Carboxylmethyl chitosan-graft-poly(γ-benzyl-l-glutamate) glycopeptides: Synthesis and particle formation as encapsulants

Amphiphilic glycopeptides, carboxylmethyl chitosan-graft-poly(γ-benzyl-l-glutamate) (m-Chi-g-PBLG), were synthesized through ring-opening polymerization of γ-benzyl-l-glutamate N-carboxyanhydride (NCA) using short chained m-Chi as the macroinitiator and employed to form vesicles in aqueous solution. The elemental and NMR analyses revealed that the polymerization degree (DP) of grafted PBLG could be tuned by varying the feed ratio of NCA to m-Chi. The conformation of the grafted PBLG chains transformed from β-sheet to α-helix was correlated with the PBLG chain length. The m-Chi-g-PBLG vesicles can be prepared using double emulsion method and their sizes can be adjusted between 140 and 250 nm. The encapsulation of a model compound, FITC-dextran, in the vesicles revealed their potential applications as encapsulants or carriers. The in vitro release data revealed that a sustained release of FITC-dextran for a time period over two weeks can be achieved.