recovery)
6) detailed description of the analytical procedures
Evaluation and conclusions. Even though there was a substantial delay in the preparation of the call, the work is on track and the call will be launched based on a wide consensus among the stakeholders involved. The number of funding organisations is still a critical issue, but the minimum amount of partners has been reached.
Evaluation and conclusions. This deliverable provides a test for the NANoREG SVCCS approach. Several candidate SVCCSs have been proposed and subjected for scrutiny regarding their intrinsic value and the realism and conditions for performing them. Those that have been submitted to the NANoREG MC for approval have been initiated and, in the case of GALANT, CNT/Graphene and nano-TiO2 in honeycombs also performed and finalised. Based on this experience, the procedure for acquisition and approval of SVCCS is sound. It is realistic to address specific parts of or an entire value chain if experimental work is planned. The outcome of the SVCCSs furthermore shows that it is possible to perform relevant work addressing “real” issues from the perspective of the stakeholder of the value chain. Furthermore, the work with these studies revealed that unexpected practical problems arise that not necessarily would appear in a more traditional academic type of research project. The connection between these studies and the NANoREG regulatory questions will be further discussed in the Deliverable 1.8.
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. There is an ongoing growth in Nanotechnology where MNMs are more often coming into contact with humans and the environment. The interface between any type of nanomaterial with the surrounding environment either proteins/cells in a culture medium or bound to a matrix/composite or in a solvent depends on colloidal forces as well as dynamic biophysicochemical interactions. The development of predictive relationships between structure (key parameter) of nanomaterials and activity (functionality) are determined by nanomaterial properties. The key parameters of size, shape, composition, surface charge, aggregation, test medium (in our case water) are the priority parameters affecting all the functionalities; while the rest of parameters are of importance. The understanding of these relationships is very important from the perspective of safe use of nano materials. It is not possible to describe all the biophysicochemical interactions at the interface, but we made an effort to assemble knowledge and information to provide a framework to guide this exploration. The literature study consisted of about 140 papers, mainly reporting on CNTs; ZnO, SiO2, Ag and then the rest of MNMs; a priority list was formulated focusing on the core nanomaterials of NANoREG project; the publication year in order to have as recent as possible literature data; and the key physicochemical parameters as showed in other deliverables of WP6 including toxicity. The main finding from D6.3 was a list of risk potentials, which in our case involve our functionalities such as solubility/dissolution, that needs to be screened during the development of toxicity testing. D6.6 is part of the NANoREG project aimed to provide some consensus on which key parameters of MNMs affect specific functionalities in an attempt to establish a relation between them and to propose a workable data model. This is one of the first attempts to identify the main key properties of the MNMs that in relation to their functionalities play a dominant role on the safe by design. This proposed data model is considered as one of the possible approaches towards a decision tree strategy for (re)designing safe MNMs for humans and the environment which will be established in NanoReg2 project. The optimal design of safe nanomaterials is a challenge with multiple compromises between functionality and safety characteristics.
