Glycopolymers

Natural saccharides (carbohydrates) are highly important as biomass, food, and raw materials. As a result, their chemical modification has been investigated from early on to develop a variety of industrial products like fibers. Due to their high biocompatibility and biodegradability, carbohydrate-based materials (Fig. 5.17) have also been widely used for pharmaceutical and medical applications. 

FIGURE 5.18 Schematic representation of a ceU membrane decorated with glyco-polymers indicating their specific biointeractions. Source Voit and Appelhans [39a], figure 1. Reproduced with permission Irom John Wiley Sons. 

Synthetic glycopolymers of various architectures have been prepared in recent years using the fast development of controlled polymerization techniques and the very efficient coupling reactions in polymer analogous approaches. Both, linear and globular polymer structures that have been obtained by synthesizing dendritic, starlike, or micelle-like structures or nanogels have received much attention. 

Glycodendrimers are mainly considered in various biomedical fields [39b] because of their high biocompatibility in combination with multivalency and specific interactions that are important, for example, for protein and cell membrane binding and recognition processes. The use of glycopolymers as viral and bacterial antiadhesion drugs and for inhibition of infections is very prominent (see also Sections 6.2 and 6.3). 

The most important synthetic approaches toward linear and globular/ branched glycopolymers will be highlighted here. Two main approaches are addressed preformation of reactive polymers, which can be further modified by polymer analogous reaction with sugar moieties, and direct incorporation of glyco units during the polymer formation process. 

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Artificial glycopolymers having a-galactosyl epitope are of interest from the viewpoint of medical transplantation of pig liver since they can block im-... 

Scheme 27. Noncovalent functionalization of SWNTs by using an amphiphilic glycopolymer, ending with a lipid tail for mucin mimicry.249...

Approaches to the synthesis of glycosyl phosphate diesters as constituents of glycopolymers of the outer membrane of bacteria, yeasts and protozoa and the latest achievements in the field have been profoundly reviewed and will not be covered in this chapter.1,2... 

Figure 15.2 Hyperbranched sialosides and related glycopolymers can inhibit microbial attachment to host tissues by blocking their receptor sites...

Figure 15.3 Various strategies leading to dendronized or hyperbranched glycopolymers. (A) grafting of dendronsto pre-formed polymers (B) polymerization of dendron monomers (C) grafting dendrimers on pre-formed polymers...

Nishimura and Yamada [10-11] introduced a water-soluble polymeric support having a linker recognized by ceramide glycanase for a synthesis of ganghoside GM3 (17). Synthesis of the polymerizable lactose derivative (14) with a ceramide glycanase sensitive linker is shown in Scheme 10.3. The lactosyl ceramide (Lac-Ger) mimetic glycopolymer (15) is obtained from the monomeric precursor (14) by co-polymerization with acrylamide. 

Some reviews have been published on the synthetic carbohydrate-based polymers and glycopolymers [11-15]. However, they refer mainly to poly(vinylsaccharide)s and other conventional functionalized polymers having sugars as groups pendant from the main chain of the polymer. In this chapter we shall describe those sugar-based monomers which lead to polymers having the sugar units incorporated into... 

Figure 13.4 A schematic showing some of the frameworks that have been reported for the study of protein-carbohydrate interactions. Carbohydrates are represented as cyclohexane. (Top) Glycodendrimer, carbohydrate-functionalized nanoparticle, and star polymer. (Bottom) Linear glycopolymer, carbohydrate-functionalized protein, and carbohydrate-functionalized surface.

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