Dr Helen Chappell
- Position: University Lecturer
- Areas of expertise: computational materials chemistry; biofilms on medical materials & biological tissue; teeth and bone pathologies; kidney stones; antibiotics in soilcomposite nanoparticles & complex structures
- Email: H.F.Chappell@leeds.ac.uk
- Phone: +44(0)113 343 0657
- Location: 7.63 EC Stoner
- Website: Member of the Bragg Centre | Treasurer of the Theoretical Chemistry Group of the Royal Society of Chemistry
Profile
I was appointed as a University Lecturer in September 2017. With a background in chemistry, materials modelling and molecular biology I obtained a PhD in 2006 from the University of Cambridge (Churchill College; Department of Materials Science & Metallurgy), focussed on the computational modelling of novel bone graft materials. I have since held several research posts, including a Career Development Fellowship (2013-2016) at the Medical Research Council Human Nutrition Research unit (Cambridge), focussing on the modelling of inorganic-organic interfaces of endogenous calcium phosphate nanoparticles found in the human gut. During this period I also held a College Research Associate position at Wolfson College, Cambridge. Prior to joining the MRC I spent 4.5 years employed as a Scientific Advisor at English Heritage where I was involved in, amongst other things, the protection of the Must Farm Bronze Age Settlement, the archaeological assessment of the new Sizewell C Nuclear Power Station, and the scientific assessment of offshore archaeology for several large wind-farm arrays off the East Anglian coast. I also acted as English Heritage scientific advisor for several episodes of the popular Channel 4 archaeological series Time Team.
Responsibilities
- B.Sc. & M.Sci. Food Science Programme Manager
- Module Leader - Food1010 Food: Origins and Form
- Module Leader - Food3140 Appraisal of Scientific Literature
Research interests
My research is focused on the computational modelling of organic-inorganic interfaces in biological, medical and environmental materials linked to health and disease. With particular emphasis on bacterial biofilms and composite nanoparticles, I am interested in the formation of biological composities and the way material properties (both natural and synthetic) influence disease pathologies.
In particular, my group is interested in:
- Molecular and atomic interactions at the interface of bacterial biofilms, particulalry within the cystic fibrosis lung.
- Acid demineralization of human teeth, and strategies for remineraliztion.
- Structure, formation and treatment of kidney stones.
- The development and effects of bacterial biofilms in contact with medical equipment.
- Causes and treatment of canine and human herniated spinal discs.
- Structure-function relationships of novel iron supplements composed of both inorganic and organic phases.
- Interactions of antiobiotic molecules with agricultural soil minerals and how these interactions affect retension and uptake by plants and lower animals.
I'm very happy to speak with anyone interested in carrying out a modelling-based PhD in any of these areas.
Key Research Themes
Antimicrobials and Biofilms
I have two PhD students ( University and EPSRC funded) and a summer student (Leeds Biofilm Network funded) investigating the structure and function of the extracellular matrix of bacterial biofims. We are particulalry focussed on the Pseudomonas aeruginosa bacterium, which is an often fatal infection in patients with Cystic Fibrosis. This bacterium is largely antibiotic-resistant, and has been highlighted by the WHO as a ‘Priority 1’ critical pathogen requiring urgent R&D work, to find alternative antimicrobial strategies. In my group we have been looking at the basic science of the biofilm structure – a sticky, dense, carbohydrate rich matrix, which provides excellent protection for bacterial colonies – which has previously been rather neglected. We have published a number of papers in this field recently, and it is a rapidly growing area of interest for the group.
Pharmaceuticals in Agricultural Soils
Veterinary pharmaceuticals accumulate in agricultrual land through animal excretion and the spreading of animal manure as fertilizer. It is recognised that these bioactive drugs are able to have a broad and deterimental impact on soil structure. More worringly, certain catagories of drugs, e.g. antiobiotics, are implicated in the development of antimicrobial resistance (AMR) and the spread of AMR pathogens to humans in the food chain. We are therefore interested in how these drugs interact with soil components, e.g. clay minerals and organic matter, and how these interactions determine whether certain pharmaceuticals are retained in the soil structure or are released into pore-water, which provides a conduit to streams and rivers.
Nanoparticles in the Gut
We explore the structure and function of nanoparticles found in the human gut. These may be endogenous or man-made, but all have important properties linked to health and disease. In particular, our most recent work shows that calcium phosphate particles that are secreted in the gut (millions, every day, by everyone) act as Trojan Horses, delivering pieces of food protein or bacteria to the cells of the immune system, where they are 'unpacked' and start a cascade of immuno-tolerant signals.<br><br>Interestingly, in patients with Crohn's disease, this pathway fails, which leads to inflammation after consumption of food. We use computational modelling to understand the atomic structure of these particles and how they interact with protein fragments. Eventually, similar particles produced in the laboratory may be used as effective drug delivery systems, to treat chronic gastrointestinal conditions such as Crohn's or ulerative collitis.
Inorganic-Organic Interfaces
In biology there are a surprising number of inorganic-organic interactions. For example, our bones and our teeth are composed of both strong mineral (inorganic) and mixtures of complex proteins (organic) and it is this composite nature that gives them their particular properties, e.g. bones are strong but they aren't brittle; if you fall over your bones don't just shatter because the mineral component is bound to protein.<br><br>These interactions are also becoming very important in the design and manufacture of complex nanoparticles - used, for example, as drug delivery systems, coatings or in imaging.
The Structure of Drugs and Supplements
Our aim is to establish the fundamental chemistry and characteristics of innovative medicines, for example iron supplements which consist of an iron-oxide mineral phase and a coating of organic ligands. When dealing with structures at very small scales, it can be very difficult to obtain experimental data that gives accurate information about the atomic and chemical structure.<br><br>This is where simulation and modelling plays a vital role. Our group works closely with experimental colleagues in throughout the world, to make sure that experiment and theory are used hand-in-hand to bring new understanding.
Our research is highly interdisciplinary. We are connected with various experts who have complementary strengths and facilities, both within our School of Food Science and Nutrition and outside in other schools, universities and institutions:
- The Queen’s Veterinary School Hospital, University of Cambridge
- The Biomineralisation Group, School of Dentistry, University of Leeds
- The McDonald Institute of Archaeological Science, University of Cambridge
- Disordered Materials Group, ISIS Neutron and Muon Source, Harwell.
Qualifications
- Ph.D, Bone Graft Materials Modelling, (Cambridge)
- M.Phil. Modelling of Materials, (Cambridge)
- M.Res. Biomolecular Science, (York)
- B.Sc. (Hons), 1st Class, Chemistry, (Open)
Professional memberships
- Member, Royal Society of Chemistry
- Member, EPSRC Peer Review College
- Member, NERC Peer Review College
- Member, The Microbiology Society
Student education
- Programme Manager for the BSc and MSci in Food Science
- Module Leader and Lecturer on Food1010 Food: Origins and Form
- Module Leader Food3140 Critical Appraisal of Scientific Literature
- Lecturer in organic chemistry on Food1210 Physicochemical Properties of Food
- Research supervisor for final year undergraduate and postgraduate projects, across all degree programmes
- Personal Academic Tutor