Alkaline chitosan solutions.

Area of Science:

• Materials Science
• Biopolymer Chemistry

Background:

• Chitosan, a biopolymer derived from chitin, possesses unique properties making it suitable for various applications.
• Developing efficient methods for chitosan processing and modification is crucial for unlocking its full potential.
• Controlling chitosan's properties, such as cationicity and solubility, is key for advanced material fabrication.

Purpose of the Study:

• To develop a novel method for preparing chitosan and chitosan-alginate microspheres.
• To investigate the role of ammonium hydrogen carbonate in modifying chitosan properties.
• To explore the potential of spray-drying for creating chitosan-based microparticles.

Main Methods:

• Chitosan salts were treated with ammonium hydrogen carbonate to form chitosan carbamate ammonium salt.
• Regenerated chitosan solutions were spray-dried to form microspheres.
• Chitosan's cationicity was reversibly masked to enable mixing with alginate.
• Chitosan-alginate mixtures were spray-dried to produce composite microspheres.

Main Results:

• Rigid and transparent chitosan hydrogels were formed.
• Chitosan microspheres with varying crystallinity were produced via spray-drying.
• Citrate cross-linking enhanced microsphere insolubility, while chloride yielded free amine chitosan microspheres.
• Reversible masking of chitosan's cationicity allowed for stable chitosan-alginate solutions.
• Chitosan-alginate microspheres with an average diameter of approximately 2 microns were successfully manufactured.

Conclusions:

• Ammonium hydrogen carbonate treatment offers a versatile route for chitosan processing.
• Spray-drying is an effective technique for producing chitosan and chitosan-alginate microspheres.
• The ability to mask chitosan's cationicity opens avenues for creating novel composite biomaterials.