Chitosan N-sulfate. A water-soluble polyelectrolyte

Area of Science:

• Biochemistry
• Polymer Science
• Materials Science

Background:

• Chitosan, a polysaccharide derived from chitin, possesses unique properties but often exhibits limited water solubility.
• Modifying chitosan's chemical structure can enhance its solubility and introduce new functionalities for various applications.

Purpose of the Study:

• To synthesize N-sulfated chitosan derivatives with varying degrees of acetylation (da) and sulfation (ds).
• To investigate the impact of da and ds on the solubility and rheological properties of these derivatives.
• To explore the interactions of N-sulfated chitosan derivatives with other polyelectrolytes.

Main Methods:

• N-sulfation of chitosans with different da (0.04, 0.10, 0.22) under varied reaction conditions.
• Characterization of N-sulfated chitosan derivatives for their degree of sulfation (ds), ranging from 0.4 to 0.86.
• Assessment of solubility in water and rheological properties of the derivative solutions.
• Evaluation of interactions with O-(carboxymethyl)cellulose, xanthan gum, and heparin under varying ionic strength and pH.

Main Results:

• All synthesized N-sulfated chitosan derivatives were soluble in water.
• The rheological properties of the solutions were significantly influenced by both da and ds values.
• Solubility and interactions with other polyelectrolytes were affected by pH and ionic strength.
• Chitosan derivatives demonstrated compatibility with O-(carboxymethyl)cellulose, xanthan gum, and heparin.

Conclusions:

• N-sulfation is an effective method to produce water-soluble chitosan derivatives.
• The degree of acetylation and sulfation critically control the physicochemical properties of these derivatives.
• The compatibility of N-sulfated chitosan derivatives with other polyelectrolytes suggests their utility in diverse aqueous formulations.