Glycoclusters and their applications as anti-infective agents, vaccines and targeted drug delivery systems

Abstract

This chapter reviews the most relevant and recent reports on the applications of glycoclusters as inhibitors and antiadhesive agents against bacteria and viruses, synthetic vaccines, and site-specific drug and gene delivery systems. A common strategy to achieve these goals is the targeting of carbohydrate-binding proteins (lectins) present on the surface of pathogens and tumor cells. Such target lectins are typically involved in cell recognition, signaling, and adhesion or are overexpressed in cell proliferation and tumor development. Multivalency is crucial for the enhancement of such carbohydrate-protein interactions, which are otherwise too weak in biological terms for such applications. In addition, size and spatial arrangement matching between the glycocluster and the biological target is important to obtain a high binding affinity in many cases. A large number of different scaffolds have been used for building such multivalent structures, including cyclodextrins, calixarenes, oligo- and cyclooligopeptides, pentacyclen, pentaerythritol, and saccharides, among others, giving rise to an enormous variety of modes of carbohydrate display with different topologies and valencies.