Photopatterning and Degradation Study of Dextran-Glycidyl Methacrylate Hydrogels*

An approach to synthesizing photopatternable enzymatic degradable dextran hydrogel is presented. The glycidyl methacrylate derivatized dextran (Dex-GMA) was first prepared by reacting dextran with glycidyl methacrylate at 458C with grafting efficiency of 10%. The degree of substitution (DS) was confirmed by H-NMR. Next, Dex-GMA hydrogels were prepared by crosslinking in the presence of a crosslinker: N,N0methylene-bisacrylamide (NMBA), and a photoinitiator: 2,20-dimethoxy-2-phenyl acetophenone (DMPA) in dimethyl sulfoxide (DMSO) solution. Further, the DexGMA hydrogels were photopatterned using liquidphase photopolymerization (LP) technique. The structure size ranged from 5 mm to 300 lm and three different shapes of structures--—round, square, and star--—were demonstrated. The patterned Dex-GMA hydrogel structures not only exhibited mechanical robustness but also biodegradability. The dextranasecatalyzed degradation of Dex-GMA hydrogels with different DS was investigated at 378C. The morphology of the degraded Dex-GMA hydrogels determined by SEM revealed the degree of enzymatic degradation due to dextranase. The Dex-GMA hydrogel was fully degraded by dextranase with concentration of 2 U/ml in 5 days. The Dex-GMA hydrogel also showed the ability to be readily integrated with microfluidics. POLYM. ENG. SCI., 50:232–239, 2010. a 2009 Society of Plastics Engineers