Sequential Double “Clicks” toward Structurally Well-Defined Heterogeneous N-Glycoclusters: The Importance of Cluster Heterogeneity on Pattern Recognition In Vivo

: Structurally well-defined heterogeneous N-glycoclusters are prepared on albumin via a double click procedure. The number of glycan molecules present, in addition to the spatial arrangement of glycans in the heterogeneous glycoclusters, plays an important role in the in vivo kinetics and organ-selective accumulation through glycan pattern recognition mechanisms.