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A convenient synthetic route to a new type of artificial glycoconjugate polymer has been designed to develop biomedical materials using oligosaccharide moieties as recognition signals. An amino function was introduced to the reducing end of lactose and N,N‘-diacetylchitobiose with ammonium hydrogen carbonate and then was allowed to react with p-vinylbenzoyl chloride. The N-glycosidation proceeded stereospecifically in one flask to give only the β-glycoside without any protection and deprotection steps. The resulting p-vinylbenzamide glycoside derivatives were homo- and copolymerized with acrylamide using 2,2‘-azobisisobutyronitrile as initiator in dimethyl sulfoxide at 60 °C. The interaction of the glycopolymers with lectins was investigated by means of a two-dimensional immunodiffusion test in agar and inhibition of the hemagglutinating activity. The specificity of lectins with these glycopolymers was similar to that reported for naturally-occurring glycoconjugates. Binding between wheat germ agglutinin lectin (WGA) and poly((p-vinylbenzamido)-β-diacetylchitobiose) was increased by 103 times compared with that of the oligosaccharide itself. The enhancement was attributed to the presence of the hydrophobic phenyl aglycon as well as the high density, multiantennary disaccharide ligands along the polymer chain. The present synthetic method is useful to introduce biologically important, complex oligosaccharides into glycopolymers.

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ABSTRACT. Hepatocyte transplantation is expected to become a novel method for treatment of liver disease. However, many questions remain regarding this approach, especially concerning donor cells. To evaluate whether human amniotic epithelial cells can be used as a cell source for hepatocyte transplantation, hepatic gene expression and functions of human amniotic epithelial cells were analyzed. Reverse transcription-polymerase chain reaction analysis demonstrated that human amniotic epithelial cells expressed albumin, α1-antitrypsin, and other hepatocyte-related genes. Cultivated human amniotic epithelial cells demonstrated albumin production, glycogen storage, and albumin secretion consistent with the hepatocyte gene expression profile. In organ culture, the amnion secreted 30-fold larger amounts of albumin than human amniotic epithelial cells in monolayer culture. Moreover, in organ culture the amnion also secreted α1-antitrypsin. Following transplantation into mice, the amnion survived and secreted albumin. These observations suggest that transplantation of human amniotic epithelial cells and/or amnion could be novel therapeutic strategy for treatment of hepatic diseases, including α1-antitrypsin deficiency.