Abstract:

Chitosan is an important biomedical material, and its degree of deacetylation is a main
parameter of its biodegradation. Gel permeation chromatography was used to investigate the lysozymic
degradation of two types of chitosan samples (A and B) with similar degree of deacetylation and
relative molecular mass but with different distributions of two units of N-acetyl-D-glucosamine and
D-glucosamine. Weight average relative molecular mass, polydispersity and gel permeation
chromatograms during the degradation process were obtained. It was found that chitosan sample A with
random distribution of the two units underwent a homogeneous degradation process while chitosan
sample B with block distribution underwent a heterogeneous degradation process. The results suggest
that the homogeneity of the degradation of chitosan materials by lysozyme depends on the
distribution type of the two units, which can help to design chitosan-based biomedical devices.

Key words: chitosan, degradation, homogeneity , lysozyme, gel permeation chromatography