Name of scholarship/program
Novel strategy for the safe and effective delivery of insecticides
There is urgent need for new strategies to control insect pests that transmit parasitic diseases and those that devour crops. Climate change will result in the geographical movement of pests, adding to the existing problems and uncertainties of disease vector control and securing global food production. Combating these threats relies heavily on chemical pesticides as components of integrated pest management programmes. However, insect pests (e.g. mosquitoes) are rapidly developing resistance to current controls and many chemicals are now known to damage the environment by killing non-target animals and by contaminating water supplies. Recently discovered biological molecules, e.g. double-stranded RNA, animal venoms, have great potential as insect control agents but lack penetration across the insect cuticle and are often chemically unstable.
Eligibility and other criteria
Therefore new classes of insecticides are required to combat resistance to the existing insecticide solutions, together with the development of novel delivery systems that minimise non-target toxicity and environmental damage. This proposal brings together for the first time two strong areas in Leeds (Particle science and Sustainable agriculture) and at Food and Environment Research Agency (FERA, Invertebrate pest management) to develop a novel delivery system for insect control agents using technology invented by Dr OJ Cayre in the Institute of Particle Science and Engineering (IPSE) for creating smart microcapsules with pH-responsive porosity. Our approach will exploit the large difference in pH of the digestive tract of insects and other animals for the safe delivery of biological agents. The pH in the lumen of insects, such as caterpillars and mosquitoes, is strongly alkaline (pH 11). This will allow us to design smart polystyrene latex (PS-latex) colloidosomes that can be loaded with biomolecules at pH 3-7. Under these conditions the colloidosomes will retain these biomolecules and protect them from the natural environment. Upon ingestion and exposure to the alkaline lumen of the insect intestine, the biocides will be released to directly attack and damage the gut epithelium, resulting in rapid loss of appetite, reduced resistance to pathogens and eventual septicaemia.
The student will collaborate with Dr Olivier Cayres research group who are developing nanomaterials for loading with biomolecules that will target critical aspects of insect physiology. Of particular interest will be: (i) chitinase enzymes that will degrade the chitinous peritrophic membrane that lines the midgut and which serves as a critical barrier to pathogenic microbes; (ii) peptides known to be toxic to several insect pest species (e.g. allatostatins and their biostable analogues); (iii) protease inhibitors for disrupting digestion; (iv) double-stranded (ds) RNA designed for selective interference with the expression of critical gut proteins. The efficacy of these loaded colloidosomes to disrupt insect feeding and growth will be determined by comparison with the unprotected proteins and dsRNA. A range of insect pests (mosquitoes, lepidopteran insects, flies) are available for assessing the efficacy of this novel delivery system, depending on the interests of the student. Some of the work will be conducted with the Invertebrate Pest Management group at FERA, York.
Self-Funded PhD Students Only:
If you have the correct qualifications and access to your own funding, either from your home country or your own finances, your application to work with this supervisor will be considered.
Applications accepted all year round
Additional information, and important URL
The student will collaborate with Dr Olivier Cayres research group who are developing nanomaterials for loading with biomolecules that will target critical aspects of insect physiology
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