Synthesis of Functional Polymer Brushes Containing Carbohydrate Residues in the Pyranose Form and Their Specific and Nonspecific Interactions with Proteins.

Three novel N-substituted acrylamide monomers contg. different carbohydrate residues, 2’-acrylamidoethyl-α-D-mannopyranoside, 2’-acrylamidoethyl-β-D-glucopyranoside, and 2’-acrylamidoethyl-β-D-galactopyranoside, in the pyranose form were synthesized. The corresponding glycopolymer brushes were prepd. on silicon substrates by surface-initiated atom transfer radical polymn. (SI-ATRP) using unprotected glycomonomers. The formation of glycopolymer brushes was well-characterized using ellipsometry, ATR-FTIR, water contact angle anal., at. force microscopy anal., and XPS. The effects of halogen, ligand, and solvent on the polymn. were thoroughly investigated. It was shown that CuCl/CuCl2/tris(2-dimethylaminoethyl)amine (Me6TREN) catalytic system with an optimized ratio of Cu(I)/Cu(II) produced glycopolymer with high mol. wt. (Mn = 44-140 kDa) and relatively narrow mol. wt. distribution (PDI = 1.4). The dry thickness of resulting glycopolymer brushes (10-36 nm) showed a proportional relationship with the mol. wt. of free polymer generated in the soln. The grafting densities of obtained glycopolymer brushes were between 0.12 and 0.17 chains/nm2. The grafting of glycopolymer resulted in highly hydrophilic surface layer with very low water contact angles (< 10°). The glycopolymer brushes showed ultralow protein adsorption from bovine serum albumin (BSA) and fibrinogen (Fb) solns. Glycopolymer brushes contg. glucose units showed relatively better protection against BSA and Fb adsorption than those brushes contg. mannose and galactose units. Synthesized glycopolymer brushes retained specific protein interactions, as evident from the interaction with Con A (Con A). The interaction of surface-grafted glycopolymer brushes with Con A depended on both the stereochem. of carbohydrate units and the chem. structures present. In addn., the newly synthesized glycopolymer brushes performed significantly better in comparison with currently available structures in terms of specific protein interactions. [on SciFinder(R)]