Synthesis Of Alkenyl Glycomonomer And Properties Of Corresponding Glycopolymer Nanofibers

As a kind of biomacromolecules, carbohydrates are ubiquitous in living entities. Carbohydrates have high hydrophilicity and biospecificity. It has been found that the carbohydrates on the external cell membrane, known as the glycocalyx, play essential roles in many biological functions, especially serve as sites for the docking of cells, biomolecules and pathogens in a more or less specific recognition process. In this thesis, carbohydrates were tethered onto the polyacrylonitrile membrane surface by copolymerization, which is intended to improve the hydrophilicity of the membrane. The resultant copolymer may be potential for the seperation and purification of proteins on the basis of protein-carbohydrate recognition.A monomer containing carbohydrate, 2-(2-,3-,4-,6-tetra-O-acetyl-β-D-glucosyloxy) ethyl methacrylate (AcGEMA), was successfully synthesized by the reaction between peracetylated glucose and 2-hydroxyethyl methacrylate (HEMA) catalyzed with boron trifluoride-diethyl ether complex (BF₃·Et₂O). FT-IR and ¹H NMR spectra proved that theβ-glycoside was obtained stereospecificly via this route. After that, the monomer was copolymerized with acrylonitrile (AN) by free radical polymerization in solution. Glycopolymers with different carbohydrate contents and molecule weights were obtained. Water contact angles for the surface of dense membranes fabricated from the corresponding Copolymers demonstrated the enhancement of surface hydrophilicity after copolymerization.Nanofibers from the glycopolymers were prepared by electrospinning. It was found that higher copolymer concentration led to larger fiber diamer, so as for the flow rate. The fiber diameter decreased with the increase of the voltage and distance of electrospinning process as well as the sugar content in the glycopolymers.Adsorption of proteins such as Concanavalin A (Con A) and peanut agglutinin (PNA) onto the glycopolymer fibers was investigated. Laser scanning confocal microscope images confirmed the specific recognition of glycosylated polyacrylonitrile towards Con A which depended greatly on the content of glucose in the copolymer. On the other hand, the glycosylated copolymer had no binding activity towards PNA, a galactose specific lectin. These results proved the specific recognition between the glucose and Con A.