Design and synthesis of multifunctional chitosan from water-based reaction system for potentially biomedical materials

Abstract

The present work focuses on molecular design, synthesis, systematic studying of multifunctional chitosan to use as promising biomedical materials. Here, the strategies of nanoparticle self assembly and hybridization of chitosan-inorganic nanoparticle are proposed to produce multifunctional. chitosan. However, the use of chitosan without acidic solvent is still required. Thus, the multifunctional chitosan from 2 strategies are prepared by chemical functionalization based on water-based reaction system and mild condition. In the first part. biomolecules, phenylalanine and polyethylene glycol, are derivatized on chitosan chain via CS-HOBt water soluble system and conjugating reaction. This chitosan derivative shows the colloidal stability in water, nanoparticle forming, and ability to form allergen. This design system is proposed to use in allergen delivery system. In the second part, chitosan is functionalized with active molecule called as oxanorbornadiene. The chitosan-oxanorbornadiene is proposed as a novel type of chitosan derivative which can be further coupled with azido-modified substrates to provide various types of functional groups on chitosan chain via Cu-free Click. The reaction can be done in aqueous solution without catalyst and purification steps. In the final part. chitosan-oxanorbornadiene is developed to be a water-soluble chitosan derivative to hybridize with inorganic nanoparticles, azido-gold nanoparticles. The success of hybridization provides the gold aggregation via Cu-free Click. This part is extended to use this chitosan-oxanorbornadiene as a linker between gold nanoparticles and antigens to provide the gold aggregated acceleration in naked-eye detection of antigens.