New group members!
We welcome 2 new PhD students to the group, Aaron King and Craig Dedman, as well as Masters student Markus Grueter.
The group’s latest paper in Chemical Science can now be viewed here.
Title: Magnetically activated adhesives: Towards on-demand magnetic triggering of selected polymerisation reactions
Abstract: On-demand initiation of chemical reactions is becoming increasingly popular in many areas. The use of a magnetic field to trigger reactions is an intriguing concept, with vast potential in both research and industrial settings, though it remains a challenge as yet unsolved. Here we report the first example of on-demand magnetic activation of a polymerisation process using an anaerobic adhesive formulation as an example of this new approach toward triggering polymerisation reactions using an external magnetic field. Our strategy involves the use of a colloidal system comprising functional methacrylate ester monomers, peroxide and CuII-salt as polymerisation initiators and magnetic nanoparticles coated with an oxidising shell. This unique combination prevents reduction of the reactive transition metal (CuII) ion by the metal substrates (steel or aluminium) to be joined – hence inhibiting the redox radical initiated cationic polymerisation reaction and efficiently preventing adhesion. The polymerisation and corresponding adhesion process can be triggered by removal of the functional magnetic particles using a permanent external magnet either prior to formulation application or at the joint to be adhered, enabling the polymerisation to proceed through CuII-mediated reduction. This new approach enables on-demand magnetically-triggered reaction initiation and holds potential for a range of useful applications in chemistry, materials science and relevant industrial manufacturing.
Poster Prize for Charlotte Fletcher
Congratulations to PhD student Charlotte Fletcher who won the ‘Best Poster’ Award at SCI’s Materials Science Conference and BBQ in London in September 2017. Well deserved for lots of hard work! Link
Different place, same research!
Gemma has now officially moved to UCL’s Department of Chemistry, as of 13th July. Her research team will be split between UCL and the University of Warwick, but the research into all things nano will continue!
Paper published in Scientific Reports
Title: Rare Earth Doped Silica Nanoparticles via Thermolysis of a Single Source Metallasilsesquioxane Precursor
Abstract: Rare earth metal doped silica nanoparticles have significant advantages over traditional organic dyes and quantum dots. Silsesquioxanes are promising precursors in the production of silica nanoparticles by thermolysis, due to their structural similarities with silica materials. This manuscript describes the production of a new Eu(III)-based metallasilsesquioxane species and its use as a single source precursor in the thermolytic production of luminescent rare earth metal doped silica nanoparticles with characteristic emission in the visible region of the spectrum.
Gemma-Louise was awarded best Early Career Presentation at the 7th Annual Royal Society of Chemistry Chemical Nanoscience Symposium in the University of Newcastle on 28th March 2017.
October 2016 sees the arrival of Charlotte Fletcher, who is joining to group to start her PhD in collaboration with Profs. Andrew McAinsh and Rob Cross in Warwick Medical School, as well as two MChem students, Gabrielle Newson and Claudia Fryer. Welcome all!
Congratulations to 1st year PhD student Henry Lee, who has won 2nd prize in the Materials and Analytical Science Annual Conference – well done!
Paper published in Emerging Investigators Issue of Journal of Materials Chemistry B
This paper has been highlighted on the back cover of the special Emerging Investigator issue
Title: Heparin-stabilised Iron Oxide for MR Applications: A Relaxometric Study
Abstract: Superparamagnetic nanoparticles have strong potential in biomedicine and have seen application as clinical magnetic resonance imaging (MRI) contrast agents, though their popularity has plummeted in recent years, due to low efficacy and safety concerns, including haemagglutination. Using an in situ procedure, we have prepared colloids of magnetite nanoparticles, exploiting the clinically approved anti-coagulant, heparin, as a templating stabiliser. These colloids, stable over several days, produce exceptionally strong MRI contrast capabilities particularly at low fields, as demonstrated by relaxometric investigations using nuclear magnetic resonance dispersion (NMRD) techniques and single field r1 and r2 relaxation measurements. This behaviour is due to interparticle interactions, enhanced by the templating effect of heparin, resulting in strong magnetic anisotropic behaviour which closely maps particle size. The nanocomposites have also reliably prevented protein-adsorption triggered thrombosis typical of non-stabilised nanoparticles, showing great potential for in vivo MRI diagnostics.
Cancer Research UK Grant
Gemma-Louise and a team of clinicians and scientists from around the UK receive a research Grant from CRUK to investigate new approaches for the early diagnosis of bowel cancer.
The Group welcomes new members!
October saw the arrival of the Davies’ group’s first PhD students – Henry Lee and Jonathan Strong, as well as 2 new MChem students.
Paper published in Chemical Communications
Title: Ligation Driven 19F Enhancement in Self-Assembled Ln(III) Complexes
Abstract: Strong bidentate ligation between a fluorinated isophthalate and binuclear lanthanide-DO3A species yields a new class of 19F NMR agent with very high nuclear relaxation rates at physiologically-relevant pH.
Paper published in Journal of Materials Chemistry B
Title: Siderophore-Inspired Nanoparticle-based Biosensor for the Selective Detection of Fe3+
Abstract: Inspired by nature’s exploitation of the 1,2-dihydroxybenzene unit (or catechol) in mammalian and bacterial siderophores, we report the first example of a nanoparticle sensing system that utilises the strong catechol–Fe3+ binding motif to trigger nanoparticle aggregation, promoting a powerful optical response. Gold nanoparticles are functionalised with RAFT polymerisation-prepared water-soluble poly(N-hydroxyethyl acrylamide) containing a catechol moiety at the α-chain-end. A strong red-to-purple colorimetric response occurs in the presence of Fe3+ at serum concentrations (8–25 μM) in saline solution. Sodium chloride is critical in generating a strong optical output, as is the length of polymer used to coat the AuNPs. This behaviour is also demonstrated to be selective for Fe3+over a host of other biologically relevant ions.
Paper published in ACS Macro Letters
Title: Isothermally-responsive Polymers Triggered by Selective Binding of Fe3+ to Siderophoric Catechol End-groups
Abstract: Thermoresponsive polymers have attracted huge interest as a way of developing smart/adaptable materials for biomedicine, particularly due to changes in their solubility above the LCST. However, temperature is not always an appropriate or desirable stimulus given the variety of other cellular microenvironments that exist, including pH, redox potentials, ionic strength, and metal ion concentration. Here, we achieve a highly specific, isothermal solubility switch for poly(N-isopropylacrylamide) by application of ferric iron (Fe3+), a species implicated in a range of neurodegenerative conditions. This is achieved by the site-specific incorporation of (Fe3+-binding) catechol units onto the polymer chain-end, inspired by the mechanism by which bacterial siderophores sequester iron from mammalian hosts. The ability to manipulate the hydrophilicity of responsive systems without the need for a temperature gradient offers an exciting approach toward preparing increasingly selective, targeted polymeric materials.
Emerging Nanomaterials in Healthcare Conference 2014
The one-day conference, ‘Emerging Nanomaterials for Healthcare’ was held at the University of Warwick on 28th November 2014. This meeting was designed to stimulate new thoughts in the challenging area of designing, developing and applying nanotechnology for medical applications. Several Academic experts from leading Universities throughout the UK were invited to share their recent work in this area, as well as their experiences in this highly interdisciplinary field.
The programme for the day included 7 academic presentations covering interdisciplinary areas from the synthesis and design of nanostructured materials, to investigations into understanding of the behaviour of these materials when interacting with human cells. Refreshment breaks allowed delegate and speaker interactions to promote discussions and collaborations. The day was rounded off with a panel discussion, which encouraged delegates to pose questions to our panel of speakers and seek advice relating to the topics discussed throughout the day.
Invited speakers included Prof Marina Resmini (Queen Mary University London), Dr David Fulton (Newcastle University), Prof Nguyen TK Thanh (University College London), Dr Catherine Berry (University of Glasgow), Dr Sebastian Spain (University of Nottingham) and Dr Matthew Gibson (University of Warwick), with an additional contributed talk from Daniel Phillips (University of Warwick). Eighty-one delegates registered to attend the conference, including Academics, Postdoctoral Researchers and Postgraduate Students from Universities throughout the UK and Ireland. Company delegates included a representative of the RSC membership team (John Hirwe), ATG Scientific and Warwick Ventures. Twenty two delegates brought and presented Academic posters.
Thanks to our generous sponsors: The University of Warwick, the Institute of Advanced Study, the Materials Global Research Priority, the Royal Society of Chemistry’s Materials Chemistry Division, Nanoscale, the Journal of Materials Chemistry B, ATG Scientific and the Polymer Club.
Paper published in Carbohydrate Research
Title: Synthesis and Characterisation of Glucose-Functional Glycopolymers and Gold Nanoparticles: Study of their Potential Interactions with Ovine Red Blood Cells
Abstract: Carbohydrate–protein interactions can assist with the targeting of polymer- and nano-delivery systems. However, some potential protein targets are not specific to a single cell type, resulting in reductions in their efficacy due to undesirable non-specific cellular interactions. The glucose transporter 1 (GLUT-1) is expressed to different extents on most cells in the vasculature, including human red blood cells and on cancerous tissue. Glycosylated nanomaterials bearing glucose (or related) carbohydrates, therefore, could potentially undergo unwanted interactions with these transporters, which may compromise the nanomaterial function or lead to cell agglutination, for example. Here, RAFT polymerisation is employed to obtain well-defined glucose-functional glycopolymers as well as glycosylated gold nanoparticles. Agglutination and binding assays did not reveal any significant binding to ovine red blood cells, nor any haemolysis. These data suggest that gluco-functional nanomaterials are compatible with blood, and their lack of undesirable interactions highlights their potential for delivery and imaging applications.
Paper published in Small
Title: Magnetic Nanoparticles to Recover Cellular Organelles and Study the Time Resolved Nanoparticle-Cell Interactome throughout Uptake
Abstract: Nanoparticles in contact with cells and living organisms generate quite novel interactions at the interface between the nanoparticle surface and the surrounding biological environment. However, a detailed time resolved molecular level description of the evolving interactions as nanoparticles are internalized and trafficked within the cellular environment is still missing and will certainly be required for the emerging arena of nanoparticle-cell interactions to mature. In this paper promising methodologies to map out the time resolved nanoparticle-cell interactome for nanoparticle uptake are discussed. Thus silica coated magnetite nanoparticles are presented to cells and their magnetic properties used to isolate, in a time resolved manner, the organelles containing the nanoparticles. Characterization of the recovered fractions shows that different cell compartments are isolated at different times, in agreement with imaging results on nanoparticle intracellular location. Subsequently the internalized nanoparticles can be further isolated from the recovered organelles, allowing the study of the most tightly nanoparticle-bound biomolecules, analogous to the ‘hard corona’ that so far has mostly been characterized in extracellular environments. Preliminary data on the recovered nanoparticles suggest that significant portion of the original corona (derived from the serum in which particles are presented to the cells) is preserved as nanoparticles are trafficked through the cells.
MLS Research Bursary
Gemma-Louise is awarded a Medical and Life Science Research Bursary to support her research.
Royal Society Research Grant
Gemma-Louise is awarded a Royal Society Research Grant to support her research.
Royal Society Visit
Gemma-Louise visits the Royal Society and meets the President of Ireland as part of his historic UK visit.