Starch-chitosan hydrogels prepared by reductive alkylation cross-linking

J Mater Sci Mater Med. 2004 Jul;15(7):759-65. doi: 10.1023/b:jmsm.0000032815.86972.5e.

Abstract

Starch-chitosan hydrogels were produced by oxidation of soluble starch to produce polyaldehyde and subsequently cross-linked with chitosan via reductive alkylation. The swelling ratio of starch-chitosan membranes was increased gradually with increasing starch ratio, but it was always lower than the native chitosan. In dry state, starch-chitosan membranes with low starch ratio (0.16, 0.38) showed similar tensile strength values to those of native chitosan while these values decreased with increasing starch ratios (0.73-1.36). Membranes in physiological buffer solution (PBS) gave a tensile modulus between 2.8 and 1.0 MPa, decreasing with increasing starch ratio (0.16-1.36 (Wstarch/Wchitosan)). When the membranes were incubated in PBS only, a moderate weight loss was observed for the first two weeks. Original weights of low starch weight ratio membranes (0-0.38) were at near 85%, while high ratio samples (0.73-1.55) were kept around 70% after three months. However, for the membranes incubated in alpha-amylase solution, very fast weight loss was observed. For low starch ratio membranes (0.16, 0.38, 0.73), the residual original weights were measured to be 11%, 6%, 20%, while for high ratio membranes (1.04 and 1.36) these were 45% and 30%, respectively, after two months of enzyme incubation. Scanning electron microscopy analysis of alpha-amylase degraded membranes exhibited rough surface morphology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkylation
  • Chitosan*
  • Cross-Linking Reagents
  • Hydrogels*
  • Materials Testing
  • Microscopy, Electron, Scanning
  • Oxidation-Reduction
  • Starch*
  • Tensile Strength

Substances

  • Cross-Linking Reagents
  • Hydrogels
  • Starch
  • Chitosan