Synthesis and characterization of biodegradable hydrophobic-hydrophilic hydrogel networks with a controlled swelling property

A biodegradable polymer network hydrogel system with both hydrophilic and h ydrophobic components was synthesized and characterized. The hydrophilic an d hydrophobic components were dextran and poly(D,L)lactic acid (PDLLA), res pectively. These two polymers were chemically modified for incorporating un saturated groups for subsequent UV crosslinking to generate a hydrogel with a three-dimensional network structure. The effects of the reaction conditi ons on the synthesis of a dextran derivative of allyl isocyanate (dex-AI) w ere studied. All newly synthesized materials were characterized by Fourier transform infrared and NMR. The swelling property of the hydrogels was stud ied in buffer solutions of different pHs. The results of this study showed that a wide-range swelling property was obtained by changes in the dex-AI/P DLLA composition ratio, the type and degree of unsaturated groups incorpora ted into dextran, and the UV photocrosslinking time. The solvent extraction effect on the swelling property of the hydrogels was also studied. (C) 200 0 John Wiley & Sons, Inc.