Synthetic carbohydrate ligands – also widely known as glycopolymers – are known to undergo numerous recognition events when interacting with their corresponding lectins. Interactions are greatly enhanced due to the multivalent character displayed by the large number of repeating carbohydrate units along the polymers (pendant glycopolymers); therefore, resulting what is called the “glycocluster effect”. Moreover, the strength and the availability of these multivalent recognitions can be tuned via the architecture of the glycopolymers. Hence, understanding the mechanistic interactions between the types of lectins (plant, animal, toxin and bacteria) with their synthetic ligands is crucial. This review focuses on the synthesis of pendant glycopolymers via various synthetic pathways (free radical polymerization, NMP, RAFT, ATRP, cyanoxyl mediated polymerization, ROP, ROMP and post-polymerization modification) and their interactions with their respectively lectins.

The present communication explores a novel avenue to glycopolymer-block-poly(vinyl acetate) polymers by a combination of reversible addition fragmentation chain transfer (RAFT) chemistry and Huisgen 1,3-dipolar cycloaddition (i.e., so-called ‘click’ chemistry) under mild reaction conditions. Such block copolymers are—because of the strongly disparate reactivity of the two monomers—otherwise not obtainable. Poly(vinyl acetate) that has an azide end group (Mn 6800 g mol–1, PDI 1.15) was treated with poly(6-O-methacryloyl mannose) (Mn 7600 g mol–1, PDI 1.11) in the presence of 1,8-diaza[5,4,0]bicycloundec-7-ene and copper(i) iodide. The resulting poly(vinyl acetate)-block-poly(6-O-methacryloyl mannose) had a number-average molecular weight of 15 400 g mol–1 and a PDI of 1.48, which indicates that while the cycloaddition had occurred the resulting polymer distribution featured a considerable width. The resulting slightly amphiphilic block copolymer was subsequently investigated with regard to its self-assembly in aqueous solution. Dynamic light scattering studies indicated a hydrodynamic diameter of close to 200 nm. Transmission electron microscopy studies indicate the formation of rods as well as spheres with transitions between these two phases. However, the segregation between core and shell in the spheres is not pronounced; such behaviour is expected for weakly amphiphilic block copolymers.