Glycopolymers are an exciting class of synthetic macromolecules which can display increased affinity towards carbohydrate binding proteins (especially lectins). This is due to the cluster glycoside effect, which results in a non-linear increase in affinity as the valency increases. These multivalent glycan interactions are involved in a range of biological processes such as cell-cell and cell-pathogens communications, and hence their application as decoys in anti-adhesive therapy or to modulate signalling is of huge interest.
Most previous studies on glycopolymers involve relatively simple monosaccharides, which do not enable reproductions of the complex 3-D presentation found in native glycans and hence do not have high selectivity. Furthermore most binding studies are against model plant lectins, and use simple aggregation assays.
To address the above, we will present a practical method to obtain water soluble amino-oxy functional polymers which can be directly reacted with reducing glycans enabling aqueous post-polymerization modification and assembly of the glycans into polymers or nanoparticles. This strategy is useful as it allows the use of both larger glycans and those bearing sulphated and other residues which are crucial for affinity in some cases. The route involves a two-step modification of poly (N-hydroxyethyl acrylamide) (PHEA) obtained from RAFT polymerization then subsequent glycan capture. We will present both the synthesis and the utility of this to study their interactions to human and pathogenic carbohydrate binding proteins using colourmetric assays and biolayer interferometry.