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Burgum MJ, Ulrich C, Partosa N, Evans SJ, Gomes C, Seiffert SB, Landsiedel R, Honarvar N, Doak SH. Adapting the in vitro micronucleus assay (OECD Test Guideline No. 487) for testing of manufactured nanomaterials: recommendations for best practices. Mutagenesis 2024; 39:205-217. [PMID: 38502821 DOI: 10.1093/mutage/geae010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 03/18/2024] [Indexed: 03/21/2024] Open
Abstract
The current Organisation for Economic Co-Operation and Development test guideline number 487 (OECD TG No. 487) provides instruction on how to conduct the in vitro micronucleus assay. This assay is one of the gold standard approaches for measuring the mutagenicity of test items; however, it is directed at testing low molecular weight molecules and may not be appropriate for particulate materials (e.g. engineered nanoparticles [ENPs]). This study aimed to adapt the in vitro micronucleus assay for ENP testing and underpins the development of an OECD guidance document. A harmonized, nano-specific protocol was generated and evaluated by two independent laboratories. Cell lines utilized were human lymphoblastoid (TK6) cells, human liver hepatocytes (HepG2) cells, Chinese hamster lung fibroblast (V79) cells, whole blood, and buffy coat cells from healthy human volunteers. These cells were exposed to reference ENPs from the Joint Research Council (JRC): SiO2 (RLS-0102), Au5nm and Au30nm (RLS-03, RLS-010), CeO2 (NM212), and BaSO4 (NM220). Tungsten carbide-cobalt (WC/Co) was used as a trial particulate positive control. The chemical controls were positive in all cell cultures, but WC/Co was only positive in TK6 and buffy coat cells. In TK6 cells, mutagenicity was observed for SiO2- and both Au types. In HepG2 cells, Au5nm and SiO2 showed sub-two-fold increases in micronuclei. In V79 cells, whole blood, and buffy coat cells, no genotoxicity was detected with the test materials. The data confirmed that ENPs could be tested with the harmonized protocol, additionally, concordant data were observed across the two laboratories with V79 cells. WC/Co may be a suitable particulate positive control in the in vitro micronucleus assay when using TK6 and buffy coat cells. Detailed recommendations are therefore provided to adapt OECD TG No. 487 for testing ENP.
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Affiliation(s)
- Michael J Burgum
- In Vitro Toxicology Group, Faculty of Medicine, Health and Life Sciences, Institute of Life Sciences, Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, United Kingdom
| | - Clarissa Ulrich
- BASF SE, Experimental Toxicology and Ecology, 67056, Ludwigshafen, Germany
| | - Natascha Partosa
- BASF SE, Experimental Toxicology and Ecology, 67056, Ludwigshafen, Germany
| | - Stephen J Evans
- In Vitro Toxicology Group, Faculty of Medicine, Health and Life Sciences, Institute of Life Sciences, Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, United Kingdom
| | - Caroline Gomes
- BASF SE, Experimental Toxicology and Ecology, 67056, Ludwigshafen, Germany
| | | | - Robert Landsiedel
- BASF SE, Experimental Toxicology and Ecology, 67056, Ludwigshafen, Germany
- Free University of Berlin, Pharmacy - Pharmacology and Toxicology, 14195 Berlin, Germany
| | - Naveed Honarvar
- BASF SE, Experimental Toxicology and Ecology, 67056, Ludwigshafen, Germany
| | - Shareen H Doak
- In Vitro Toxicology Group, Faculty of Medicine, Health and Life Sciences, Institute of Life Sciences, Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, United Kingdom
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Brown S, Evans SJ, Burgum MJ, Meldrum K, Herridge J, Akinbola B, Harris LG, Jenkins R, Doak SH, Clift MJD, Wilkinson TS. An In Vitro Model to Assess Early Immune Markers Following Co-Exposure of Epithelial Cells to Carbon Black (Nano)Particles in the Presence of S. aureus: A Role for Stressed Cells in Toxicological Testing. Biomedicines 2024; 12:128. [PMID: 38255233 PMCID: PMC10813740 DOI: 10.3390/biomedicines12010128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/21/2023] [Accepted: 12/25/2023] [Indexed: 01/24/2024] Open
Abstract
The exposure of human lung and skin to carbon black (CB) is continuous due to its widespread applications. Current toxicological testing uses 'healthy' cellular systems; however, questions remain whether this mimics the everyday stresses that human cells are exposed to, including infection. Staphylococcus aureus lung and skin infections remain prevalent in society, and include pneumonia and atopic dermatitis, respectively, but current in vitro toxicological testing does not consider infection stress. Therefore, investigating the effects of CB co-exposure in 'stressed' infected epithelial cells in vitro may better approximate true toxicity. This work aims to study the impact of CB exposure during Staphylococcus aureus infection stress in A549 (lung) and HaCaT (skin) epithelial cells. Physicochemical characterisation of CB confirmed its dramatic polydispersity and potential to aggregate. CB significantly inhibited S. aureus growth in cell culture media. CB did not induce cytokines or antimicrobial peptides from lung and skin epithelial cells, when given alone, but did reduce HaCaT and A549 cell viability to 55% and 77%, respectively. In contrast, S. aureus induced a robust interleukin (IL)-8 response in both lung and skin epithelial cells. IL-6 and human beta defensin (hβD)-2 could only be detected when cells were stimulated with S. aureus with no decreases in cell viability. However, co-exposure to CB (100 µg/mL) and S. aureus resulted in significant inhibition of IL-8 (compared to S. aureus alone) without further reduction in cell viability. Furthermore, the same co-exposure induced significantly more hβD-2 (compared to S. aureus alone). This work confirms that toxicological testing in healthy versus stressed cells gives significantly different responses. This has significant implications for toxicological testing and suggests that cell stresses (including infection) should be included in current models to better represent the diversity of cell viabilities found in lung and skin within a general population. This model will have significant application when estimating CB exposure in at-risk groups, such as factory workers, the elderly, and the immunocompromised.
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Affiliation(s)
- Scott Brown
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| | - Stephen J. Evans
- In Vitro Toxicology Group, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK (M.J.D.C.)
| | - Michael J. Burgum
- In Vitro Toxicology Group, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK (M.J.D.C.)
| | - Kirsty Meldrum
- In Vitro Toxicology Group, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK (M.J.D.C.)
| | - Jack Herridge
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| | - Blessing Akinbola
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| | - Llinos G. Harris
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| | - Rowena Jenkins
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| | - Shareen H. Doak
- In Vitro Toxicology Group, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK (M.J.D.C.)
| | - Martin J. D. Clift
- In Vitro Toxicology Group, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK (M.J.D.C.)
| | - Thomas S. Wilkinson
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
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Doak SH, Andreoli C, Burgum MJ, Chaudhry Q, Bleeker EAJ, Bossa C, Domenech J, Drobne D, Fessard V, Jeliazkova N, Longhin E, Rundén-Pran E, Stępnik M, El Yamani N, Catalán J, Dusinska M. Current status and future challenges of genotoxicity OECD Test Guidelines for nanomaterials: a workshop report. Mutagenesis 2023; 38:183-191. [PMID: 37234002 PMCID: PMC10448853 DOI: 10.1093/mutage/gead017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Indexed: 05/27/2023] Open
Abstract
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.
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Affiliation(s)
- Shareen H Doak
- Institute of Life Science, Swansea University Medical School, Singelton Park, Swansea, SA2 8PP Wales, United Kingdom
| | - Cristina Andreoli
- Department of Environment and Health, Istituto Superiore di Sanità, Rome, Italy
| | - Michael J Burgum
- Institute of Life Science, Swansea University Medical School, Singelton Park, Swansea, SA2 8PP Wales, United Kingdom
| | - Qasim Chaudhry
- University of Chester, Parkgate Road, Chester, United Kingdom
| | - Eric A J Bleeker
- National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands
| | - Cecilia Bossa
- Department of Environment and Health, Istituto Superiore di Sanità, Rome, Italy
| | - Josefa Domenech
- Finnish Institute of Occupational Health, Box 40, Työterveyslaitos, 00032 Helsinki, Finland
| | - Damjana Drobne
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Vecan pot 111, 1000 Ljubljana, Slovenia
| | - Valérie Fessard
- ANSES French Agency for Food, Environmental and Occupational Health and Safety, Fougères Laboratory, Toxicology of Contaminants Unit, 10b rue Claude Bourgelat, Fougères 35306, France
| | | | - Eleonora Longhin
- NILU-Norwegian Institute for Air Research, Instituttveien 18, Kjeller 2002, Norway
| | - Elise Rundén-Pran
- NILU-Norwegian Institute for Air Research, Instituttveien 18, Kjeller 2002, Norway
| | | | - Naouale El Yamani
- NILU-Norwegian Institute for Air Research, Instituttveien 18, Kjeller 2002, Norway
| | - Julia Catalán
- Finnish Institute of Occupational Health, Box 40, Työterveyslaitos, 00032 Helsinki, Finland
- Department of Anatomy, Embryology, and Genetics, University of Zaragoza, 50013 Zaragoza, Spain
| | - Maria Dusinska
- NILU-Norwegian Institute for Air Research, Instituttveien 18, Kjeller 2002, Norway
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Siivola KM, Burgum MJ, Suárez-Merino B, Clift MJD, Doak SH, Catalán J. Correction: a systematic quality evaluation and review of nanomaterial genotoxicity studies: a regulatory perspective. Part Fibre Toxicol 2022; 19:70. [PMID: 36575483 PMCID: PMC9795579 DOI: 10.1186/s12989-022-00509-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Kirsi M. Siivola
- grid.6975.d0000 0004 0410 5926Finnish Institute of Occupational Health, Box 40, 00032 Työterveyslaitos, Helsinki, Finland
| | - Michael J. Burgum
- grid.4827.90000 0001 0658 8800In Vitro Toxicology Group, Faculty of Medicine, Health and Life Sciences, Institute of Life Sciences, Swansea University Medical School, SA2 8PP Singleton Park, Swansea, Wales, UK
| | | | - Martin J. D. Clift
- grid.4827.90000 0001 0658 8800In Vitro Toxicology Group, Faculty of Medicine, Health and Life Sciences, Institute of Life Sciences, Swansea University Medical School, SA2 8PP Singleton Park, Swansea, Wales, UK
| | - Shareen H. Doak
- grid.4827.90000 0001 0658 8800In Vitro Toxicology Group, Faculty of Medicine, Health and Life Sciences, Institute of Life Sciences, Swansea University Medical School, SA2 8PP Singleton Park, Swansea, Wales, UK
| | - Julia Catalán
- grid.6975.d0000 0004 0410 5926Finnish Institute of Occupational Health, Box 40, 00032 Työterveyslaitos, Helsinki, Finland ,grid.11205.370000 0001 2152 8769Department of Anatomy Embryology and Genetics, University of Zaragoza, 50013 Zaragoza, Spain
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Siivola KK, Burgum MJ, Suárez-Merino B, Clift MJD, Doak SH, Catalán J. A systematic quality evaluation and review of nanomaterial genotoxicity studies: a regulatory perspective. Part Fibre Toxicol 2022; 19:59. [PMID: 36104711 PMCID: PMC9472411 DOI: 10.1186/s12989-022-00499-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 08/26/2022] [Indexed: 12/29/2022] Open
Abstract
The number of publications in the field of nanogenotoxicology and the amount of genotoxicity data on nanomaterials (NMs) in several databases generated by European Union (EU) funded projects have increased during the last decade. In parallel, large research efforts have contributed to both our understanding of key physico-chemical (PC) parameters regarding NM characterization as well as the limitations of toxicological assays originally designed for soluble chemicals. Hence, it is becoming increasingly clear that not all of these data are reliable or relevant from the regulatory perspective. The aim of this systematic review is to investigate the extent of studies on genotoxicity of NMs that can be considered reliable and relevant by current standards and bring focus to what is needed for a study to be useful from the regulatory point of view. Due to the vast number of studies available, we chose to limit our search to two large groups, which have raised substantial interest in recent years: nanofibers (including nanotubes) and metal-containing nanoparticles. Focusing on peer-reviewed publications, we evaluated the completeness of PC characterization of the tested NMs, documentation of the model system, study design, and results according to the quality assessment approach developed in the EU FP-7 GUIDEnano project. Further, building on recently published recommendations for best practices in nanogenotoxicology research, we created a set of criteria that address assay-specific reliability and relevance for risk assessment purposes. Articles were then reviewed, the qualifying publications discussed, and the most common shortcomings in NM genotoxicity studies highlighted. Moreover, several EU projects under the FP7 and H2020 framework set the aim to collectively feed the information they produced into the eNanoMapper database. As a result, and over the years, the eNanoMapper database has been extended with data of various quality depending on the existing knowledge at the time of entry. These activities are highly relevant since negative results are often not published. Here, we have reviewed the NanoInformaTIX instance under the eNanoMapper database, which hosts data from nine EU initiatives. We evaluated the data quality and the feasibility of use of the data from a regulatory perspective for each experimental entry.
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Affiliation(s)
- Kirsi K. Siivola
- grid.6975.d0000 0004 0410 5926Finnish Institute of Occupational Health, Box 40, Työterveyslaitos, 00032 Helsinki, Finland
| | - Michael J. Burgum
- grid.4827.90000 0001 0658 8800In Vitro Toxicology Group, Faculty of Medicine, Health and Life Sciences, Institute of Life Sciences, Swansea University Medical School, Singleton Park, Swansea, SA2 8PP Wales UK
| | | | - Martin J. D. Clift
- grid.4827.90000 0001 0658 8800In Vitro Toxicology Group, Faculty of Medicine, Health and Life Sciences, Institute of Life Sciences, Swansea University Medical School, Singleton Park, Swansea, SA2 8PP Wales UK
| | - Shareen H. Doak
- grid.4827.90000 0001 0658 8800In Vitro Toxicology Group, Faculty of Medicine, Health and Life Sciences, Institute of Life Sciences, Swansea University Medical School, Singleton Park, Swansea, SA2 8PP Wales UK
| | - Julia Catalán
- grid.6975.d0000 0004 0410 5926Finnish Institute of Occupational Health, Box 40, Työterveyslaitos, 00032 Helsinki, Finland ,grid.11205.370000 0001 2152 8769Department of Anatomy Embryology and Genetics, University of Zaragoza, 50013 Zaragoza, Spain
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Evans SJ, Lawrence RL, Ilett M, Burgum MJ, Meldrum K, Hondow N, Jenkins GJ, Clift MJD, Doak SH. Industrial-relevant TiO 2 types do not promote cytotoxicity in the A549 or TK6 cell lines regardless of cell specific interaction. Toxicol In Vitro 2022; 83:105415. [PMID: 35752104 DOI: 10.1016/j.tiv.2022.105415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/07/2022] [Accepted: 06/04/2022] [Indexed: 01/09/2023]
Abstract
Due to the expansive application of TiO2 and its variance in physico-chemical characteristics, the toxicological profile of TiO2, in all its various forms, requires evaluation. This study aimed to assess the hazard of five TiO2 particle-types in relation to their cytotoxic profile correlated to their cellular interaction, specifically in human lymphoblast (TK6) and type-II alveolar epithelial (A549) cells. Treatment with the test materials was undertaken at a concentration range of 1-100 μg/cm2 over 24 and 72 h exposure. TiO2 interaction with both cell types was visualised by transmission electron microscopy, supported by energy-dispersive X-ray. None of the TiO2 materials tested promoted cytotoxicity in either cell type over the concentration and time range studied. All materials were observed to interact with the A549 cells and were further noted to be internalised following 24 h exposure. In contrast, only the pigmentary rutile was internalised by TK6 lymphoblasts after 24 h exposure. Where uptake was observed there was no evidence, as determined by 2D microscopy techniques, of particle localisation within the nucleus of either cell type. This study indicates that industrially relevant TiO2 particles demonstrate cell interactions that are cell-type dependent and do not induce cytotoxicity at the applied dose range.
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Affiliation(s)
- Stephen J Evans
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Rachel L Lawrence
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Martha Ilett
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK
| | - Michael J Burgum
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Kirsty Meldrum
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Nicole Hondow
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK
| | - Gareth J Jenkins
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Martin J D Clift
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Shareen H Doak
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK.
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Llewellyn SV, Parak WJ, Hühn J, Burgum MJ, Evans SJ, Chapman KE, Jenkins GJS, Doak SH, Clift MJD. Deducing the cellular mechanisms associated with the potential genotoxic impact of gold and silver engineered nanoparticles upon different lung epithelial cell lines in vitro. Nanotoxicology 2022; 16:52-72. [PMID: 35085458 DOI: 10.1080/17435390.2022.2030823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Human ENP exposure is inevitable and the novel, size-dependent physicochemical properties that enable ENPs to be beneficial in innovative technologies are concomitantly causing heightened public concerns as to their potential adverse effects upon human health. This study aims to deduce the mechanisms associated with potential ENP mediated (geno)toxicity and impact upon telomere integrity, if any, of varying concentrations of both ∼16 nm (4.34 × 10-3 to 17.36 × 10-3 mg/mL) Gold (Au) and ∼14 nm (0.85 × 10-5 to 3.32 × 10-5 mg/mL) Silver (Ag) ENPs upon two commonly used lung epithelial cell lines, 16HBE14o- and A549. Following cytotoxicity analysis (via Trypan Blue and Lactate Dehydrogenase assay), two sub-lethal concentrations were selected for genotoxicity analysis using the cytokinesis-blocked micronucleus assay. Whilst both ENP types induced significant oxidative stress, Ag ENPs (1.66 × 10-5 mg/mL) did not display a significant genotoxic response in either epithelial cell lines, but Au ENPs (8.68 × 10-3 mg/mL) showed a highly significant 2.63-fold and 2.4-fold increase in micronucleus frequency in A549 and 16HBE14o- cells respectively. It is hypothesized that the DNA damage induced by acute 24-h Au ENP exposure resulted in a cell cycle stall indicated by the increased mononuclear cell fraction (>6.0-fold) and cytostasis level. Albeit insignificant, a small reduction in telomere length was observed following acute exposure to both ENPs which could indicate the potential for ENP mediated telomere attrition. Finally, from the data shown, both in vitro lung cell cultures (16HBE14o- and A549) are equally as suitable and reliable for the in vitro ENP hazard identification approach adopted in this study.
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Affiliation(s)
- Samantha V Llewellyn
- In Vitro Toxicology Group, Institute of Life Sciences 1, Swansea University Medical School, Swansea, UK
| | - Wolfgang J Parak
- Faculty of Physics, Centre of Hybrid Nanostructures, Universität Hamburg, Hamburg, Germany
| | - Jonas Hühn
- Faculty of Physics, Philipps Universität Marburg, Marburg, Germany
| | - Michael J Burgum
- In Vitro Toxicology Group, Institute of Life Sciences 1, Swansea University Medical School, Swansea, UK
| | - Stephen J Evans
- In Vitro Toxicology Group, Institute of Life Sciences 1, Swansea University Medical School, Swansea, UK
| | - Katherine E Chapman
- In Vitro Toxicology Group, Institute of Life Sciences 1, Swansea University Medical School, Swansea, UK
| | - Gareth J S Jenkins
- In Vitro Toxicology Group, Institute of Life Sciences 1, Swansea University Medical School, Swansea, UK
| | - Shareen H Doak
- In Vitro Toxicology Group, Institute of Life Sciences 1, Swansea University Medical School, Swansea, UK
| | - Martin J D Clift
- In Vitro Toxicology Group, Institute of Life Sciences 1, Swansea University Medical School, Swansea, UK
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Burgum MJ, Clift MJD, Evans SJ, Hondow N, Miller M, Lopez SB, Williams A, Tarat A, Jenkins GJ, Doak SH. In Vitro Primary-Indirect Genotoxicity in Bronchial Epithelial Cells Promoted by Industrially Relevant Few-Layer Graphene. Small 2021; 17:e2002551. [PMID: 32734718 DOI: 10.1002/smll.202002551] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/05/2020] [Indexed: 06/11/2023]
Abstract
Few-layer graphene (FLG) has garnered much interest owing to applications in hydrogen storage and reinforced nanocomposites. Consequently, these engineered nanomaterials (ENMs) are in high demand, increasing occupational exposure. This investigation seeks to assess the inhalation hazard of industrially relevant FLG engineered with: (i) no surface functional groups (neutral), (ii) amine, and (iii) carboxyl group functionalization. A monoculture of human lung epithelial (16HBE14o- ) cells is exposed to each material for 24-h, followed by cytotoxicity and genotoxicity evaluation using relative population doubling (RPD) and the cytokinesis-blocked micronucleus (CBMN) assay, respectively. Neutral-FLG induces the greatest (two-fold) significant increase (p < 0.05) in micronuclei, whereas carboxyl-FLG does not induce significant (p < 0.05) genotoxicity. These findings correlate to significant (p < 0.05) concentration-dependent increases in interleukin (IL)-8, depletion of intracellular glutathione (rGSH) and a depletion in mitochondrial ATP production. Uptake of FLG is evaluated by transmission electron microscopy, whereby FLG particles are observed within membrane-bound vesicles in the form of large agglomerates (>1 µm diameter). The findings of the present study have demonstrated the capability of neutral-FLG and amine-FLG to induce genotoxicity in 16HBE14o- cells through primary indirect mechanisms, suggesting a possible role for carboxyl groups in scavenging radicals produced via oxidative stress.
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Affiliation(s)
- Michael J Burgum
- Institute of Life Science, Swansea University Medical School, Swansea University, Singleton Park, Swansea, Wales, SA2 8PP, UK
| | - Martin J D Clift
- Institute of Life Science, Swansea University Medical School, Swansea University, Singleton Park, Swansea, Wales, SA2 8PP, UK
| | - Stephen J Evans
- Institute of Life Science, Swansea University Medical School, Swansea University, Singleton Park, Swansea, Wales, SA2 8PP, UK
| | - Nicole Hondow
- School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Mark Miller
- Centre for Cardiovascular Science, The University of Edinburgh, Queens Medical Research Institute, Edinburgh, EH16 4TJ, UK
| | | | - Adam Williams
- Department of Physics, Swansea University, Singleton Park, Swansea, Wales, SA2 8PP, UK
| | - Afshin Tarat
- Perpetuus Carbon Technologies, Unit B1, Olympus Court, Millstream Way, Swansea Vale, Llansamlet, Swansea, SA70AQ, UK
| | - Gareth J Jenkins
- Institute of Life Science, Swansea University Medical School, Swansea University, Singleton Park, Swansea, Wales, SA2 8PP, UK
| | - Shareen H Doak
- Institute of Life Science, Swansea University Medical School, Swansea University, Singleton Park, Swansea, Wales, SA2 8PP, UK
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Burgum MJ, Clift MJD, Evans SJ, Hondow N, Tarat A, Jenkins GJ, Doak SH. Few-layer graphene induces both primary and secondary genotoxicity in epithelial barrier models in vitro. J Nanobiotechnology 2021; 19:24. [PMID: 33468168 PMCID: PMC7816456 DOI: 10.1186/s12951-021-00769-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/06/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Toxicological evaluation of engineered nanomaterials (ENMs) is essential for occupational health and safety, particularly where bulk manufactured ENMs such as few-layer graphene (FLG) are concerned. Additionally, there is a necessity to develop advanced in vitro models when testing ENMs to provide a physiologically relevant alternative to invasive animal experimentation. The aim of this study was to determine the genotoxicity of non-functionalised (neutral), amine- and carboxyl-functionalised FLG upon both human-transformed type-I (TT1) alveolar epithelial cell monocultures, as well as co-cultures of TT1 and differentiated THP-1 monocytes (d.THP-1 (macrophages)). RESULTS In monocultures, TT1 and d.THP-1 macrophages showed a statistically significant (p < 0.05) cytotoxic response with each ENM following 24-h exposures. Monoculture genotoxicity measured by the in vitro cytokinesis blocked micronucleus (CBMN) assay revealed significant (p < 0.05) micronuclei induction at 8 µg/ml for amine- and carboxyl-FLG. Transmission electron microscopy (TEM) revealed ENMs were internalised by TT1 cells within membrane-bound vesicles. In the co-cultures, ENMs induced genotoxicity in the absence of cytotoxic effects. Co-cultures pre-exposed to 1.5 mM N-acetylcysteine (NAC), showed baseline levels of micronuclei induction, indicating that the genotoxicity observed was driven by oxidative stress. CONCLUSIONS Therefore, FLG genotoxicity when examined in monocultures, results in primary-indirect DNA damage; whereas co-cultured cells reveal secondary mechanisms of DNA damage.
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Affiliation(s)
- Michael J Burgum
- Institute of Life Science, Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Martin J D Clift
- Institute of Life Science, Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Stephen J Evans
- Institute of Life Science, Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Nicole Hondow
- School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Afshin Tarat
- Perpetuus Carbon Technologies, Unit B1, Olympus Court, Millstream Way, Llansamlet, Swansea Vale, SA70AQ, UK
| | - Gareth J Jenkins
- Institute of Life Science, Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Shareen H Doak
- Institute of Life Science, Swansea University Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK.
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Evans SJ, Clift MJD, Singh N, Wills JW, Hondow N, Wilkinson TS, Burgum MJ, Brown AP, Jenkins GJ, Doak SH. In vitro detection of in vitro secondary mechanisms of genotoxicity induced by engineered nanomaterials. Part Fibre Toxicol 2019; 16:8. [PMID: 30760282 PMCID: PMC6374901 DOI: 10.1186/s12989-019-0291-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 01/29/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND It is well established that toxicological evaluation of engineered nanomaterials (NMs) is vital to ensure the health and safety of those exposed to them. Further, there is a distinct need for the development of advanced physiologically relevant in vitro techniques for NM hazard prediction due to the limited predictive power of current in vitro models and the unsustainability of conducting nano-safety evaluations in vivo. Thus, the purpose of this study was to develop alternative in vitro approaches to assess the potential of NMs to induce genotoxicity by secondary mechanisms. RESULTS This was first undertaken by a conditioned media-based technique, whereby cell culture media was transferred from differentiated THP-1 (dTHP-1) macrophages treated with γ-Fe2O3 or Fe3O4 superparamagnetic iron oxide nanoparticles (SPIONs) to the bronchial cell line 16HBE14o-. Secondly construction and SPION treatment of a co-culture model comprising of 16HBE14o- cells and dTHP-1 macrophages. For both of these approaches no cytotoxicity was detected and chromosomal damage was evaluated by the in vitro micronucleus assay. Genotoxicity assessment was also performed using 16HBE14o- monocultures, which demonstrated only γ-Fe2O3 nanoparticles to be capable of inducing chromosomal damage. In contrast, immune cell conditioned media and dual cell co-culture SPION treatments showed both SPION types to be genotoxic to 16HBE14o- cells due to secondary genotoxicity promoted by SPION-immune cell interaction. CONCLUSIONS The findings of the present study demonstrate that the approach of using single in vitro cell test systems precludes the ability to consider secondary genotoxic mechanisms. Consequently, the use of multi-cell type models is preferable as they better mimic the in vivo environment and thus offer the potential to enhance understanding and detection of a wider breadth of potential damage induced by NMs.
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Affiliation(s)
- Stephen J Evans
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Martin J D Clift
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Neenu Singh
- Faculty of Health Sciences and Life Sciences, School of Allied Health Sciences, De Montfort University, The Gateway, Leicester, LE1 9BH, UK
| | - John W Wills
- Department of Veterinary Medicine, School of Biological Sciences, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK
| | - Nicole Hondow
- School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Thomas S Wilkinson
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Michael J Burgum
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Andy P Brown
- School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Gareth J Jenkins
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Shareen H Doak
- In Vitro Toxicology Group, Institute of Life Science, Swansea Univeristy Medical School, Swansea University, Singleton Park, Swansea, SA2 8PP, Wales, UK.
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