Coordination-cage-templated multivalent glycan arrays: effects of mixed-glycan composition and chain length on lectin...

The multivalent display of glycans in glycoclusters is typically achieved on geometry- and valency-disperse scaffolds such as polymers or nanoparticles, bearing a single glycan type; but the less explored heterogeneous display of multiple glycan types in a cluster may allow access to more avid or multifunctional glycomaterials. Here we deploy two distinct synthetic strategies to obtain self-assembled M₈L₁₂ coordination cages bearing 24 glycan residues of two distinct types, pendant from a strictly monodisperse, structurally predictable coordination cage scaffold formed in a single self-assembly step. Turbidimetry measurements revealed that the heterogeneous glycan displays result in significant differences in how the cages bind to representative lectins compared to homo-glycan arrays based on the same cages, underlining the value of structurally predictable, programmable, coordination cages as scaffolds which give access to increasingly complex glycomaterials, offering precise control over heterogeneous glycan displays which is not possible with other materials-led approaches. In addition we have examined the effect of increasing chain length (connecting cage core to pendant glycan array) and have found significant changes in lectin binding affinities with spacer length which will inform the design of next-generation glyco-cages.