Patricia Monteiro, Senior Scientist (Lead, Patricia.Monteiro@Astrazeneca.com), Thomas Floyd, Senior Scientist, Silvia Sonzini, Associate Principal Scientist & Richard England, Associate Principal Scientist - Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca
Daniel Lester, Platform Manager Polymer Characterisation Research Technology Platform (RTP), Paul Wilson, Group Leader, Department of Chemistry
Outline of Project:
Active targeted polymeric systems have the potential to selectively deliver the drug molecules to diseased (cancer) cells, thus offering important therapeutic benefits for patients by improving efficacy and decreasing side effects. Upon systemic injection, the ligand conjugated polymeric systems will bind to receptors that are highly expressed only on cancer cells, get internalised and be exposed to intracellular stimuli where the drug will be released.
In this project, we will screen and optimise the conditions of the conjugation reaction and purification of the active targeted polymeric materials as these factors directly impact the effectiveness and quality of these materials. They will be obtained after conjugation reactions where ligands such as RGD (arginine-glycerine-aspartate) peptides are covalently attached to functional end groups present in the polymers. Afterwards, the system will be purified in order to remove the unreacted ligands.
Here, we aim to investigate analytical techniques for tracking reaction kinetics and obtain the optimum conditions for conjugation using dendritic and polymeric polymers with different architectures) systems. These targeted materials will be screened according to their biomolecular interactions (ligand-receptor affinity) using BLI/SPR (biolayer interferometry/surface plasmon resonance) and some will be selected for in vitro assessments using cell lines expressing/overexpressing appropriate receptors.
In order to achieve this a novel approach to measurement science will be implemented. Initially a model system of freely available polymers, linkers and proteins will be used to method develop suitable analytical instrumentation to be used.
Analysis of the reactions will take advantage of the increase in size over each reaction step, and therefore will be able to use techniques such as: DLS (dynamic light scattering) to directly monitor increase in size, SEC (size exclusion chromatography) to monitor hydrodynamic volume, and DOSY NMR (diffusion ordered spectroscopy nuclear magnetic resonance) to measure diffusion coefficients. With DLS and DOSY NMR online reaction monitoring will be applied to determine the radius of gyration and diffusion over the course of the reaction. The Polymer RTP has a flow NMR instrument which will allow us to reaction monitor from a reaction vessel, allowing us better control over the reaction conditions.
Once a suitable analytical regime has been determined, a library of relevant materials can be screened to obtain mechanistic information and further modifications can be made to the linkers used to allow for better control over the conjugation process.