Food Toxicology Conference 2021

Developments in in vitro Toxicological Assessment of Nanomaterials 

 

Despite great advances in nanosafety, technical challenges remain with standard in vitro hazard evaluation strategies for nanomaterials. These tests are based on mammalian cells cultured as two dimensional (2D) monolayers, which do not closely mimic human physiology. However, cells cultured in three dimensions (3D), have increased structural complexity that is more representative of the in vivo environment. 3D tissue constructs and complex co-culture models incorporating multiple cell types therefore bridge the in vitro-to-in vivo gap for nanomaterial hazard assessment, potentially minimising animal testing. For example, co-culture models incorporating epithelial and macrophage cells can detect secondary genotoxicity, a key nanomaterial mode of action only detected in vivo. Additionally, 3D in vitro liver spheroids exhibit higher metabolic capacity, which is important for identifying pro-carcinogens. These models also support longer-term, repeated dosing, which is more representative of nanomaterial human exposure. Thus, advanced in vitro models for nanomaterial hazard assessment are supporting improved predictive toxicology.

 

Shareen Doak is Professor of Genotoxicology and Cancer in Swansea University Medical School’s In Vitro Toxicology Group. Shareen is a UK and EUROTOX Registered Toxicologist, Fellow of the Royal Society of Biology (FRSB) and Fellow of the Learned Society of Wales (FLSW). Her research interests focus on genotoxic profiles of engineered nanomaterials, mechanisms underlying their DNA damaging potential and subsequent human health consequences. Her interests extend to development of advanced 3D culture models and mechanism-based bioassays for safety assessment, to reduce the need for animal testing. Shareen sits on the UK Government Committee on Mutagenicity (COM) and is Mutagenesis Editor-in-Chief.

 

RMIT University

Overview of the Toxicological Implications of Engineered Nanomaterials in Food

 

Smart and sustainable nanotechnology product development includes the safe-by-design approach, and ethical and societal considerations – especially for food and food packaging applications. Balanced risk communication is important for addressing public concerns about nanosafety. There are many types of engineered nanomaterials; not all are alike or potential hazards. Factors for evaluating their potential risks include: intrinsic toxicity of compounds within nanomaterials; particle size, shape, surface charge and physicochemical characteristics; and exposure scenarios. Interpreting implications of nanotoxicological findings involves: (a) Nano-specific effects from comparisons with the bulk form; (b) Physicochemical characterization before, during and after exposure; (c) Weight-of-evidence approach to weigh up potential risks and benefits of using a nano-product; (d) Direct comparisons with alternatives to nano-products; (e) Clear reporting of potential risk implications to avoid misinterpretation of findings. As nanosafety remains a major concern of citizens, good governance of nanotechnologies requires appropriate nanotoxicology information for risk assessments and broad stakeholder engagement.

 

Associate Professor Paul Wright is the toxicologist at RMIT University’s School of Health and Biomedical Sciences, at Bundoora in Melbourne, Australia. Over the last three decades, Paul has been actively researching, teaching and advising government, industry and public groups in Australia and internationally about toxicology and safety issues associated with the development and use of chemicals (both natural and synthetic) and, since 2006, about nanomaterials. Paul is a Fellow and the President of the Australasian College of Toxicology and Risk Assessment (ACTRA), and a Fellow of the International Union of Pure and Applied Chemistry (IUPAC). He is also a Councillor of the International Union of Toxicology (IUTOX) and a former director of the IUTOX Executive Committee. Paul is the Co-chair of the Asia Nano Forum (ANF) Working Group on Nanosafety and Risk Management and is the nanosafety expert for the EU Horizon 2020 project “GoNano” via RMIT Europe, which has developed co-creation methodologies for nanotechnology applications in food, health and energy.

 

Singapore Food Agency

Nanomaterial Detection and Characterization in Food and Food Contact Materials

 

Nanomaterials exhibit unique physicochemical properties and innovative functions and are wildly applied in food and food contact materials (FCMs).

At present, although there has been much progress in nanotechnology, it is generally understood that some major issues still exist as the bottlenecks in achieving effective and practical testing of nanomaterials in foods and FCMs. These challenges include lack of suitable analytical methods for samples with complex matrices, lack of certified standards or reference materials, lack of validation and standardization of methods, and the lack of generic and effective sample preparation methods. 

Herein, the analytical methods and workflow for Nanomaterial Detection, Characterization in Food and FCMs have been established in NCFS/SFA by using DLS, AF4-ICP-MS, SP-ICP-MS systems. 3D information on size and size distribution, composition and concentration of nanomaterials was obtained for detection and characterization of nanomaterials in food and FCMs. 

 

Dr Yu obtained his PhD in Organic Chemistry & Material Science from Jilin University, China, in 2008, He later joined Harvard University in USA as a Postdoctoral Research Associate (2008-2010). In 2010, he joined the Institute of Bioengineering and nanotechnology (IBN) in Singapore as a Research Scientist & Project Leader (2010-2016) leading a research group to develop new organo/organometallic synergy catalytic systems for Green Synthesis and Biomass Conversion. 

Dr Yu is currently the Chemical Specialist Team Lead (2019-present) in Singapore Food Agency (SFA). The applied research strategies include forecasting food safety risks through early detection of food safety concerns and exploration of new technologies to advance in-lab and on-site rapid testing capabilities. His research interests cover 1) Non-targeted Analysis for food safety early alert, 2) Nanomaterial detection, characterization and monitoring in food and food Contact Materials and 3) Micro-/Nanoplastics detection and identification in food and water systems. 

 

 

Nanyang Technological University

 

Understanding the Relevance of Nanomaterial Transformation to Gut Nanotoxicology

 

Abstract 

Engineered nanomaterials (ENMs) are increasingly added to foods and food-contact products to improve their quality, sensory appeal, safety and shelf-life. Along with increasing utilization in agriculture, widespread human exposure to ENMs due to their transfer and bioaccumulation across the farm‐to‐fork continuum is expected. These ENMs undergo multiple physicochemical transformations (aggregation, agglomeration, dissolution, speciation change, surface modifications) along their life cycle from synthesis to consumption, which are often neglected in gut nanotoxicology studies. For example, the adsorption of food biomolecules such as bovine serum albumin and sucrose have been demonstrated to induce the disaggregation of commonly used ENM food additives, E551 SiO2 and E171 TiO2, highlighting the transformative capability of food matrices. ENMs are further transformed through the gut, as the microenvironment changes dynamically, altering their bioavailability, translocation profiles and potential toxicity. Understanding the dynamics of ENM transformations throughout their life cycle in food applications permits more realistic hazard identification.

 

A/Prof Ng Kee Woei was a recipient of the A*STAR Graduate Scholarship. In 2010, he began his tenure-track Assistant Professor position at the Nanyang Technological University (NTU), and was promoted to the position of Associate Professor with tenure in 2015. A/Prof Ng’s research interests are highly interdisciplinary. In the area of sustainable nanotechnology, he is interested in understanding the implications of exposure to engineered nanomaterials in various scenarios. Through understanding of nanomaterial behaviour, transformation and interaction with biological systems, his group targets to develop nanotechnologies that are safe to use for both humans and the environment. A/Prof Ng currently serves as a member of the Technical Committee on Nanotechnology within the Chemical Standards Committee commissioned by Enterprise SG. He is also a Subject Expert in Nanotechnology, in the SingHealth Institutional Biosafety Committee. 

 

 

Associate Professor & Deputy Director, Sydney Nano Institute 

University of Sydney 

 

Does Protein Corona Determine the Fate of Nanoparticles in Biological Systems?

 

Abstract 

Nanoparticles are increasingly used in cosmetics, food and biomedical applications. The effect of nanoparticles on human health and environment remains poorly understood. We know that physicochemical properties of nanoparticles alone cannot predict the fate of nanoparticles in biological systems. Current evidence suggests that the formation of a corona on the nanoparticle surface is the most important parameter that controls nanoparticle toxicity. While the rapid formation of corona on nanoparticles is known to influence their interactions with cells, there is a gap in fundamental understanding of how corona forms and how it remodels in microenvironment. Here we investigated how the corona develops and evolves on nanoparticles and how serum protein-corona modulates nanoparticle-cell interactions and toxicity. Through this work we demonstrated that the assessment of risks associated with nanoparticles must consider the presence of corona. This study also highlighted that precise understanding of corona formation and remodelling is likely to unlock new possibilities to manufacture safer nanoparticles for various applications.

 

Associate Professor Wojciech Chrzanowski is a Deputy Director at Sydney Nano Institute and Head of Nanomedicine and Nano-Bio-Characterisation laboratory in the Sydney School of Pharmacy, Faculty of Medicine and Health. He is a biomedical engineer who translates the science of nanoparticles and bio-characterisation at nanoscale to human applications. His work addresses a desperate need for effective nanotechnologies that regulate cells to promote desired tissue repair. Wojciech laboratory pioneers the use of nanoscale characterisation techniques to understand interactions of nanoparticles with biological systems. To this end he develops solutions to determine the safety of nanomaterials by measuring their effects in different environments. From these he learns to design less harmful nanomaterials to keep people and environment safe. Wojciech contribution to the field is exemplified by over 160 peer-reviewed publications, six patents and over 70 invited talks and seminars. He is a recipient of numerous prizes and awards for his work including 2019 Bary Inglis Medal form National Measurement Institute, 2018 Vice Chancellor’s Award for Excellence in Research and Education and 2018 Outstanding Paper Award from Royal Society of Chemistry. Translation potential of his work is demonstrated by several grant funding he received to move his research discoveries into realms of mainstream medicine.