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Di Battista V, Ribalta C, Vilsmeier K, Singh D, Demokritou P, Günther E, Jensen KA, Dekkers S, Adam V, Wohlleben W. A Screening Approach to the Safe-and-Sustainable-by-Design Development of Advanced Insulation Materials. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2311155. [PMID: 38516961 DOI: 10.1002/smll.202311155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/27/2024] [Indexed: 03/23/2024]
Abstract
Herein, a Safe-and-Sustainable-by-Design (SSbD) screening strategy on four different inorganic aerogel mats and two conventional mineral wools for ranking purposes is demonstrated. Given that they do not consist of particles, the release is first simulated, addressing three occupational exposure scenarios, realistic for their intended use as building insulators. No exposure to consumers nor to the environment is foreseen in the use phase, however, aerosols may be released during mat installation, posing an inhalation risk for workers. All four aerogel mats release more respirable dust than the benchmark materials and 60% thereof deposits in the alveolar region according to modelling tools. The collected aerogel dust allows for subsequent screening of hazard implications via two abiotic assays: 1) surface reactivity in human blood serum; 2) biodissolution kinetics in lung simulant fluids. Both aerogels and conventional insulators show similar surface reactivity. Differences in biodissolution are influenced by the specifically designed organic and inorganic structural modifications. Aerogel mats are better-performing insulators (2-fold lower thermal conductivity than the benchmark) However, this work demonstrates how investment decisions can be balanced with safety and sustainability aspects. Concepts of analogy and similarity thus support easily accessible methods to companies for safe and economically viable innovation with advanced materials.
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Affiliation(s)
- Veronica Di Battista
- Department of Analytical and Material Science and Department of Experimental Toxicology and Ecology, BASF SE, 67063, Ludwigshafen, Germany
- DTU, Department of Environmental and Resource Engineering, Kgs. Lyngby, Denmark
| | - Carla Ribalta
- National Research Centre for the Working Environment, Lerso Parkallé 105, Copenhagen, 2100, Denmark
| | - Klaus Vilsmeier
- Department of Analytical and Material Science and Department of Experimental Toxicology and Ecology, BASF SE, 67063, Ludwigshafen, Germany
| | - Dilpreet Singh
- Center for Nanotechnology and Nanotoxicology, Harvard T.H. Chan School of Public Health, Harvard University, 665 Huntington Ave., Boston, MA, 02115, USA
| | | | - Eva Günther
- BASF Construction Additives GmbH, Dr.-Albert-Frank-Str. 32, 83033, Trostberg, Germany
| | - Keld Alstrup Jensen
- National Research Centre for the Working Environment, Lerso Parkallé 105, Copenhagen, 2100, Denmark
| | - Susan Dekkers
- TNO, Unit Health Living & Work, Risk Analysis for Products in Development, Princetonlaan 6, Utrecht, 3584 CB, The Netherlands
| | - Veronique Adam
- TEMAS Solutions GmbH, Lätterweg 5, Hausen, 5212, Switzerland
| | - Wendel Wohlleben
- Department of Analytical and Material Science and Department of Experimental Toxicology and Ecology, BASF SE, 67063, Ludwigshafen, Germany
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2
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Di Cristo L, Keller JG, Leoncino L, Marassi V, Loosli F, Seleci DA, Tsiliki G, Oomen AG, Stone V, Wohlleben W, Sabella S. Critical aspects in dissolution testing of nanomaterials in the oro-gastrointestinal tract: the relevance of juice composition for hazard identification and grouping. NANOSCALE ADVANCES 2024; 6:798-815. [PMID: 38298600 PMCID: PMC10825926 DOI: 10.1039/d3na00588g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 11/07/2023] [Indexed: 02/02/2024]
Abstract
The dissolution of a nanomaterial (NM) in an in vitro simulant of the oro-gastrointestinal (OGI) tract is an important predictor of its biodurability in vivo. The cascade addition of simulated digestive juices (saliva, stomach and intestine), including inorganic/organic biomacromolecules and digestive enzymes (complete composition, referred to as "Type 1 formulation"), strives for realistic representation of chemical composition of the OGI tract. However, the data robustness requires consideration of analytical feasibility, such as the use of simplified media. Here we present a systematic analysis of the effects exerted by different digestive juice formulations on the dissolution% (or half-life values) of benchmark NMs (e.g., zinc oxide, titanium dioxide, barium sulfate, and silicon dioxide). The digestive juices were progressively simplified by removal of components such as organic molecules, enzymes, and inorganic molecules (Type 2, 3 and 4). The results indicate that the "Type 1 formulation" augments the dissolution via sequestration of ions by measurable factors compared to formulations without enzymes (i.e., Type 3 and 4). Type 1 formulation is thus regarded as a preferable option for predicting NM biodurability for hazard assessment. However, for grouping purposes, the relative similarity among diverse nanoforms (NFs) of a NM is decisive. Two similarity algorithms were applied, and additional case studies comprising NFs and non NFs of the same substance were included. The results support the grouping decision by simplified formulation (Type 3) as a robust method for screening and grouping purposes.
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Affiliation(s)
- Luisana Di Cristo
- Istituto Italiano Di Tecnologia, Nanoregulatory Group, D3PharmaChemistry Genova Italy
| | - Johannes G Keller
- Department of Material Physics and Department of Experimental Toxicology and Ecology, BASF SE Ludwigshafen Germany
| | - Luca Leoncino
- Electron Microscopy Facility, Istituto Italiano di Tecnologia Genova Italy
| | | | - Frederic Loosli
- Department of Material Physics and Department of Experimental Toxicology and Ecology, BASF SE Ludwigshafen Germany
- University of Vienna Vienna Austria
| | - Didem Ag Seleci
- Department of Material Physics and Department of Experimental Toxicology and Ecology, BASF SE Ludwigshafen Germany
| | - Georgia Tsiliki
- Institute for the Management of Information Systems, Athena Research Center Marousi Greece
| | - Agnes G Oomen
- National Institute for Public Health and the Environment (RIVM) Bilthoven The Netherlands
- University of Amsterdam Amsterdam The Netherlands
| | - Vicki Stone
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University Edinburgh UK
| | - Wendel Wohlleben
- Department of Material Physics and Department of Experimental Toxicology and Ecology, BASF SE Ludwigshafen Germany
| | - Stefania Sabella
- Istituto Italiano Di Tecnologia, Nanoregulatory Group, D3PharmaChemistry Genova Italy
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Otte JC, Hollnagel HM, Nagel C, Gerhardt RF, Wohlleben W, Vallotton N, Schowanek D, Sanders G, Frasca JM, Mahale T, Pemberton M, Hidding B, Landsiedel R. Three-tiered approach for standard information requirements for polymers requiring registration under REACH. Regul Toxicol Pharmacol 2023; 144:105495. [PMID: 37730194 DOI: 10.1016/j.yrtph.2023.105495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 09/05/2023] [Accepted: 09/13/2023] [Indexed: 09/22/2023]
Abstract
Polymers are a very large class of chemicals comprising often complex molecules with multiple functions used in everyday products. The EU Commission is seeking to develop environmental and human health standard information requirements (SIRs) for man-made polymers requiring registration (PRR) under a revised Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Regulation. Conventional risk assessment approaches currently used for small molecules may not apply to most polymers. Therefore, we propose a conceptual three-tiered regulatory approach for data generation to assess individual and groups of polymers requiring registration (PRR). A key element is the grouping of polymers according to chemistry, physico-chemical properties and hazard similarity. The limited bioavailability of many polymers is a prominent difference to many small molecules and is a key consideration of the proposed approach. Methods assessing potential for systemic bioavailability are integral to Tier 1. Decisions for further studies are based on considerations of properties and effects, combined with systemic bioavailability and use and exposure considerations. For many PRRs, Tier 1 data on hazard, use and exposure will likely be sufficient for achieving the protection goals of REACH. Vertebrate animal studies in Tiers 2 and 3 can be limited to targeted testing. The outlined approach aims to make use of current best scientific evidence and to reduce animal testing whilst providing data for an adequate level of protection.
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Affiliation(s)
- Jens C Otte
- BASF SE, Carl-Bosch-Strasse 38, 67056, Ludwigshafen am Rhein, Germany
| | | | - Christiane Nagel
- BASF SE, Carl-Bosch-Strasse 38, 67056, Ludwigshafen am Rhein, Germany
| | | | - Wendel Wohlleben
- BASF SE, Carl-Bosch-Strasse 38, 67056, Ludwigshafen am Rhein, Germany
| | | | - Diederik Schowanek
- Procter&Gamble, Brussels Innovation Centre, Temselaan 100, B-1853, Strombeek-Bever, Belgium
| | - Gordon Sanders
- Givaudan International SA, 5, Ch. de la Parfumerie, 1214, Vernier, Switzerland
| | - Joe M Frasca
- ExxonMobil Biomedical Sciences, Inc., Annandale, NJ, USA
| | - Tushar Mahale
- The Lubrizol Corporation, Advanced Materials India Pvt Ltd, 5th, 6th Floor, Jaswanti Landmark, Vikhroli, Mumbai (W), India
| | - Mark Pemberton
- Systox Limited, Sutton, Sutton Grange, Parvey Lane, SK11 0HX, Cheshire, United Kingdom
| | - Bjoern Hidding
- BASF SE, Carl-Bosch-Strasse 38, 67056, Ludwigshafen am Rhein, Germany
| | - Robert Landsiedel
- BASF SE, Carl-Bosch-Strasse 38, 67056, Ludwigshafen am Rhein, Germany; Free University of Berlin, Pharmacy, Pharmacology and Toxicology, 14195, Berlin, Germany.
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Wohlleben W, Mehling A, Landsiedel R. Lessons Learned from the Grouping of Chemicals to Assess Risks to Human Health. Angew Chem Int Ed Engl 2023; 62:e202210651. [PMID: 36254879 DOI: 10.1002/anie.202210651] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 10/15/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022]
Abstract
In analogy to the periodic system that groups elements by their similarity in structure and chemical properties, the hazard of chemicals can be assessed in groups having similar structures and similar toxicological properties. Here we review case studies of chemical grouping strategies that supported the assessment of hazard, exposure, and risk to human health. By the EU-REACH and the US-TSCA New Chemicals Program, structural similarity is commonly used as the basis for grouping, but that criterion is not always adequate and sufficient. Based on the lessons learned, we derive ten principles for grouping, including: transparency of the purpose, criteria, and boundaries of the group; adequacy of methods used to justify the group; and inclusion or exclusion of substances in the group by toxicological properties. These principles apply to initial grouping to prioritize further actions as well as to definitive grouping to generate data for risk assessment. Both can expedite effective risk management.
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Affiliation(s)
- Wendel Wohlleben
- Department of Analytical and Material Science, BASF SE, 67056, Ludwigshafen am Rhein, Germany
- Department of Experimental Toxicology and Ecology, BASF SE, 67056, Ludwigshafen am Rhein, Germany
| | - Annette Mehling
- Dept. of Advanced Formulation and Performance Technology, BASF Personal Care and Nutrition GmbH, 40589, Duesseldorf, Germany
| | - Robert Landsiedel
- Department of Experimental Toxicology and Ecology, BASF SE, 67056, Ludwigshafen am Rhein, Germany
- Free University of Berlin, Biology, Chemistry and Pharmacy-Pharmacology and Toxicology, 14195, Berlin, Germany
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5
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Di Cristo L, Ude VC, Tsiliki G, Tatulli G, Romaldini A, Murphy F, Wohlleben W, Oomen AG, Pompa PP, Arts J, Stone V, Sabella S. Grouping of orally ingested silica nanomaterials via use of an integrated approach to testing and assessment to streamline risk assessment. Part Fibre Toxicol 2022; 19:68. [PMID: 36461106 PMCID: PMC9719179 DOI: 10.1186/s12989-022-00508-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 11/21/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Nanomaterials can exist in different nanoforms (NFs). Their grouping may be supported by the formulation of hypotheses which can be interrogated via integrated approaches to testing and assessment (IATA). IATAs are decision trees that guide the user through tiered testing strategies (TTS) to collect the required evidence needed to accept or reject a grouping hypothesis. In the present paper, we investigated the applicability of IATAs for ingested NFs using a case study that includes different silicon dioxide, SiO2 NFs. Two oral grouping hypotheses addressing local and systemic toxicity were identified relevant for the grouping of these NFs and verified through the application of oral IATAs. Following different Tier 1 and/or Tier 2 in vitro methods of the TTS (i.e., in vitro dissolution, barrier integrity and inflammation assays), we generated the NF datasets. Furthermore, similarity algorithms (e.g., Bayesian method and Cluster analysis) were utilized to identify similarities among the NFs and establish a provisional group(s). The grouping based on Tier 1 and/or Tier 2 testing was analyzed in relation to available Tier 3 in vivo data in order to verify if the read-across was possible and therefore support a grouping decision. RESULTS The measurement of the dissolution rate of the silica NFs in the oro-gastrointestinal tract and in the lysosome identified them as gradually dissolving and biopersistent NFs. For the local toxicity to intestinal epithelium (e.g. cytotoxicity, membrane integrity and inflammation), the biological results of the gastrointestinal tract models indicate that all of the silica NFs were similar with respect to the lack of local toxicity and, therefore, belong to the same group; in vivo data (although limited) confirmed the lack of local toxicity of NFs. For systemic toxicity, Tier 1 data did not identify similarity across the NFs, with results across different decision nodes being inconsistent in providing homogeneous group(s). Moreover, the available Tier 3 in vivo data were also insufficient to support decisions based upon the obtained in vitro results and relating to the toxicity of the tested NFs. CONCLUSIONS The information generated by the tested oral IATAs can be effectively used for similarity assessment to support a grouping decision upon the application of a hypothesis related to toxicity in the gastrointestinal tract. The IATAs facilitated a structured data analysis and, by means of the expert's interpretation, supported read-across with the available in vivo data. The IATAs also supported the users in decision making, for example, reducing the testing when the grouping was well supported by the evidence and/or moving forward to advanced testing (e.g., the use of more suitable cellular models or chronic exposure) to improve the confidence level of the data and obtain more focused information.
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Affiliation(s)
- Luisana Di Cristo
- grid.25786.3e0000 0004 1764 2907D3 PharmaChemistry, Nanoregulatory Group, Italian Institute of Technology, Via Morego, 30, 16163 Genoa, Italy
| | - Victor C. Ude
- grid.9531.e0000000106567444Nano Safety Research Group, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, EH14 4AS UK
| | - Georgia Tsiliki
- grid.19843.370000 0004 0393 5688Institute for the Management of Information Systems, Athena Research Center, Marousi, Greece
| | - Giuseppina Tatulli
- grid.25786.3e0000 0004 1764 2907Nanobiointeractions & Nanodiagnostics, Istituto Italiano Di Tecnologia (IIT), Via Morego, 30, 16163 Genoa, Italy
| | - Alessio Romaldini
- grid.25786.3e0000 0004 1764 2907D3 PharmaChemistry, Nanoregulatory Group, Italian Institute of Technology, Via Morego, 30, 16163 Genoa, Italy
| | - Fiona Murphy
- grid.9531.e0000000106567444Nano Safety Research Group, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, EH14 4AS UK
| | - Wendel Wohlleben
- grid.3319.80000 0001 1551 0781Department Material Physics and Department of Experimental Toxicology & Ecology, BASF SE, Ludwigshafen, Germany
| | - Agnes G. Oomen
- grid.31147.300000 0001 2208 0118National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands ,grid.7177.60000000084992262Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Pier P. Pompa
- grid.25786.3e0000 0004 1764 2907Nanobiointeractions & Nanodiagnostics, Istituto Italiano Di Tecnologia (IIT), Via Morego, 30, 16163 Genoa, Italy
| | | | - Vicki Stone
- grid.9531.e0000000106567444Nano Safety Research Group, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, EH14 4AS UK
| | - Stefania Sabella
- grid.25786.3e0000 0004 1764 2907D3 PharmaChemistry, Nanoregulatory Group, Italian Institute of Technology, Via Morego, 30, 16163 Genoa, Italy
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6
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Landsiedel R, Honarvar N, Seiffert SB, Oesch B, Oesch F. Genotoxicity testing of nanomaterials. WIRES NANOMEDICINE AND NANOBIOTECHNOLOGY 2022; 14:e1833. [DOI: 10.1002/wnan.1833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/02/2022] [Accepted: 06/06/2022] [Indexed: 11/24/2022]
Affiliation(s)
- Robert Landsiedel
- Experimental Toxicology and Ecology BASF SE Ludwigshafen am Rhein Germany
- Pharmacy, Pharmacology and Toxicology Free University of Berlin Berlin Germany
| | - Naveed Honarvar
- Experimental Toxicology and Ecology BASF SE Ludwigshafen am Rhein Germany
| | | | - Barbara Oesch
- Oesch‐Tox Toxicological Consulting and Expert Opinions, GmbH & Co KG Ingelheim Germany
| | - Franz Oesch
- Oesch‐Tox Toxicological Consulting and Expert Opinions, GmbH & Co KG Ingelheim Germany
- Institute of Toxicology Johannes Gutenberg University Mainz Germany
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7
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Kodali V, Roberts JR, Glassford E, Gill R, Friend S, Dunn KL, Erdely A. Understanding toxicity associated with boron nitride nanotubes: Review of toxicity studies, exposure assessment at manufacturing facilities, and read-across. JOURNAL OF MATERIALS RESEARCH 2022; 37:4620-4638. [PMID: 37193295 PMCID: PMC10174278 DOI: 10.1557/s43578-022-00796-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 10/12/2022] [Indexed: 05/18/2023]
Abstract
Boron nitride nanotubes (BNNT) are produced by many different methods leading to variances in physicochemical characteristics and impurities in the final product. These differences can alter the toxicity profile. The importance of understanding the potential pathological implications of this high aspect ratio nanomaterial is increasing as new approaches to synthesize and purify in large scale are being developed. In this review, we discuss the various factors of BNNT production that can influence its toxicity followed by summarizing the toxicity findings from in vitro and in vivo studies conducted to date, including a review of particle clearance observed with various exposure routes. To understand the risk to workers and interpret relevance of toxicological findings, exposure assessment at manufacturing facilities was discussed. Workplace exposure assessment of BNNT from two manufacturing facilities measured boron concentrations in personal breathing zones from non-detectable to 0.95 μg/m3 and TEM structure counts of 0.0123 ± 0.0094 structures/cm3, concentrations well below what was found with other engineered high aspect ratio nanomaterials like carbon nanotubes and nanofibers. Finally, using a purified BNNT, a "read-across" toxicity assessment was performed to demonstrate how known hazard data and physicochemical characteristics can be utilized to evaluate potential inhalation toxicity concerns.
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Affiliation(s)
- Vamsi Kodali
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1000 Frederick Lane (MS-2015), Morgantown, WV 26508, USA
- Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown, WV 26506, USA
| | - Jenny R. Roberts
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1000 Frederick Lane (MS-2015), Morgantown, WV 26508, USA
| | - Eric Glassford
- Division of Field Studies and Engineering, National Institute for Occupational Safety and Health, Cincinnati, OH 45226, USA
| | - Ryan Gill
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1000 Frederick Lane (MS-2015), Morgantown, WV 26508, USA
| | - Sherri Friend
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1000 Frederick Lane (MS-2015), Morgantown, WV 26508, USA
| | - Kevin L. Dunn
- Division of Field Studies and Engineering, National Institute for Occupational Safety and Health, Cincinnati, OH 45226, USA
| | - Aaron Erdely
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1000 Frederick Lane (MS-2015), Morgantown, WV 26508, USA
- Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown, WV 26506, USA
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8
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Wohlleben W, Stone V. Editorial to the special issue on "similarity assessment of nanoforms: Concepts, tools and case studies of the GRACIOUS project". NANOIMPACT 2022; 28:100443. [PMID: 36427811 DOI: 10.1016/j.impact.2022.100443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- Wendel Wohlleben
- BASF SE, Dept. Material Physics and Dept Experimental Toxicology & Ecology, Ludwigshafen, Germany.
| | - Vicki Stone
- NanoSafety Research Group, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, UK.
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9
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Murphy F, Jacobsen NR, Di Ianni E, Johnston H, Braakhuis H, Peijnenburg W, Oomen A, Fernandes T, Stone V. Grouping MWCNTs based on their similar potential to cause pulmonary hazard after inhalation: a case-study. Part Fibre Toxicol 2022; 19:50. [PMID: 35854357 PMCID: PMC9297605 DOI: 10.1186/s12989-022-00487-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 06/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The EU-project GRACIOUS developed an Integrated Approach to Testing and Assessment (IATA) to support grouping high aspect ratio nanomaterials (HARNs) presenting a similar inhalation hazard. Application of grouping reduces the need to assess toxicity on a case-by-case basis and supports read-across of hazard data from substances that have the data required for risk assessment (source) to those that lack such data (target). The HARN IATA, based on the fibre paradigm for pathogenic fibres, facilitates structured data gathering to propose groups of similar HARN and to support read-across by prompting users to address relevant questions regarding HARN morphology, biopersistence and inflammatory potential. The IATA is structured in tiers, allowing grouping decisions to be made using simple in vitro or in silico methods in Tier1 progressing to in vivo approaches at the highest Tier3. Here we present a case-study testing the applicability of GRACIOUS IATA to form an evidence-based group of multiwalled carbon nanotubes (MWCNT) posing a similar predicted fibre-hazard, to support read-across and reduce the burden of toxicity testing. RESULTS The case-study uses data on 15 different MWCNT, obtained from the published literature. By following the IATA, a group of 2 MWCNT was identified (NRCWE006 and NM-401) based on a high degree of similarity. A pairwise similarity assessment was subsequently conducted between the grouped MWCNT to evaluate the potential to conduct read-across and fill data gaps required for regulatory hazard assessment. The similarity assessment, based on expert judgement of Tier 1 assay results, predicts both MWCNT are likely to cause a similar acute in vivo hazard. This result supports the possibility for read-across of sub-chronic and chronic hazard endpoint data for lung fibrosis and carcinogenicity between the 2 grouped MWCNT. The implications of accepting the similarity assessment based on expert judgement of the MWCNT group are considered to stimulate future discussion on the level of similarity between group members considered sufficient to allow regulatory acceptance of a read-across argument. CONCLUSION This proof-of-concept case-study demonstrates how a grouping hypothesis and IATA may be used to support a nuanced and evidence-based grouping of 'similar' MWCNT and the subsequent interpolation of data between group members to streamline the hazard assessment process.
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Affiliation(s)
- Fiona Murphy
- NanoSafety Group, Heriot-Watt University, Edinburgh, UK.
| | | | - Emilio Di Ianni
- National Research Centre for the Working Environment (NFA), Copenhagen, Denmark
| | | | - Hedwig Braakhuis
- National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Willie Peijnenburg
- National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.,Institute of Environmental Sciences, Leiden University, Leiden, The Netherlands
| | - Agnes Oomen
- National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | | | - Vicki Stone
- NanoSafety Group, Heriot-Watt University, Edinburgh, UK
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10
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Cross RK, Bossa N, Stolpe B, Loosli F, Sahlgren NM, Clausen PA, Delpivo C, Persson M, Valsesia A, Ponti J, Mehn D, Seleci DA, Müller P, von der Kammer F, Rauscher H, Spurgeon D, Svendsen C, Wohlleben W. Reproducibility of methods required to identify and characterize nanoforms of substances. NANOIMPACT 2022; 27:100410. [PMID: 35787478 DOI: 10.1016/j.impact.2022.100410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 06/24/2022] [Accepted: 06/25/2022] [Indexed: 06/15/2023]
Abstract
Nanoforms (NFs) of a substance may be distinguished from one another through differences in their physicochemical properties. When registering nanoforms of a substance for assessment under the EU REACH framework, five basic descriptors are required for their identification: composition, surface chemistry, size, specific surface area and shape. To make the risk assessment of similar NFs efficient, a number of grouping frameworks have been proposed, which often require assessment of similarity on individual physicochemical properties as part of the group justification. Similarity assessment requires an understanding of the achievable accuracy of the available methods. It must be demonstrated that measured differences between NFs are greater than the achievable accuracy of the method, to have confidence that the measured differences are indeed real. To estimate the achievable accuracy of a method, we assess the reproducibility of six analytical techniques routinely used to measure these five basic descriptors of nanoforms: inductively coupled plasma mass spectrometry (ICP-MS), Thermogravimetric analysis (TGA), Electrophoretic light scattering (ELS), Brunauer-Emmett-Teller (BET) specific surface area and transmission and scanning electron microscopy (TEM and SEM). Assessment was performed on representative test materials to evaluate the reproducibility of methods on single NFs of substances. The achievable accuracy was defined as the relative standard deviation of reproducibility (RSDR) for each method. Well established methods such as ICP-MS quantification of metal impurities, BET measurements of specific surface area, TEM and SEM for size and shape and ELS for surface potential and isoelectric point, all performed well, with low RSDR, generally between 5 and 20%, with maximal fold differences usually <1.5 fold between laboratories. Applications of technologies such as TGA for measuring water content and putative organic impurities, additives or surface treatments (through loss on ignition), which have a lower technology readiness level, demonstrated poorer reproducibility, but still within 5-fold differences. The expected achievable accuracy of ICP-MS may be estimated for untested analytes using established relationships between concentration and reproducibility, but this is not yet the case for TGA measurements of loss on ignition or water content. The results here demonstrate an approach to estimate the achievable accuracy of a method that should be employed when interpreting differences between NFs on individual physicochemical properties.
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Affiliation(s)
- Richard K Cross
- UK Centre for Ecology and Hydrology, Pollution, Wallingford, Oxfordshire, United Kingdom.
| | - Nathan Bossa
- LEITAT Technological Center, Carrer de la Innovació 2, 08225 Terrassa, Barcelona, Spain
| | | | - Frédéric Loosli
- Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, Wien, Austria
| | | | - Per Axel Clausen
- The National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Camilla Delpivo
- LEITAT Technological Center, Carrer de la Innovació 2, 08225 Terrassa, Barcelona, Spain
| | | | - Andrea Valsesia
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Jessica Ponti
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Dora Mehn
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Didem Ag Seleci
- BASF SE, Department of Material Physics and Department of Experimental Toxicology & Ecology, Ludwigshafen, Germany
| | - Philipp Müller
- BASF SE, Department of Material Physics and Department of Experimental Toxicology & Ecology, Ludwigshafen, Germany
| | - Frank von der Kammer
- Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, Wien, Austria
| | - Hubert Rauscher
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Dave Spurgeon
- UK Centre for Ecology and Hydrology, Pollution, Wallingford, Oxfordshire, United Kingdom
| | - Claus Svendsen
- UK Centre for Ecology and Hydrology, Pollution, Wallingford, Oxfordshire, United Kingdom
| | - Wendel Wohlleben
- BASF SE, Department of Material Physics and Department of Experimental Toxicology & Ecology, Ludwigshafen, Germany
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11
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A Decision Support System for preclinical assessment of nanomaterials in medical products: the REFINE DSS. Drug Deliv Transl Res 2022; 12:2101-2113. [PMID: 35538190 PMCID: PMC9089298 DOI: 10.1007/s13346-022-01145-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2022] [Indexed: 11/03/2022]
Abstract
The application of nanomaterials in medicine has led to novel pharmaceuticals and medical devices that have demonstrated a strong potential for increasing the efficacy/performance and safety of therapeutic and diagnostic procedures to address a wide range of diseases. However, the successful translation of these technologies from their inception (proof-of-concept) to clinical practice has been challenged by substantial gaps in the scientific and technical capacity of R&D companies, especially SMEs, to keep up with the ever-evolving regulatory expectations in the emerging area of nanomedicine. To address these challenges, the EU Horizon 2020 project REFINE has developed a Decision Support System (DSS) to support developers of nanotechnology-enabled health products in bringing their products to the clinic. The REFINE DSS has been developed to support experts, innovators, and regulators in the implementation of intelligent testing strategies (ITS) for efficient preclinical assessment of nanotechnology-enabled health products. The DSS applies logical rules provided by REFINE experts which generate prioritized lists of assays to be performed (i.e. ITSs) for physicochemical characterisation and for immunotoxicological endpoints. The DSS has been tested against several case studies and was validated by internal project experts as well as external ones.
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12
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Basei G, Rauscher H, Jeliazkova N, Hristozov D. A methodology for the automatic evaluation of data quality and completeness of nanomaterials for risk assessment purposes. Nanotoxicology 2022; 16:195-216. [PMID: 35506346 DOI: 10.1080/17435390.2022.2065222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This manuscript proposes a methodology to assess the completeness and quality of physicochemical and hazard datasets for risk assessment purposes. The approach is also specifically applicable to similarity assessment as a basis for grouping of (nanoforms of) chemical substances as well as for classification of the substances according to the Classification, Labeling and Packaging regulation. The unique goal of this approach is to assess data quality in such a way that all the steps are automatized, thus reducing reliance on expert judgment. The analysis starts from available (meta)data as provided in the data entry templates developed by the NanoSafety community and used for import into the eNanoMapper database. The methodology is implemented in the templates as a traffic light system-the providers of the data can see in real time the completeness scores calculated by the system for their datasets in green, yellow, or red. This is an interactive feedback feature that is intended to provide an incentive for anyone inserting data into the database to deliver more complete and higher quality datasets. The users of the data can also see this information both in the data entry templates and on the database interface, which enables them to select better datasets for their assessments. The proposed methodology has been partially implemented in the eNanoMapper database and in a Weight of Evidence approach for the regulatory classification of nanomaterials. It was fully implemented in a publicly available online R tool.
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Affiliation(s)
| | - Hubert Rauscher
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | | | - Danail Hristozov
- GreenDecision Srl, Mestre, Italy.,East European Research and Innovation Enterprise, Sofia, Bulgaria
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13
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Zheng Y, Nowack B. Meta-analysis of Bioaccumulation Data for Nondissolvable Engineered Nanomaterials in Freshwater Aquatic Organisms. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:1202-1214. [PMID: 35188281 PMCID: PMC9314877 DOI: 10.1002/etc.5312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/27/2022] [Accepted: 02/15/2022] [Indexed: 06/07/2023]
Abstract
Understanding the bioaccumulation of engineered nanomaterials (ENMs) is essential for making regulatory decisions on potential environmental risks. Research in the field of ENM bioaccumulation has increased in recent years, but the compilation and statistical analysis of the available experimental data have not been updated. We therefore performed a meta-analysis of the existing literature on the bioaccumulation of eight types of nondissolvable ENMs (titanium dioxide [TiO2 ], aluminum oxide [Al2 O3 ], gold [Au], fullerene [C60 ], carbon nanotubes, iron oxide [FeOx ], graphene, and polystyrene) in nonmammalian freshwater aquatic organisms across three trophic levels including phytoplankton, zooplankton, and fish. Three typical endpoints were used to assess the bioaccumulation potential: the bioconcentration factor (BCF), the bioaccumulation factor (BAF), and the biomagnification factor (BMF). Our results suggest that zooplankton has greater mean logarithmic BCF and BAF values than phytoplankton (3.31 vs. 1.42) and fish (2.04). The ENMs are biomagnified in zooplankton, with a mean BMF of 17.4, whereas trophic transfer from primary consumers (zooplankton) to secondary consumers (fish) was not observed (mean BMF of 0.13). No clear dependency was identified between the physicochemical characteristics of ENMs (e.g., primary particle size, zeta potential, or shape) and bioaccumulation, except for coated versus uncoated particles accumulated in phytoplankton. Carbonaceous ENMs were found to be more bioaccumulated than the other ENMs we considered, except for TiO2 . A meta-analysis of bioaccumulation data can (1) deepen the understanding of bioconcentration, bioaccumulation, and biomagnification of ENMs, (2) be used to support grouping strategies as a basis for a safer-by-design approach for ENMs, (3) be integrated into comprehensive hazard and risk assessments, (4) promote the standardization of testing guidelines, and (5) enhance future kinetic bioaccumulation modeling. Environ Toxicol Chem 2022;41:1202-1214. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
- Yuanfang Zheng
- Technology and Society LabSwiss Federal Laboratories for Materials Science and TechnologyGallenSwitzerland
| | - Bernd Nowack
- Technology and Society LabSwiss Federal Laboratories for Materials Science and TechnologyGallenSwitzerland
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14
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Cross R, Matzke M, Spurgeon D, Diez M, Andres VG, Galvez EC, Esponda MF, Belinga-Desaunay-Nault MF, Lynch I, Jeliazkova N, Svendsen C. Assessing the similarity of nanoforms based on the biodegradation of organic surface treatment chemicals. NANOIMPACT 2022; 26:100395. [PMID: 35560293 DOI: 10.1016/j.impact.2022.100395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 02/22/2022] [Accepted: 03/11/2022] [Indexed: 06/15/2023]
Abstract
A substance may have one or more nanoforms, defined for regulatory purposes under EU chemicals legislation REACH based on differences in physicochemical properties such as size, shape, specific surface area and surface chemistry including coatings. To reduce the burden of testing each unique nanoform for the environmental risk assessment of nanomaterials, grouping approaches allow simultaneous assessment of multiple nanoforms. Nanoforms with initially different intrinsic properties, could still be considered similar if their environmental fate and effects can be demonstrated to be similar. One hypothesis to group nanoforms with different organic surface modifications is to use parameters linked to biodegradation of the organic surface. The hypothesis contends that nanoforms with a similar core chemistry, but different organic surface treatments may be grouped, if the surface treatment is likely to be lost through biodegradation rapidly upon entering an environmental compartment, such that it no longer modulates fate, exposure and toxicity of the nanoform. To implement grouping according to surface treatment biodegradability, a robust approach to measure the breakdown of particle surface treatments is needed. We present a tiered testing strategy to assess the biodegradation of organic surface treatments used with nanomaterials that can be implemented as part of an Integrated Approach to Testing and Assessment (IATA) for grouping based on surface treatment stability. The tiered approach consists of an initial pre-screening MT2 colorimetric carbon substrate utilisation assay, to provide a rapid assessment of coating degradation, and a second tier of testing using OECD Test Guideline 301F for assessing organic chemical biodegradability. Six common surface treatment substances are assessed using the tiered testing strategy to refine rules for escalating between tiers. Similarity assessment using absolute Euclidean distances and x-fold difference concluded that the Tier 1 assessment can be used as conservative binary screening for biodegradability (no false positive results in Tier 1), whilst for substances showing intermediate biodegradation (10-60% in OECD 301F, Tier 2), similarity assessments can be informative for grouping surface treatments not considered readily biodegradable. Further validation using higher tier tests (e.g., mesocosms) is needed to define acceptable limits of similarity between intermediately biodegradable substances, where differences in biodegradability of the surface coating lead to negligible differences in fate, behaviour and toxicity of the nanoforms, and this is critically discussed.
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Affiliation(s)
- Richard Cross
- UK Centre for Ecology and Hydrology, Wallingford, United Kingdom.
| | - Marianne Matzke
- UK Centre for Ecology and Hydrology, Wallingford, United Kingdom
| | - Dave Spurgeon
- UK Centre for Ecology and Hydrology, Wallingford, United Kingdom
| | - María Diez
- LEITAT Technological Center, Carrer de la Innovació 2, Terrassa, 08225, Barcelona, Spain
| | | | - Elena Cerro Galvez
- LEITAT Technological Center, Carrer de la Innovació 2, Terrassa, 08225, Barcelona, Spain
| | - Maria Fernanda Esponda
- LEITAT Technological Center, Carrer de la Innovació 2, Terrassa, 08225, Barcelona, Spain
| | | | - Iseult Lynch
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | | | - Claus Svendsen
- UK Centre for Ecology and Hydrology, Wallingford, United Kingdom
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15
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Jeliazkova N, Ma-Hock L, Janer G, Stratmann H, Wohlleben W. Possibilities to group nanomaterials across different substances - A case study on organic pigments. NANOIMPACT 2022; 26:100391. [PMID: 35560297 DOI: 10.1016/j.impact.2022.100391] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 06/15/2023]
Abstract
Grouping concepts to reduce the testing of NFs have been developed for regulatory purposes for different forms of the same substance. Here we explore possibilities to group nanomaterials across different substances for non-regulatory applications, using the example of 16 organic pigments from six chemical classes. Organic pigments are particles consisting of low-molar-mass organic molecules, and rank by tonnage among the most important substances manufactured in nanoform (NF). Tiered testing strategies relevant to the inhalation route included Tier 1 (deposition, dissolution, reactivity, inflammation) and if available Tier 3 data (in vivo). A similarity assessment of the pigment NF data was conducted in a quantitative (Tier 1 and Tier 3 in vivo potency) or qualitative (Tier 3 in vivo effects) manner. We observed that chemical similarity of organic pigments was predictive for their similarity of reactivity and dissolution, but that additional NF descriptors such as surface area or size, modulate the similarity in inflammation or cytotoxicity. We applied the concept of biologically relevant ranges to crop the values of the Tier 1 data matrix before applying similarity algorithms. The Tier 3 assessment by in vivo inhalation confirmed the IATA methodical choices and IATA assessment criteria as consistent and conservative. We suggested limits of acceptable similarity for Tier 1 data and demonstrated their application to support the grouping of some candidate NFs (subsequently confirmed by Tier 3 data). Four candidate NFs exceeded the limits of acceptability for Tier 1 and were escalated from Tier 1 to Tier 3, but were then included in the group, demonstrating the conservative Tier 1 criteria. The resulting group of low-solubility, low-reactivity materials included both NFs and non-NFs of various substances, and could find use for risk management purposes in the occupational handling of pigment powders.
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Affiliation(s)
| | - Lan Ma-Hock
- BASF SE, Dept Experimental Toxicology & Ecology, Ludwigshafen, Germany
| | - Gemma Janer
- LEITAT Technological Center, Barcelona, Spain
| | | | - Wendel Wohlleben
- BASF SE, Dept Experimental Toxicology & Ecology, Ludwigshafen, Germany; BASF SE, Dept. Material Physics, Ludwigshafen, Germany.
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16
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Ag Seleci D, Tsiliki G, Werle K, Elam DA, Okpowe O, Seidel K, Bi X, Westerhoff P, Innes E, Boyles M, Miller M, Giusti A, Murphy F, Haase A, Stone V, Wohlleben W. Determining nanoform similarity via assessment of surface reactivity by abiotic and in vitro assays. NANOIMPACT 2022; 26:100390. [PMID: 35560290 DOI: 10.1016/j.impact.2022.100390] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 06/15/2023]
Abstract
Grouping of substances is a method used to streamline hazard and risk assessment. Assessment of similarity provides the scientific evidence needed for formation of groups. This work reports on justification of grouping of nanoforms (NFs) via similarity of their surface reactivity. Four reactivity assays were used for concentration dependent detection of reactive oxygen species (ROS) generated by NFs: abiotic assays FRAS, EPR and DCFH2-DA, as well as the in vitro assay of NRF2/ARE responsive luciferase reporter activation in the HEK293 cell line. Representative materials (CuO, Mn2O3, BaSO4, CeO2 and ZnO) and three case studies of each several NFs of iron oxides, Diketopyrrolopyrroles (DPP)-based organic pigments and silicas were assessed. A novel similarity assessment algorithm was applied to quantify similarities between pairs of NFs, in a four-step workflow on concentration-response curves, individual concentration and response ranges, and finally the representative materials. We found this algorithm to be applicable to all abiotic and in vitro assays that were tested. Justification of grouping must include the increased potency of smaller particles via the scaling of effects with specific surface, and hence quantitative similarity analysis was performed on concentration-response in mass-metrics. CuO and BaSO4 were the most and least reactive representative materials respectively, and all assays found BaSO4/CuO not similar, as confirmed by their different NOAECs of in vivo studies. However, similarity outcomes from different reactivity assays were not always in agreement, highlighting the need to generate data by one assay for the representative materials and the candidate group of NFs. Despite low similarity scores in vitro some pairs of case study NFs can be accepted as sufficiently similar because the in vivo NOAECs are similar, highlighting the conservative assessment by the abiotic assays.
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Affiliation(s)
- Didem Ag Seleci
- Advanced Materials Research, Dept. of Material Physics and Analytics and Dept. of Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany
| | | | - Kai Werle
- Advanced Materials Research, Dept. of Material Physics and Analytics and Dept. of Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany
| | - Derek A Elam
- Advanced Materials Research, Dept. of Material Physics and Analytics and Dept. of Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany
| | - Omena Okpowe
- Advanced Materials Research, Dept. of Material Physics and Analytics and Dept. of Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany
| | - Karsten Seidel
- Advanced Materials Research, Dept. of Material Physics and Analytics and Dept. of Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany
| | - Xiangyu Bi
- Advanced Materials Research, Dept. of Material Physics and Analytics and Dept. of Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany; School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, USA
| | - Paul Westerhoff
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, USA
| | - Emma Innes
- Institute of Occupational Medicine, Edinburgh, United Kingdom
| | - Matthew Boyles
- Institute of Occupational Medicine, Edinburgh, United Kingdom
| | - Mark Miller
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
| | - Anna Giusti
- German Federal Institute for Risk Assessment, Department of Chemical and Product Safety, Berlin, Germany
| | - Fiona Murphy
- NanoSafety Group, Heriot-Watt University, Edinburgh, United Kingdom
| | - Andrea Haase
- German Federal Institute for Risk Assessment, Department of Chemical and Product Safety, Berlin, Germany
| | - Vicki Stone
- NanoSafety Group, Heriot-Watt University, Edinburgh, United Kingdom
| | - Wendel Wohlleben
- Advanced Materials Research, Dept. of Material Physics and Analytics and Dept. of Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany.
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