Research projects

A study of the nanoscale properties of archaeological medicinal ‘earths’

Effie Photos-Jones

Early pharmacological texts and the pharmacopoeias of later periods often refer to a collection of minerals with medicinal properties called “earths” in the form of stamped clay tablets, dated to c. 16^th-17^th century, and originating from the island of Lemnos, have undergone microbiological testing and have been shown to be active against Staphylococcus aureus.  A parallel examination of five samples of ‘soils’ from the purported area of the extraction of these tablets showed no antibacterial action.  Comparison between XRD/ICP-MS of both ancient artefacts and modern ‘soils’ show that there are no substantial differences between the two groups.  Have the ‘ancient’ artefacts undergone an enrichment stage which has differentiated the finished product from the raw material, to the extent of altering its physico-chemical and by extension antibacterial properties?  This pilot study on the nanoscale properties of three clay tablets is part of a larger project into the nature and properties of the earths of the Aegean, which include layered silicates, borates and sulphates.  It asks the question:  do nanoscale characteristics influence the earths’ properties as antibacterial/antifungals or other? 

Characterisation of biogenic nanoparticles from metal-contaminated land, water and waste

Louise Horsfall

We are investigating the bacterial synthesis of metal nanoparticles to exploit this natural phenomenon to recover metals from land, water and waste.  

We produce nanoparticles of Cu, Ag, As(0) and Ni(0) using bacteria; this project would focus on characterising the biogenenic nanoparticles and their corona or biological coating, as this may affect their physicochemical properties and hence their possible industrial applications and toxicity in the environment.  We wish to propose this as a method to recycle metals from waste, but prior to that we propose that we should be responsible in our innovations and therefore need a better understanding of biological and environmental impacts of nanoparticles of biogenic origin. 

Manganese oxide nanoparticles in peaty water 

Karen Johnson

Significant organic carbon (OC) is being removed in a NE Water Treatment Works by manganese oxide filter beds (3%w/w Carbon) and the authors proposed that stabilisation is occurring by physical entrapment and chemical bonding (Johnson et al, 2015)¹_.  The WTW is fed by peaty water in the North Pennines and up to 90% of the total influent Mn is <0.2 µm.  Here we propose to explore the nature of these potential ‘nanoparticles’ (herein referred to as nanoparticles) in order to shed some light on their role in the carbon sequestration process.  Currently, we do not understand how we have ‘nanoparticulate’ Mn oxides at all in the peaty water, as the water is high in organic matter which would conventionally be thought to provide reducing conditions which would reductively dissolve all manganese oxides.  Therefore we would like to use FENAC facilities in order to a) characterise the natural nanoparticulate Mn oxides in both the influent peaty water and the nanoparticulate fraction from the filter bed in the WTW and b) synthesise nanoparticulate manganese oxide which do not contain any organic matter and compare it with the natural nanoparticulate Mn oxides. 

Oceans of plastic:  Screening for plastic nanoparticles in a marine ecosystem

James Reynolds

Marine ecosystems are under threat from over-exploitation, habitat degradation, climate change and pollution.  Plastics are major pollutants of all oceans where they have impacts on seabirds.  The focus of this project is the Sooty Tern (Onychoprion fuscatus) that is an important bio-indicator of marine health on Ascension Island in the South Atlantic.  We will develop methods to detect nanoplastics in Domestic Fowl (Gallus domesticus) tissues and fish samples, and then characterise nanoplastics in Sooty Tern blood, eggs and their fish prey.  This will allow subsequent work to examine the prevalence and fates of nanoplastics in marine food chains. 

Involvement of nanoscale vesicles in food spoilage by mucormycete fungi

Kerstin Voelz

Germination of mucormycete fungi causes spoilage in a range of crop species.  Preliminary data suggests that the onset of hyphal^a formation is preceded by the release of nano-scale extracellular vesicles^b by the fungal spores.  This pilot application seeks to visualise vesicle production by fungal spores using electron microscopy techniques and quantify their release into the environment using NTA.  Further, the application seeks to characterise the physical nature of the vesicles (hydrodynamic diameter / surface charge) in order to better predict their dissemination through their immediate environment and give clues to their likely role in the process of fungal germination. 

SOS-Nano Structure – Oxidative Stress relationships of metal oxide nanoparticles in the aquatic environment

Tamara Galloway

The SOS-Nano project addresses a pressing issue of econanotoxicology at present:  the need to identify structural property of nanoparticles (NPs) that may be used to predict their potential toxicity in natural aquatic environments, the final sink of released NPs.  By using an in vitro –exposure system using natural water, SOS-Nano tests the suitability of two paradigms recently demonstrated to be effective in vitro for ranking the hazard of metal oxide NPs:  1) NPs physical-electrochemical properties for predicting oxidative stress potential, and 2) oxidative stress generation for predicting biological impact.

The experimental plan of SOS-Nano is totally innovative in design and methodology:  the relationships between NPs structure and toxic activity is studied under the influence of natural water properties, and the toxic potential is ranked through a multi-tier system combining genomics and functional measurements. 

Sulphidised nanoparticle characterisation for long-term soil solubility studies

Stephen Lofts

Sulphidisation of zine oxide and silver nanoparticles is known to occur prior to their environmental release as contaminants of biosolids from wastewater treatment applied to agricultural land.  However, little is known about the long term (annual/decadal) behaviour of such particles (in particular the potential for slow release of metal due to solubilisation) and the consequent environmental risks.  The proposed experimental work will study the solubility of sulphidised forms of these nanoparticles in soils on an annual basis for up to a decade.  Sulphidised particles will be synthesised from as-manufactured zine oxide and silver nanoparticles before spiking into a series of soil mesocosms and periodic analysis of solubility by porewater sampling.  Robust characterisation of the chemical and mineral composition, and size distributions, of the sulphidised particles is required to interpret their subsequent solubility behaviour.  The results will inform policy on the application of biosolids containing nanoparticles to land on the basis of long term particle persistence and solubility. 

Assessing ZnS nanoparticle behaviour in UK soils

Andrew Tye

The experiment will investigate the fate of ZnS nanoparticles (NPs) in 10 different soils using environmentally realistic concentrations (20 mg kg^-1) over 100 days.  Results will be compared to similar applications of ionic and bulk ZnS particles to examine size-dependent effects.  A combined approach will be used involving solution analysis using FIFFF and SP-ICP-MS to examine changes in NP size distribution and a modified E-value assay to examine changes in the labile Zn pool.  Using labelled ⁶⁸Zn particles will allow mass balances to be calculated of native and NP zinc.  Results will benefit regulators determining appropriate biosolid applications to soils. 

Characterisation of engineered nanoparticle impacted sewage waters

Alexandra Porter

The objective of the research project is to quantify the lifetime and to characterise the physiochemical characteristics of engineered nanomaterials (ENMs) as they reach the environment through wastewater treatment plants (WWTP), specifically as they partition between 1) water, wastewater, sludge and soil and 2) effluent and freshwater.  The ENMs of interest are CeO_2, ZnO, TiO₂ and Ag. 

Quantifying the role of nanoparticles in fluvial metal flux in mining-impacted catchments

Patrick Byrne

Mine wastes represent the most significant source of potentially toxic metals worldwide.  Fluvial transport is the primary mechanism by which these metals (e.g. Pb, Zn) are transported through the environment.  A large proportion of fluvial metal flux is thought to be associated with sub-micron particles and to occur during storm-induced high river flows.  However, the relative contribution of nanoparticles to fluvial metal flux remains unknown.  This knowledge gap currently limits our process-based understanding of metal contaminant dynamics and eco-toxicity in fluvial systems.  The purpose of this work is to quantify, for the first time, nanoparticle metal flux during storm events.

Analytical methods for the detection of nanoparticulate zero valent iron (nZVI) in the environment

Katherine B Holt, University College London

Nanoparticulate Zero Valent Iron (nZVI) has proposed uses in the remediation of contaminated land. However to assess the risk of their use in this application there is an urgent need to develop new analytical methods for the detection and tracking of nZVI (and other metal nanoparticles) in the environment. This project seeks to assess the viability of electrochemical methodologies for this application and to benchmark electrochemical approaches against other analytical techniques available at FENAC. 

Imaging the evolution of Ceria nanoparticles in sediment pore waters over time

Tamara Galloway, University of Exeter

Sediments are predicted to be a major environmental sink for engineered nanoparticles. The fate of these nanoparticles in sediments will be dominated by dynamic transformations, which will alter the nanoparticles shape, size and coatings. As the toxic potential of these nanoparticles to organisms will depend upon their uptake and bioaccumulation, it is vital to understand how these dynamic transformations within sediment will affect nanoparticle availability to sediment dwelling species. Our aim is to use the imaging facilities at FENAC to characterise the change in Ceria nanoparticle size, their associations with natural colloids and how these transformations develop over time. 

Uranium (IV) silicate colloids in alkaline conditions

Samuel Shaw, University of Manchester

Uranium(IV) colloids have the potential to greatly enhance the mobility of uranium in anaerobic systems, including contaminated land, geodisposal environments and radioactive waste storage facilities. Recent studies have shown that the presence of silicate has the potential to stabilise U(IV) in a colloidal form (primary particle size < 20nm). However, the chemical and physical (e.g. size and surface charge) properties, and longer term (months/years) stability of these colloids under relevant chemical conditions are poorly understood. Here we propose to use Zeta Potential, Nanoparticle Tracking Analysis (NTA) and Dynamic Light Scattering (DLS) to characterise these U(IV) silicate colloids. 

TEM of nanoparticles in Caco-2 cells

Susan Fairweather-Tait, University of East Anglia

Iron deficiency is the most prevalent nutritional deficiency in the world. Nanoparticles, both natural forms found in foods (ferritin)^1,2 and synthesized forms (ferric phosphates, iron oxides)^3,4 are currently being examined by various groups as a potential form of bioavailable (well absorbed) iron. They speculate that these iron nanoparticles are absorbed via a unique endocytic process. Our group has currently purified ferritin from peas (P.sativum) and also have been kindly donated ferric phosphate nanoparticles. We hope to confirm the process of endocytosis of iron nanoparticles by imaging and visualising its uptake into a well-characterised cell model using TEM.  

Development of a novel biomarker of exposure to iron nanoparticles in urine and exhaled breath condensate samples using single particle inductively coupled plasma mass spectrometry

Juana Maria Delgado-Saborit, University of Birmingham

In recent years, nanotechnology research and product development has increased exponentially due to new and beneficial properties of nanoparticles (NPs). However, non-engineered NPs incidentally released to the atmosphere as a by-product process (e.g. combustion, welding) are also commonly found in the environment. Results of the FABLE project have shown that Fe NPs are very common in outdoor air, being likely associated with brakes and vehicle engine exhaust. Therefore, human exposure to NPs in both occupational and ambient environments might be widespread. However, the lack of information on human exposures and health effects associated to NP exposure alongside recent results from animal toxicological studies has raised regulatory concerns regarding the health of occupationally exposed workers to NPs. Tools to characterise exposure to (Fe) NPs and define preventive measures for workers are necessary to assure adequate occupational health and safety standards. Likewise, epidemiological studies could benefit from markers characteristic of internal exposure to (Fe) NPs that could be linked with possible toxicological and health effects.

Biological markers might play a key role in characterising the internal dose representative of the exposure to (Fe) NPs. Single particle ICPMS analysis, which is a technique available at the FENAC facility, offers the possibility of measuring concentration and size of individual NPs in aqueous biological samples, such as urine and exhaled breath condensate (EBC). It also offers the opportunity to differentiate between the internal dose associated with dissolved metals and the dose of metallic NPs. This will be of utmost importance to understand if biological effects are associated to the dissolved metal or to metallic NPs. This proposal aims at developing and implementing the first analytical method that would allow the analysis of Fe NPs in EBC and urine as biomarkers of exposure to metallic iron NPs that would allow the characterisation of internal doses to Fe NPs. It aims also to assess the relationship between exposure to Fe NPs and early health effects of inflammation and oxidative stress, biomarkers which have been also collected as part of the FABLE project. Other expected outcome of this research is to establish a reference range of typical concentrations of Fe NPs in urine and EBC that will be useful to assess exposures in the general population in subsequent studies. 

Determining Dynamic Nanoparticle Uptake On Subcellular Scale Using Correlative light Electron Microscopy

Kenton Arkill, University of Nottingham

There are several ways to determine cellular internalisation of nanoparticles. Optical imaging has an adequate spatial resolution and has dynamic capabilities. Electron microscopy is used as it has, in standard plastic sections, a resolution in the low nanometre range, but more importantly the particles can be observed within the cellular substructures. This is a method development proposal, aiming to combine these techniques on the same sample using Correlative Light and Electron Microscopy (CLEM). The aim of this proposal is to demonstrate the applicability and potential of the CLEM method to environmental nanoscience using Pseudomonas Putida as a subject.

Behaviour and fate of nanoparticles in wastewater treatment works

John Bridgeman, University of Birmingham

We propose to undertake the first study on the quantification and characterisation of nanoparticles through the main wastewater treatment processes, from crude to final effluent. No research has been undertaken, so far, to assess the removal efficiency of nanoparticles along the wastewater treatment process train.  Such analyses will provide valuable insights into the fate and behaviour of nanoparticles through individual treatment stages. The knowledge arising from this research will facilitate minimisation of energy usage during wastewater treatment and a reduction of the ecological impact on the effluent receiving water bodies. 

Colloidal organic matter in an urban river: novel insights into storm flow dynamics and trace metal transport using flow field-flow fractionation 

Chris Bradley, University of Birmingham 

To-date mobilization and transport of organic matter (OM) in urban rivers has been poorly characterized during storm events, despite the strong coupling between OM composition and water quality (i.e. oxygen demand/trace metal fate). In particular, our understanding of variations in the composition, size distribution and metal binding potential of colloidal organic matter (COM) is limited. Here we propose a novel study to explore the intra-event dynamics of COM in an urban river using field-flow fractionation. This seeks to relate OM mobilization and transport to key water flow pathways (sewer discharge; road runoff) that will vary during flow events. 

Natural nanoparticles in soils and their role in nutrient cycling – probing interactions of nano Fe oxides with P in tropical soils 

Agnieszka Dybowska, Natural History Museum

Nanoparticles are ubiquitous in the soil environment. Advances in separation techniques, analytical, imaging and spectroscopic techniques make it now possible to study such natural nanoparticles; however we have limited knowledge of their chemical, structural and morphological identity and reactivity, in particular in complex matrixes such as soils. This is in spite of the fact that natural nanoparticles most likely play a key role in important processes such as soil genesis, contaminant and nutrient transport/immobilization. Here we investigate the role of soil nanoparticles (in particular nano-sized crystalline Fe oxides) in P retention in Oxisols from Brazil and implications of this process on P availability in these soils. Highly weathered, acidic soils from the Cerrado region of Brazil are rich in nano-sized goethite (α-FeOOH) and hematite (Fe₂O₃) – two of the most common crystal forms of Fe oxides in soils. These occur mainly as aggregates of individual particles, often smaller than 10nm and with varied morphology. We will study, in particular, the effect of particle size, morphology and crystal phase of Fe oxides on P sorption. Phosphorus association with Fe will be probed using high resolution imaging and analysis techniques namely HRTEM coupled with EDX and EELS. These techniques will provide the first direct evidence of P-Fe association in soils at the nanoscale. 

Investigating the aggregate size distribution of Ceria nanoparticles within sediment and tissue samples 

Tamara Galloway, University of Exeter 

This project will investigate the size distribution of aggregated CeO₂and any natural bound colloids within freshwater sediments. This will provide essential complementary data on the uptake of CeO₂nanoparticles by the freshwater oligochaete Lumbriculus variegatusto examine the link between transformations to the nanoparticles within sediments and their impact upon uptake in organisms. The use of FlFFF allows environmentally realistic size distributions of CeO₂ to be characterised within the complex sediment media used for exposures. This will contribute both to the specific aims of a doctorate project and to our wider understanding of the partitioning and transformations which engineered nanoparticles undergo within complex sediment environments.

Characterisation of the protein corona formed on carbon nanomaterials exposed to human lung lining liquid 

Dr Andrew Thorley, Imperial College London

Carbon nanomaterials have created great excitement as they possess unique characteristics which make them ideal for development of novel theranostics, drug delivery vectors and lightweight, flexible electronics. Consequently, there is a significant likelihood of both deliberate and passive exposure to these materials. One primary route of exposure is via inhalation. Inhaled nanomaterials preferentially deposit in the deep lung where they will interact with the protective surfactant layer that coats the lung lining; this may have adverse health effects. This study will elucidate which proteins in this surfactant layer bind to carbon nanomaterials in relation to the physicochemical properties of the material. 

Testing nanoparticle physicochemistry to validate the Nanoparticle Standardized Chamber for Aqueous Phase Ecotoxicology (Nano-SCAPE) test 

Theodore Henry, Heriot-Watt University 

Investigating NP ecotoxicity requires preparation of reproducible homogeneous exposure conditions.  We have designed a standardized chamber that maintains homogenous aqueous phase dispersions of metal NPs [total metals concentrations maintained over 96 hours (a typical exposure duration for fish early life stage ecotoxicity tests)], and have demonstrated reproducible results of NP toxicity in larval zebrafish.  We call the system Nano-SCAPE.  We propose to use FENAC to characterize physicochemistry of selected NPs in the Nano-SCAPE system under operational conditions.  Our objective is to evaluate whether physicochemistry of four particles (Au-NP, Ag-NP, TiO₂-NP, and nanoplastic) changes over 96 hours.

Development of a Novel Screening Approach for the Hazard Assessment of Nanoparticles using Both Cell Line Panel and Whole Embryo Analysis

Francesca Baldelli Bombelli, UEA 

With the advancement of nanotechnology for a widening spectrum of potential applications it comes an ever increasing risk of unintentional contact with these particles and the associated health and environmental risks of any related exposure. The aim of this proposed project is to develop a toxicity assessment protocol that is suitable for determining the hazard potential of a range of nanoparticle types. All the systems we shall use have the potential to be scaled up for high-throughput assessment that can be utilised for industrial scale toxicity testing in the future. Our overall aim for this project is to develop a standardised protocol for the hazard assessment of nanoparticles.

Nanoparticles and their protein corona 

Jens Madsen, University of Southampton 

When nanoparticles (NPs) enter a biological fluid, proteins associate with NPs leading to a protein "corona" that largely defines the biological identity of the particle.  The aim of the research project is to perform a physico-chemical characterisation of the protein corona formed on a variety of different NPs incubated with lung lavage or isolated human lung cells as a model for NP exposure via the lungs (air pollution). This characterisation is a part of a PhD studentship to understand how the exposure route affects the biological identity of NPs and if this interaction affects the cells subsequent response to infection.

Ecologically relevant nanoparticle coronas and  how they influence the particles’ fate and behaviour in artificial and natural freshwater systems

Daniel Read, CEH (NERC), Wallingford

This project investigates the development of eco-coronas for silver nanoparticles (AgNPs) formed from polymeric substances exuded by microbes (naturally and as a stress reaction). Eco-coronas resulting from interactions between AgNPs and microbial organisms may change the particles properties (e.g. dissolution, agglomeration, surface charge & coating) and their bioavailability (uptake & toxicity). Uptake and localisation will be assessed using TEM (and potentially ESEM) imaging of the NP-exposed organisms, and correlated with uptake and 3D imaging using confocal microscopy. The project results will provide major advance on NP-microbes interactions and help explain current mainly observational NP toxicity studies on bacteria and algae.

Uptake and localization of different silver nanoparticles in nematode tissue and potential formation of eco-coronas in an environmentally relevant exposure medium     

Claus Svendsen, CEH, Wallingford

This study aims to investigate the fate of silver nanoparticles (AgNPs) with varying properties such as size, surface coating and surface charge and their toxicokinetics in the nematode Caenorhabditis elegans. C. eleganshave been shown to assimilate AgNP, however, little is known about actual routes of uptake and distribution within the organism and particle dependent differences thereof, which we will investigate using TEM and confocal microscopy. Furthermore, we propose to study eco-coronas formed around ingested AgNP and aim to fully relate potential differences in impacts of the various AgNPs to routes of uptake and distribution. 

Nanomaterial fate, transport, behaviour and bioavailability in the environment               

Teresa Fernandes, Herriot-Watt University

This research aims to assess silver nanoparticle (NP) dynamics (dissolution and aggregation/agglomeration behaviour) under variable water chemistry and fluid flow/turbulence rates in order to explore the environmental fate and behaviour of NPs in the environment. Specifically this project will address:

1. How water chemistry and NP surface modifications may affect the behaviour of silver NP;
2. How environmentally related factors e.g. pH, sunlight and flow rates/turbulence* may affect silver NP aggregation and dissolution

*flow/turbulence will be generated in a flume, which is designed to be portable and representative of natural systems. This project is undertaken in collaboration with School of Built Environment at Heriot-Watt University where the flume work will take place. 

Characterisation of nanometre-sized aluminium sulphates:  implications for mobility of aluminium from mine wastes     

Karen Hudson-Edwards, University of London 

Wastes produced from the mining and extraction of metal, industrial mineral and energy resources constitute one of the largest waste streams on Earth, and they can contain considerable quantities of potentially toxic elements. Aluminium (Al) is one of these elements, whose high concentrations can have severe effects on ecosystems and

humans. The risks posed by exposure to Al are controlled by the reactivity of Al-bearing minerals, which in mine wastes are most commonly the sulphates alunite [KAl₃(SO₄)₂(OH)₆] and basaluminite [Al₄(OH)₁₀(SO₄)⋅4H₂O]. In spite of their importance, the rates, mechanisms, products and controls on the dissolution of these Al sulphate minerals in mine waste environments are not well known. Part of the reason their reactivities are poorly understood is likely that they occur as nano-sized particles, which have been poorly studied. In order to bridge this knowledge gap, dissolution experiments using both natural and synthetic alunite and basaluminite are being carried out. Since particle size has been shown to be one of the main controlling factors for the dissolution of minerals, and because nano-sized sulphates occur in the natural environment, it is of paramount importance to conduct the experimental work using both nano- and micro-sized alunite and basaluminite. Before we can conduct these dissolution experiments, however, we need to synthesise and characterise nano-sized alunite and basaluminite, and compare and contrast their properties to their micro-sized equivalents. We are applying to FENAC for the facilities and expertise to carry out this research. 

Probing surface hydrophobicity of non-biodegradable, polymeric nanoparticles by AFM

Marie-Christine Jones, University of Birmingham

This pilot project will concentrate on the feasibility of using atomic force microscopy (AFM) to evaluate nanoparticle surface hydrophobicity. Despite being recognised as an important factor for interactions with bio- and ecological systems, surface hydrophobicity is not routinely explored as part of standard nanoparticle characterisation. Here, it is hypothesised that measuring adhesion forces between chemically modified AFM tips and nanoparticles can be used to measure hydrophobicity. Experiments will be conducted on two separate polymeric nanomaterials with known discrepancies in terms of surface properties with the aim to address potential experimental caveats. 

Are iron nanoparticles in wet deposition a potential source of bioavailable Fe to marine algae?

Zongbo Shi, University of Birmingham 

The iron (Fe) biogeochemical cycle has a critical influence on primary production in large areas of the oceans, and consequently has the potential to impact on climatic change through the fixation of atmospheric carbon by phytoplankton. Iron nanoparticles (FeNPs) are known to occur in rainwater (Shi et al., 2009) as a result of atmospheric processing of mineral dusts, and thus are a potential source of bioavailable Fe in high nitrogen, low carbon (HNLC) areas of the ocean through wet-deposition.  This project will investigate the extent to which Fe (ferrihydrite) nanoparticles are bioavailable to a model marine diatom Thalassiosira pseudonana. 

The project plan adopts a tiered approach using progressively more environmentally relevant forms of FeNP: 

• Laboratory synthesised FeNPs with PVP and humic acid capping agents.
• FeNPs generated from simulated atmospheric processing of mineral dust.
• FeNPs from natural rainwater. 

This tiered approach will allow characterisation methods to be optimised with relatively well-defined NPs, prior to characterising less abundant, and less well studied environmentally derived NPs. 

Reference

Shi, Z. B.; Krom, M. D.; Bonneville, S.; Baker, A. R.; Jickells, T. D.; Benning, L. G., Formation of Iron Nanoparticles and Increase in Iron Reactivity in Mineral Dust during Simulated Cloud Processing. Environmental Science & Technology 2009,43(17), 6592-6596. 

Synthesis and characterisation of isotopically labelled labelled Fe oxyhydroxide nanoparticles

Eniko Kadar, Plymouth Marine Laboratory

Atmospheric iron deposition in the form of mineral dust and volcanic ash increases phytoplankton productivity in iron-limited areas of the ocean, with major potential implications on the Earth’s carbon cycle. Despite that, the environmental fate of Fe-rich natural nanoparticles (NPs) derived from atmospheric dust/ash deposition is very poorly understood, partly as these particles are nanosized and technologies for their detection/quantification are only beginning to be available. Based on our recent laboratory simulations [1, 2] we hypothesize that Fe-rich natural nanoparticles (NPs) in the form of oxy-ferrihydrites are chief portion of the bioavailable iron following atmospheric dust/ash deposition, but we do not have accurate figures on the conversion of various types of parental dusts into nanoparticulate material or on which forms of nanoparticulate iron are prevalent upon contact with seawater. We also need a better understanding on how marine organisms might take up and utilise nano forms of Fe.

Here we seek funds to synthesise stable isotopically labelled ferrihydrite nanoparticles (via simulated cloud processing) to be used as model nanoparticles in both cloud processing simulations and microalgal exposure studies in order to fill the knowledge gaps on the biological uptake and consequences of atmospheric dust deposition.

References

Kadar, E.; Fisher, A.; Stolpe, B.; Calabrese, S.; Lead, J.; Valsami-Jones, E.; Shi, Z., Colloidal stability of nanoparticles derived from simulated cloud-processed mineral dusts. Sci. Total Environ. 2014,466, 864-870.

Kadar, E.; Cunliffe, M.; Fisher, A.; Stolpe, B.; Lead, J.; Shi, Z., Chemical interaction of atmospheric mineral dust-derived nanoparticles with natural seawater - EPS and sunlight-mediated changes. Sci. Total Environ. 2014,468, 265-271.

Biological uptake and effects of metal oxide nanomaterials in early life stages of fish and for exposure to a complex mixture        

Charles Tyler, University of Exeter

A series of hypotheses will be tested relating to the potential bioavailability and effects of metal oxide nanomaterials in early (potentially vulnerable) life stage fish and for uptake into fish for an aqueous complex mixture. The experiments will provide much needed data on the potential for metal oxide NPs to induce harm in exposed organisms as well as further developing new in vivoexperimental systems for nanotoxicology research. We require access to the FENAC facility for characterisation on the particles raw and in their exposure matrices and (more extensively) to assess tissue targets and burdens in exposed animals to support biological effects outcomes

Transfer of Bulk and Nanoparticulate Cerium between a Mussel and a Crab

Tamara Galloway, University of Exeter

Cerium oxide nanoparticles have many industrial and commercial uses, and there is high potential for them to reach the aquatic environment and ultimately enter the marine food web.  This project will investigate the bioavailability of bulk and nanoparticle cerium oxide and the potential for trophic transfer in a simple marine food web involving the mussel Mytilus edulis(filter feeder) and the shore crab Carcinus maenas (omnivorous scavenger).The results will provide fundamental knowledge of the ways in which manufactured nanomaterials interact with ecological vectors under environmentally realistic conditions and aid in the development of appropriate ecotoxicology testing systems to safeguard the environment.

Characterization of a commercial product containing silver nanoparticles (AgNPs) and pristine AgNPs in relevant estuarine conditions  

Mark Hartl, Herriott-Watt University

The toxicity of AgNPs depends on their physicochemical characteristics, their interactions with the environment  in  which  they  have  been  released  and  any organism  exposed to them.  In the present study, the antibacterial properties of three different AgNPs are explored. It is fundamental to characterize these NPs in relevant media when the exposure begins, during the course of  the  experiment and at  the  end of  it. The clarification of these aspects is essential for meaningful environmental risk assessment and regulation of an emerging technology. Investigating the influence of salinity on AgNPs is essential to evaluate their effects in estuarine ecosystems.

This project aims to conduct fundamental research into the fate and transport behaviour of silver n.anoparticles (AgNP) in wastewater treatment plants (WWTP). Laboratory column and reactor studies will be carried out to evaluate the interactions between AgNP and primary, secondary and tertiary treatment processes including activated carbon,trickling filters,biofilms and sand filters amongst others. Analysis will include a range of system conditions such as AgNP influent concentrations, substrate type, water hardness, temperature, pH, presence of ligands and nanoparticle coatings. Access to the FENAC facilities is required for the quantification and characterisation of the AgNP before and after passage through the experimental systems to inform on their nature, how they may be modified and for effluent characterization. 

Synthesis and Characterization of isotopically labelled ¹⁴⁰CeO₂ nanoparticles

Mark Rehkamper, Imperial College London 

Recent work, carried out in the group of PI Rehkämper in collaboration with other researchers, has shown that the technique of stable isotope labelling is an extremely powerful and sensitive tool for the tracing ZnO nanoparticles in complex systems. Modelling and pilot analyses indicate that stable isotope labelling should be similarly effective for tracing CeO2 nanoparticles, offering detection sensitivities that surpass conventional methods, which are based on Ce concentrations measurements, by several orders of magnitude. 

Hence, we here seek funds to carry out the first synthesis of isotopically labelled 140CeO2 nanoparticles. Following preparation, the particles will be characterized to ascertain that the physico-chemical properties of labelled and non-labelled particle forms are essentially identical. 

Characterising silver nanoparticle stability in suboxic waters

Dan Lapworth, British Geological Survey

This study will characterise the changes in physical and chemical characteristics of capped and uncapped AgNP within synthetic sub-oxic aqueous matrices following exposure to S2-, and in the presence/absence of humic-like material. The stability of a range of capped AgNPs (e.g. citrate, PVP, PEG) will be included in the study. The stability of AgNPs due to the formation of Ag-sulphide and Ag- organic matter interactions will be evaluated and tested. In parallel with this study analysis of AgNP and humic acid mixtures using SANS will be carried out to monitor the changes in particle size distribution in experimental mixtures in-situ.

Impact of engineered nanoparticles on aquatic microorganisms and their processes

Prof. I. Colbeck; University of Essex

This project investigates the effect of engineered nanoparticles (e.g. silver, titanium dioxide and carbon nanotubes) on the community structure and activity of aquatic microorganisms that biodegrade hydrocarbon pollutants and those responsible for nitrification. Analytical techniques will be used to measure rates of hydrocarbon-degradation and nitrification, while molecular techniques will identify and quantify shifts in the in situmicrobial community structure in the presence of different nanoparticle species. TEM imaging will be used to investigate interactions between nanoparticles and bacterial cells. Results from this project will provide a major advance on how nanoparticles interact with key microbial processes in aquatic ecosystems.

Characterization of isotopically labelled ¹⁰⁹Ag nanoparticles

M. Rehkämper; Imperial College London

Preliminary analytical studies conducted at Imperial College have shown that the technique of stable isotope labelling should enable extremely high sensitivities for the detection of Ag nanoparticles in bulk natural samples. Hence, we will prepare isotopically labelled  ¹⁰⁹Ag nanoparticles for subsequent pilot studies that investigate toxicology and environmental fate. Here, we seek funds that will allow us to use the FENAC facilities to characterise such  ¹⁰⁹Ag nanoparticles for key physico-chemical properties in various aqueous media that are relevant for toxicological and environmental studies. Additional analyses will be carried out for conventional Ag nanoparticles, to confirm that labelled and unlabelled Ag nanomaterials display identical behaviour. 

Cellular handling of synthetic and natural (mineral dust- and volcanic ash-derived) iron-rich NPs and their influence on the growth of marine microalgae

Dr. E. Kadar; Plymouth Marine Laboratory

It is well established that Fe availability controls phytoplankton productivity, community structure, and ecosystem functioning in vast regions of the global ocean (approx. 30%). While we have demonstrated in our previous project (FENAC/2010/05/006) that nanoparticles are derived from iron-rich mineral dusts/volcanic ash via cloud processing, the consequently improved bioavailability of the particles needs further in depth investigations. Here we propose culturing algae with distinct Fe handling strategies at the laboratory scale using nano-iron amended media. In doing so we will test the hypothesis that natural, Fe-rich NPs from cloud processed mineral dusts (CPMD) are more bioavailable than the bulk analogue. We will thus be able to make predictions on the larger scale implications of dust deposition on ocean productivity and potential effect on changing climate. 

Characterisation of marine colloids and nano particles associated with metals

Dr. M. Gledhill; National Oceanography Centre Southampton

Shelf sediments represent an important supply of iron to open ocean waters. The supply of iron from shelf sources involves long range transport of iron in seawater, which requires stabilisation of iron in order to prevent loss by scavenging. The physico – chemical form of iron within the water column is critical to stabilisation. We propose to investigate the nature of soluble, colloidal and particulate iron released from shelf sediments and thereby assess the importance of different iron fractions to offshore iron transport. We will use FENAC to characterise particulate and colloidal iron released from the shelf sediments.

Nanoparticles of Hydroxyapatite are Templated onto Serratia sp. and Form Particles with Increased Metal Remediation Capacity

Prof. L. Macaskie; University of Birmingham

Biomineral hydroxyapatite (Bio-HAp) produced by Serratia sp. could be a suitable material for the remediation of heavy metals from waters and as a nuclear waste storage material. Bio-HAP is up to 10 times more efficient at aqueous metal removal than commercially available hydroxyapatite [1]. However, Bio-HAP contains up to 50% organics which can degrade, releasing heavy metals back into the environment [2]. Once normalized for surface area, a significant relationship between Bio-HAP crystallite size and metal uptake has been observed. This proposal aims to understand the mechanism of Bio-HAp formation and growth so that this unique material can be synthesised in laboratories.

Nanoparticles and their impact on the bioremediation of hydrocarbons in aquatic ecosystems

Ian Colbeck, University of Essex

This project will investigate the effect of different nanoparticle species (e.g. silver (capped and uncapped), carbon nanotubes and titanium dioxide) on the community structure and activity of microorganisms that actively metabolise specific hydrocarbon pollutants in marine and freshwater environments. Molecular techniques will identify and quantify shifts in the in situmicrobial community structure and activity in the presence of different nanoparticles, and this information will be correlated (via analytical methods) to the physical and chemical characteristics of the nanoparticles (e.g. size, species, surface properties etc) and rates of hydrocarbon-degradation. This will provide important information on how nanoparticles affect the microbial interactions involved in hydrocarbon-degradation in aquatic environments, and is a major advance on how nanoparticles interact with key microbial processes in marine/freshwater ecosystems.

The ecotoxicology of zinc oxide and silver nanoparticles with respect to aquatic sediment dwellers

Prof. V. Stoneand Prof. T. Fernandes, Heriot-Watt University Edinburgh

This study aims to investigate the effects of engineered ZnO and Ag nanoparticles in aquatic sediment dwellers. Lumbriculus variegatus is a fresh water oligochaete, found throughout North America and Europe. Due to their feeding behaviour, Lumbriculus variegatusmake excellent test organisms for studying the bioaccumulation of contaminants. Nereis diversicoloris a marine polychaete worm found throughout Europe and the North American Atlantic coast whichhas been extensively used as a biological models it can tolerate a wide range of salinities and pH. Benthic-dwelling organisms are ideally suited for the assessment of any effects of nanomaterials given their propensity to settle when in aquatic environments. The effects of the selected nanoparticles will be assessed via a number of endpoints, e.g. behaviour, mortality, reproduction, histology and biochemical assays, with and without the addition of humic acid.

Advanced fish model systems for understanding biological effects of metal oxide nanomaterials

Prof. C. Tyler; University of Exeter

In this project we propose three integrated studies developing the use of fish models to assess the potential health effects of metal/metal oxide nanoparticles (NPs): 1.) exploring the sensitivity of zebra fish embryos to NPs via the application of whole mount in situhybridisation with selected gene targets, 2.) assessing NPs effects at the level of the whole genome (using digital transcriptomics on tissues that accumulate NPs), and 3.) exploring a new fish model (Xenotoca eiseni) for studying maternal –offspring transfer of NPs. We require access to the FENAC facility to complete a comprehensive characterisation on the particles raw and in their exposure matrices and to assess tissue burdens in exposed animals.

Characterisation of natural nanoparticles in fumarolic gas/fluids from Ischia and Vulcano (southern Italy)

Dr. E. Kadar; Plymouth Marine Laboratory

The fumaroles within the geothermal field on the islands of Ischia and Vulcano (southern Italy) have recently been in the spotlight providing natural laboratory conditions to study adaptations to ocean acidification i.e. valuable predictors of future ocean ecology owing to their elevated CO₂flux. Moreover, steep pH gradients combined with metal enriched fluid emissions typical at hydrothermal vents (Kadar et al., 2005) are in fact conditions known to facilitate formation of iron rich nanoparticles (NPs) (Kennedy et al., 2004). The actual morphology, mineralogy and chemical properties of the NPs emitted in hydrothermal fluids are virtually unknown because analytical techniques for NP characterisation were not available until recently. We propose to investigate metal-rich and organic nanoparticles from various volcanic fluids and/or gas along a natural pH gradient (Hall-Spencer et al., 2008) as part of a larger scale horizon scanning study to search for and characterise new naturally occurring nanoparticles. This would give us clues to answer to the fundamental nanoscience question: are biological feedbacks to naturally present NPs inherently different from those in response to engineered NPs?

Removal of Radionuclides into Biogenic Hydroxyapatite: Implications for Nanoparticulate Biomineral Remediation Technology

Dr. J. Renshaw; University of Birmingham

Detailed bio-synthesis and sorption experiments supported by FENAC showed that Biological Hydroxyapatite (Bio-HAp) is superior to commercial hydroxyapatite for the remediation of aqueous radionuclides. Studies showed thatSerratiasp. produces nanoparticulate Bio-HAp with properties that increase metal uptake (i.e. smaller crystallite size of <40 nm and higher surface area of >70 m²g^-1). Gradual sintering will slowly change Bio-HAp properties and subsequently affect metal uptake. Evidence from this study will help determine the most stable and appropriate forms of Bio-HAp for nuclear waste remediation and will compliment synchrotron X-ray absorption spectroscopy time which aims to elucidate modes of metal incorporation .

Ecotoxicology of metal oxide nanoparticles in a sediment dwelling invertebrate

Prof. T. Galloway; University of Exeter

This project will investigate the bioaccumulation and biological effects of zinc oxide nanoparticles (ZnO NPs) in a sediment dwelling invertebrate. ZnO NPs are widely used in sunscreens and cosmetics. The amphipod Corophium volutator(mud shrimp) is an OECD model species and constituent of the marine food web. Here, we will combine isotope tracing methods with high detection sensitivities, physico-chemical and bio-imaging techniques, to provide a comprehensive analysis of the effects to C. volutatorof ZnO NPs, compared with ZnO in bulk and soluble forms. The study will offer insight into the normal physiological processes used to detoxify metal oxides in vivo.

Ecotoxicology of cerium oxide nanoparticles in aquatic invertebrates

Prof. T. Galloway; University of Exeter

This project will investigate the sub lethal biological effects of cerium oxide nanoparticles (CeO₂NPs) in an aquatic invertebrate species. CeO₂NPs are widely used as fuel additives and polishing agents. The amphipod Corophium volutator(mud shrimp) is an OECD model species and constituent of the marine food web. Here, we will explore the uptake and biological effects of CeO₂NPs in the gut and storage tissues, with a focus on oxidative damage. The results of this study will aid in determining the risks associated with environmentally relevant exposures to CeO₂NPs.

Nanoparticles and atherothrombosis: resolving the paradox

N. Mills, University of Edinburgh

Exposure to ambient ultrafine particles has been associated with adverse cardiovascular events. Combustion-derived nanoparticles are thought to be the main mediators of these effects. We will attempt to establish the properties of nanoparticles which are most likely to elicit a prothrombotic effect and determine whether pulmonary exposure to nanoparticles can lead to extrapumonary distribution and contribute to cardiovascular disease. We will take a systematic approach and endeavour to relate nanoparticle toxicity to physiochemical structure, with the hope of developing a QSAR model, which would be applicable to many different types of nanoparticles, from many sources thus aiding in the design of safer nanoparticles for medical purposes and in establishing safe limits of exposure in occupational and environmental settings.

Nanoparticles and their impact on the bioremediation of hydrocarbons in aquatic ecosystems

Ian Colbeck, University of Essex

The main aim of the project is to investigate the effects nanoparticles (carbon nanotubes, silver nanoparticles and titanium oxide nanoparticles) on the breakdown of crude-oil hydrocarbons by marine and freshwater hydrocarbonoclastic microbial communities. Further work will later focus on the impact of nanoparticles on other integral processes carried out by indigenous marine microbial populations, such as methane oxidation, nitrification and denitrification. Whilst the microbiological techniques are readily available within the Department a wide range of physical and analytical detection methods are also required to understand how structure and chemistry can influence the environmental function of nanoparticles.

Lung surfactant polymer interactions with nanoparticles

M. Kendall, University of Southampton  

Clark and Kendall proposed a novel hypothesis that lung surfactant polymers have a role in inflammation of the lung resulting from nanoparticle (NP) exposure. One completed NERC project (Kendall et al 2009) and a MRC project have begun to elucidate the protective role of lung polymers in the toxicology of nanoparticles (Kendall 2009, Submitted to Nanotoxicology). Here we propose a NP characterisation project to support these important studies. The project will characterise NP surfaces and aggregation behaviour in interaction with the molecules of interest. The project is a unique collaboration of cross-faculty members and a fledgling PhD project.

Nanoparticle characterisation in floodplain and wetland environments

D. Lapworth, British Geological Survey

Groundwater is an important natural resource, providing drinking water and sustaining rivers and wetland ecosystems. Natural nanoparticles, such as mineral particles and  complex organic molecules are important vectors for contaminants. Their formation can enhance the mobility of otherwise immobile contaminants, providing a pathway for groundwater and river water pollution, and are important in terms of biogeochemical cycling and bioavailability. This study will characterise the evolution of natural nanoparticles and particle-contaminant associations during flooding and recession cycles at two contrasting sites in the Thames river basin. One site is in the Oxford floodplain, with a history of anthropogenic pollution, the second site is situated in the Boxford wetland area on the River Lambourn.

Characterisation and assessment of bioavailability of cloud-processed dust

E. Kadar, Plymouth Marine Laboratory

Consensus is that globally transported mineral dusts contribute to ocean fertilisation (Jickells et al., 2001). Whilst mainly free iron is known to enhance primary production, our recent research indicates that nano-sized iron particles can readily penetrate biological membranes (Kadar et al., 2010). We propose to investigate iron-rich nanoparticles derived from Saharan dust and their influence on phytoplankton productivity. We propose a suite of laboratory experiments using Fe rich Saharan dust (samples already available) exposed to the photochemical processes likely to occur during cloud formation. Sequential extractions and high resolution microscopic techniques will be used to demonstrate changes in morphology, mineralogy and chemical properties of cloud processed mineral dusts. Subsequently, bioavailability of "cloud-mediated" nanoparticles to a well described phytoplankton species (Emiliana huxleyi) will be investigated; changes in biochemical and physiological function of the microalgae will be assessed using flow cytometry, microscopy and fluorimetry (Readman et al., 2004) while batch cultures are obtained on growth media fortified with nano-Fe versus conventionally used EDTA-Fe The proposed study could offer opportunities to tackle global Fe-deficiency concerns .

Ecotoxicology test protocols for zinc oxide and cerium oxide nanoparticles

T. Galloway, University of Exeter

Nanotechnologies promise significant societal benefits, yet the ecotoxicology of manufactured nanoparticles released into the environment is not well understood. Our work is investigating the fate, behaviour and sublethal effects of OECD-selected and commercially important zinc oxide and cerium oxide nanoparticles to aquatic organisms. To fully interpret our results, we require more detailed knowledge of their physico-chemical behaviour in our biological systems. We request detailed characterisation of both zinc oxide and cerium oxide nanoprticles in different water systems to be able to proceed with more specific and intelligent toxicological studies.

Addressing biological uptake and maternal transfer capabilities of selected metal oxide nanoparticles

C.Tyler, University of Exeter

The effects of exposure pathways on responses to manufactured nanoparticles (MNPs) in aquatic organisms are largely unknown. We will apply 3 exposures scenarios to assess uptake, bio distribution and biological effects of selected metal oxide nanoparticles in fish. The exposures will include dosing CeO₂ NPs in combination with natural organic matter via the water, microinjection of various metal oxide NPs to zebra fish embryos, and dietary exposure of silver NPs to female guppies to investigate maternal transfer. We require access to the FENAC facility to provide comprehensive characterisation data on the particles in their raw state and in their exposure matrices, and to assess tissue burdens in exposed animals.

Assessment of TiO₂nanoparticle toxicity to aquatic and sediment dwellers

Prof. V. Stoneand Prof. T. Fernandes, Heriot-Watt University Edinburgh

This study aims to investigate the potential toxicity of different TiO₂ particles, varying in size, composition (crystal form) and coatings in a variety freshwater species (Pseudokirchneriella subcapitata, Daphniamagnaand Lumbriculus variegatus). The study allows comparisons between different types of organisms of different habitats in terms of their sensitivity to such particles. In order to understand the nature of the dose of the particles used, their potential for uptake into the organisms and their toxicity, a variety of physicochemical characteristics will be assessed.

Comparative study of the bioavailability of engineered vs naturally occurring Fe-nanoparticles

J.R. Readman, Plymouth Marine Laboratory

Recent increases in production of novel food additives in the form of Fe nano-particles bring attention to health risks that may be associated with overdose and/or failure of the iron-regulation mechanism. Since the human body has not evolved a mechanism to clear excess iron, disorders of iron balance, such as iron overload and iron deficiency, are among the most common diseases. Understanding the multiple factors that influence nanoparticle toxicity is essential from both human and environmental health prospective not only regarding nutrition, but also due to its growing diagnostic and therapeutic use. We propose simple in vitro systems to assess putative nano-particle versus solubilised Fe related toxicity indicators that may be used as standard bioassay and applied to other nanoparticles.

Assessment of the Utility of Primary Trout Hepatocyte Culture in Screening Nanoparticles for Potential Toxic Effects

Prof. C. Tyler, University of Exeter

With evidence that some engineered nanoparticles (ENPs) can induce biological harm and high likelihood for significant discharges into the aquatic environment, there is an urgent need to develop appropriate screens and tests for environmental risk assessment. High throughput in vitroscreens are urgently needed. We have used rainbow trout hepatocyte primary cell cultures to test for biological effects of a range of metal oxide ENPs, including TiO₂, ZnO, CeO₂ and Ag nano- and bulk. We have the biological analyses completed, but require detailed characterizations of the ENPs for a complete interpretation of our results.