Overview
Glycoprotein therapeutics are widely seen as the next generation of drugs. 80% of new therapeutic drugs in phase 3 development are ‘biologics’. However, the early detection of critical glycosylation changes in biopharma production (i.e. in the drug producing cells) and the rapid and sensitive identification and separation of closely related protein-drug glycoforms presents an industry wide problem.
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Current technology: Traditional chromatographic methods, such as ion exchange chromatography, size exclusion chromatography and hydrophobic interaction chromatography are used to separate glycoforms but all of ththem lack the selectivity required to separate and identify closely related glycoproteins or glycoforms. These critical variations are usually a matter of small differencdes in neutral glycans or alpha- or beta- forms of sugars. Presently, such glycoprotein analyses and separations is difficult, and is carried out by RP-HPLC followed by high-end MALDI-ToF Mass Sepctrometry, which is relatively expensive, time consuming and requires a MS technical exper specialist. The entire industry has a requirement for a relatively easy, fast and sensitive system for glycoproprotein analysis and separation.
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The project aimed to develop a low-cost and easy-to-produce glycopeptide separation platform. This was to be based on highly porous polymeric materials that were to be utilised for the attachment of biomolecules that have very selective carbohydrate-binding properties. The project was a highly interdisciplinary project at the interface of polymer and material science, biotechnology and separation science.
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First part of the project aimed at the production of porous polymers and their functionalization to increase the amount of reactive groups in the material. This was undertaken by the synthesis of a polymerised high internal phase emulsion polyHIPE with a protected reactive monomer, vinyl benzyl phthalamide being added to the monomer emulsion mixture. Subsequent work focused on the graft polymerisaiton of tert-butyl acrylate via ARGET ATRP from the surface of the porous material. This was analysed by dynamic scanning calorimetry to quantify the amount of grafting. Following the deprotection of the t-Bu group to then give a surface funcitonalised with carboxylic acid groups. Then the project focused on the development and application of methods to bioconjugate lectins onto these materials. The lectin immobilized porous materials were then tested for the separation of different glycoprotein types.
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However, it was observed that there was non-specific binding of glycoproteins onto the polyHIPE material, which we believed to be due to the styrenic nature of the base material even though there was polyacylic acid grafted from the surface.
Additional Benefits of Project
Supervising PhD students
This was very rewarding, I co-supervised a PhD student who was investigating the development of electrospun fibers from polyesters, synthesised from the enzymatic ring-opening polymerisation of an unsaturated macrolactone. It was a multidisciplinary project that included collaboration not just within RCSI, but also with Trinity College Dublin. This led to one co-authored publication in 2017 in Biomacromolecules. The publication itself which will be made open access after the embargo from the publisher. In addition data used for the publication will also be made open access.
I undertook part-time lecturing of a postgraduate course on Bioseparations and Chromatography (related to polymer chemistry and functionalisation of polymeric materials) in the School of Biotechnology, Dublin City University (October 2017). There was a total of 16 contracted contact hours. In addition to this I also set and marked an exam question based around the lectures given. This was a key step, in me gaining experience to help me in becoming a lecturer in the future.
Part-Time Lecturing
Heise Group
