A NEW CLASS OF POLYMERIZABLE DEXTRANS WITH HYDROLYZABLE GROUPS - HYDROXYETHYL METHACRYLATED DEXTRAN WITH AND WITHOUT OLIGOLACTATE SPACER

In this paper a synthetic procedure is described towards a new class o f methacrylated dextrans which are sensitive to hydrolysis. These meth acrylated dextrans, which can be used for the development of biodegrad able hydrogels, were obtained by grafting L-lactide onto 2-hydroxyethy l methacrylate (HEMA), followed by activation of the terminal hydroxyl group with N,N'-carbonyldiimidazole (CDI), yielding HEMA-lactateCI. C oupling of this compound to dextran in dimethyl sulfoxide in the prese nce of dimethylaminopyridine resulted in dexlactateHEMA. In the same w ay, dex-HEMA was obtained by coupling of CDI-activated HEMA to dextran . The degree of substitution, as determined by H-1-NMR, could be contr olled by Varying the molar ratio of HEMA-CI or HEMA-lactateCI to dextr an. The incorporation efficiency was 60-85%. The dextran derivatives w ere obtained in high yield (85-90%) and characterized by NMR, FTIR and GPC. (C) 1997 Elsevier Science Ltd.