Synthesis of an O-alkynyl-chitosan and its chemoselective conjugation with a PEG-like amino-azide through click chemistry

► Conjugation of an amino-alkyne moiety to N-phthaloyl chitosan's C6 hydroxyls, after pre-activation with N,N′-carbonyldiimidazole (CDI). ► Chemoselective azide-alkyne conjugation between the alkynylated polymer and a commercial PEG-like azide. ► Removal of the amine-protecting phthaloyl group to yield back chitosan's original primary amines, responsible for chitosan's bioadhesive and tissue-regenerating properties. ► Full characterization of starting, intermediate and final polymers by a toolbox of techniques, including FT-IR, SS-NMR and XPS.