Artificial Glycoconjugate Polymers

Abstract

Well-defined polymers having pendant oligosaccharide chains as the recognition signals, termed “artificial glycoconjugate polymers”, are described. The first part of this review treats the applications of oligosaccharide-substituted polystyrenes to cell-specific biomedical materials using the oligosaccharides as the key participants in cell-substratum recognitions. Lactose-carrying polystyrene abbreviated as PVLA is a useful substratum for culture of parenchymal liver cells (hepatocytes). Owing to the hydrophilic-hydrophobic structure, PVLA formed compactpacked (super molecular) conformations in water and were adsorbed on the surface of polystyrene culture dishes. As the result, highly-concentrated galactose signals protruded from the material surfaces to interact strongly with asialoglycoprotein receptors of the cell surfaces. Cell-culture systems using the strong interactions between pancreatic cells and maltose-carrying polystyrene and between erythrocytes and a reducing glucose-carrying polystyrene are also of interest.The second part is concerned with our synthetic approaches to four different types of artificial glycoconjugate polymers having highly-concentrated carbohydrate signals. (1) Chemoenzymatic synthesis of polyacrylamide derivatives, especially, having β-linked N-acetyllactosamine moiety, a major component of oligosaccharide chains of glycoproteins. (2) Multi-branched graft copolymers. (3) Branched (1→6) -α-mannan polysaccharide having pendant α-mannose units. (4) Oligosaccharide-substiuted poly (γ-glutamate).