Biotin α-end-functionalized gradient glycopolymers synthesized by RAFT copolymerization

Biotinylated gradient glycopolymers have been synthesized via RAFT copolymerization of an acrylamide derivative of galactose with N-acryloylmorpholine in the presence of a biotin CTA. The polymerization was controlled with a linear increase in molecular weights up to 80% conversion. Copolymer chains have a gradient microstructure with an increasing proportion of galactose units towards the omega chain end. The presence of the biotin ligand at the a end of the chains was confirmed by H-1 NMR and MALDI-ToF MS. This strategy based on the use of a biotin-CTA instead of a post-polymerization labelling of the chains resulted in a high percentage of alpha-functionalized chains (92-95%). Such alpha-end-functionalized glycopolymer chains may interact with streptavidin-modified surfaces.