Preparation and characterization of water-soluble chitin and chitosan derivatives

Chitosan was modified with poly(ethylene glycol)-aldehyde (PEG-aldehyde) of various molecular weights under the various molar ratios of PEG-aldehyde to chitosan. Then the prepared chitosan-PEG hybrid was converted to chitin-PEG hybrid by the acetylation with acetic anhydride. The solubility of various derivatives was investigated in three buffers of various pH. Some of these derivatives were soluble in 0.01 M phosphate buffer saline (PBS, pH = 7.2). The solubility in PBS was dependent on the degree of PEG substitution, the degree of acetylation, the molecular weight of PEG, and the weight ratio of PEG in chitin/chitosan-PEG hybrid.