Novel hydrogel obtained by chitosan and dextrin-VA co-polymerization

Centro de Engenharia Biológica, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
Biotechnology Letters (Impact Factor: 1.59). 09/2006; 28(16):1279-84. DOI: 10.1007/s10529-006-9087-6
Source: PubMed


A novel hydrogel was obtained by reticulation of chitosan with dextrin enzymatically linked to vinyl acrylate (dextrin-VA), without cross-linking agents. The hydrogel had a solid-like behaviour with G' (storage modulus) > G'' (loss modulus). Glucose diffusion coefficients of 3.9 x 10(-6) +/- 1.3 x 10(-6) cm(2)/s and 2.9 x 10(-6) +/- 0.5 x 10(-6) cm(2)/s were obtained for different substitution degrees of the dextrin-VA (20% and 70% respectively). SEM observation revealed a porous structure, with pores ranging from 50 microm to 150 microm.

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    ABSTRACT: a b s t r a c t New dextrin hydrogels with degrees of substitution (DS) from ca. 10% (DS 10) to 70% (DS 70) were pre-pared by radical polymerization of aqueous solutions of vinylacrylate (VA)-derivatized dextrin. A preli-minary analysis on the potential of these hydrogels for the controlled release of bioactive molecules was carried out. The protein (bovine serum albumin) diffusion coefficients on the hydrogels were calcu-lated using the lag-time analysis. Values in range 10 À7 cm 2 /s were obtained for DS 20 and DS 40 and a smaller value of 10 À8 cm 2 /s arised upon DS increasing to 70%, revealing the dependence of the diffusivity on the crosslinking density. The release of BSA from dextrin-VA hydrogels, in the presence of amyloglu-cosidase was shown to be mainly dependent on the diffusion and, to a smaller extent, on the degradation kinetics. The protein release can be tailored from days to months by varying the DS.
    Carbohydrate Polymers 09/2008; 75(2). DOI:10.1016/j.carbpol.2008.07.033 · 4.07 Impact Factor
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