The Environmental Nanoscience group at the University of Birmingham (UoB), UK, is pioneering approaches for the safe implementation of nanotechnologies and safe-by-design nanomaterials. A significant focus of the research is on generating an in-depth understanding of the interactions of nanomaterials released into the environment with the enormous diversity of biological macromolecules (proteins, polysaccharides, lipids, etc.) present in aquatic, sediment and soil environments.
These interactions can have multiple effects on the nanomaterials, including alteration of their surface chemistry, stability, transport and uptake by organisms present in the various environmental compartments. While the assessment of biomolecule interactions with nanomaterials is becoming routine in medical and human toxicological analyses, much work is still needed in the environmental or ecological context.
Understanding the nanoparticle eco-corona through EU-funded research
Through the EU’s Seventh Framework Programme (FP7) projects EcofriendlyNano, FutureNanoNeeds and NanoMILE, and through Horizon 2020 projects NanoFASE and NanoGenTools, the UoB team, under the direction of Professor Iseult Lynch, is pioneering understanding of the role of the biomolecules secreted in response to the uptake of engineered nanomaterials (the so-called ‘secretome’), and how this drives further nanomaterial uptake and mediates nanomaterial toxicity, retention, degradation or excretion, including in multi-generation tests. Our main test organisms are Daphnia magna (see Fig. 1) and biofilms, although work with other organisms is also ongoing.
Fig. 1 shows a schematic illustration of the initially acquired eco-corona that forms around nanomaterials immediately upon contact with an environmental compartment (aquatic, sediment or soil as these also have a significant fluid and biomacromolecule content) that is dependent on the organisms present and the surrounding conditions. These determine the secreted biomolecules (conditioning). Subsequent conditioning occurs as the organisms respond to the presence and uptake of nanomaterials, resulting in evolution of the nanoparticle eco-corona and further alterations in the nanomaterials’ stability, uptake and toxicity towards the organisms. Binding of key signalling molecules can potentially impact the organism’s ability to respond to threats, making them increasingly vulnerable
Methods and assays to quantify, separate or fractionate and characterise the nature of the secreted biomacromolecules are implemented and are continuously being developed. Results from the research are feeding into the modification of OECD and other standardised testing protocols for the regulatory evaluation of nanomaterials, thereby increasing community awareness of the important role of environmental macromolecules on the fate, behaviour and ecotoxicity of nanomaterials released into the environment. Such nanomaterial releases may occur intentionally (e.g. for remediation, fertilisation, pest control or other applications), unintentionally during use or at their end of life (e.g. sunscreens, cosmetics, textiles, nanomedicines, etc.), or as side products from production processes.
Eco-corona alters nanomaterial fate and effects
The ultimate goal of the Environmental Nanoscience team at the University of Birmingham is to identify key secreted biomolecules that act as markers of exposure to nanomaterials of a type that will ultimately lead to chronic toxicity or multi-generational effects, and especially those that signal within the community, triggering altered phenotypes or other population level responses. A key question the team is addressing is whether nanomaterials can impact on these signalling processes.
Important findings to date include the fact that the eco-corona formed around nanomaterials of a variety of compositions (e.g. polystyrene with different sizes and surface functionalities (see Nasser and Lynch, 2015) gold spheres or rods of different surface charges and lengths, or organic-inorganic perovskites) from biomolecules secreted by healthy Daphnia neonates result in the enhanced uptake and toxicity of the particles. In many cases, this is due to increased particle size as a result of agglomeration induced by the secreted biomolecules, which in turn results in an enhanced uptake and retention, thus allowing the impacts of the particles to be felt at lower doses. The eco-corona has also been found to enhance the bioavailability of heavy metal components of nanomaterials (publication in progress).
A key focus is on translating these important scientific questions into policy impacts, including providing thought leadership on implementable regulatory strategies, contributions to standardisation, and through engagement with a diverse panel of stakeholders across the EU. The FP7 EcofriendlyNano project facilitated the establishment of a UK-wide network of environmental nanoscientists and regulators to develop the UK’s position on a number of important issues such as the EU definition of nanomaterials for regulatory purposes, the proposed amendments to the REACH annexes for nanomaterials, the growing number of national registries for nano-containing products, and feeding UK science in this area – including specifically on eco-corona – into EU and international policy platforms. The Horizon 2020 project NanoFASE has a very strong regulatory presence in its advisory board, ensuring that all developments, including understanding the role of the eco-corona on nanomaterials’ fate and transport in the environment, feed into the regulatory models and processes effectively.
Opportunities for collaboration on understanding nanomaterials’ eco-corona
We are keen to collaborate with partners across Europe on interesting and innovative projects where our expertise in bespoke nanomaterials synthesis, labelling, characterisation, interactions with biomolecules (corona and eco-corona with “omics” abilities spanning transcriptomics, proteomics and metabolomics) and/or formulation components, toxicity or ecotoxicity assessment or modelling and regulatory knowledge could be of value. The group hosts the UK’s national Facility for Environmental Nanoscience Analysis and Characterisation (FENAC), providing access to state-of-the-art facilities, expertise and collaborative opportunities to academics and SMEs across the UK.
Based on our detailed mechanistic knowledge of how nanomaterials interact with their surroundings, we are ideally placed to harness these mechanisms for bioremediation, optimisation of ecosystems services (including improving soil structure and quality, and enhancing the yield and nutritional value of crops) and in development of replacements for so-called ‘critical materials’, through collaboration and partnerships in these areas.
To discuss potential collaborations or for more information on the nanoparticle eco-corona, please contact Iseult Lynch (firstname.lastname@example.org).
Nasser F, Lynch I. Secreted protein eco-corona mediates uptake and impacts of polystyrene nanoparticles on Daphnia magna. J Proteomics. 2016, 137:45-51.
Lynch I, Dawson KA, Lead JR, Valsami-Jones E. Macromolecular Coronas and Their Importance in Nanotoxicology and Nanoecotoxicology. In Frontiers of Nanoscience, 2014.
Valsami-Jones E, Lynch I. NANOSAFETY: How safe are nanomaterials? Science 2015, 350(6259):388-9.
Iseult Lynch, Chair of Environmental Nanoscience
School of Geography, Earth and Environmental Sciences University of Birmingham
+44 (0)121 414 5532