Chitosan is a basic linear polysaccharide containing β-[1→4]-linked 2-acetamido-2-deoxy-D-glucopyranose and 2-amino-2-deoxy-D-glucopyranose units. Because of the presence of reactive amino groups, chitosan can be modified easily to create nano- and micro particulate systems, films or porous hydrogels. The present investigation describes the synthesis and characterization of novel biodegradable nanoparticles based on chitosan with conjugated fluorescent moiety for biomedical applications. Chitosan and its cross-linked derivatives were used as carrier for fluorescein isothiocyanate molecules. Cross-linked chitosan nanoparticles were prepared by covalently modification via amino groups of the chitosan chain in aqueous media at room temperature. Natural di- and tricarboxylic acids were used for intramolecular cross-linking of the chitosan linear chains. The condensation reaction of carboxylic groups and pendant amino groups of chitosan was performed by using water soluble carbodiimide. This method allows the formation of polycations, polyanions and polyampholyte nanoparticles. The solubility, structure and size of these nanoparticles in the dried and swelled states will be described and discussed. The cross-linked chitosan nanoparticles may dissolve and form stable colloid systems in aqueous media at low pH, neutral and mild alkaline conditions. Because they are nano-sized at neutral pH, they can be attractive candidate delivery biosystems for a variety of biomedical applications.
Journal: TechConnect Briefs
Volume: 2, Technical Proceedings of the 2007 NSTI Nanotechnology Conference and Trade Show, Volume 2
Published: May 20, 2007
Pages: 279 - 282
Industry sectors: Advanced Materials & Manufacturing | Medical & Biotech
Topics: Biomaterials, Materials Characterization & Imaging