Preparation and characterization of chitosan membranes by using a combined freeze gelation and mild crosslinking method

作者：Orrego Carlos E^*; Valencia Jesus S

来源：Bioprocess and Biosystems Engineering, 2009, 32(2): 197-206.

DOI：10.1007/s00449-008-0237-1

• Chitosan
• Cryogel
• Surface properties
• Immobilized lipase

When gelification is performed by freezing-thawing repeated cycles, the resultant gel-like polymer systems are called cryogels. This work aims to assess the effect of the addition of glutaraldehyde and 18 Crown Ether-6 on surface properties and protein loading of dried chitosan cryogel films. Residual water content of treated chitosan membranes ranged between 11.93 and 13.86%, while their water activities vary from 0.5 to 0.7 (measured from 4 to 60 A degrees C). Based on thermal data, water evaporation peak and degradation temperatures of chitosan membranes shifted to a higher temperature for crosslinked samples. X-ray diffractograms provide high values of crystallinity for all the samples (70.67-92.86%), the highest value being for the glutaraldehyde-treated membrane. Candida rugosa lipase can be immobilized successfully on chitosan membranes. Lipase immobilized on glutaraldehyde-crosslinked chitosan yielded the highest efficiency in terms of total coupled protein and protein loading efficiency.

• 出版日期2009-2