Synthesis and characterization of acrylic acid-containing dextran hydrogels

pH-Sensitive dextran hydrogels were prepared by free radical polymerization of methacrylate derivatized dextran, acrylic acid and N-t-butylacrylamide. Incorporation of acrylic acid in hydrogels was confirmed by Fourier transform infrared spectroscopy. The pH-dependent swelling of hydrogels was strongly influenced by the acrylic acid content, conjugation degree of methacrylate moiety with dextran and modified dextran concentration. Intermolecular polymerization that occurred to a greater extent with a lower degree of conjugation of methacrylate and/or higher concentration of modified dextran effectively increased the network density of hydrogels. An increase of acrylic acid reduced the enzymatic degradability of pre-swollen hydrogels by dextranase, although the increased equilibrium swelling was observed.