Introduction
Chitosan, the cationic (1-4)-2-amino-2-deoxy--d-glucanpartly acetylated to the typical extent close to 0.20, is industriallyproduced from marine chitin, the linear (1-4)-2-acetamido-2-deoxy--d-glucan. Both of them have attracted attention owingto their superior characteristic properties, among which biocom-patibility and absence of toxicity