Dendron-like Polypeptide/Linear Poly(ethylene oxide) Biohybrids with Both Asymmetrical and Symmetrical Topologies Synthesized via the Combination of Click Chemistry and Ring-Opening Polymerization

Abstract

Dendron-like poly(γ-benzyl-l-glutamate)/linear poly(ethylene oxide) block copolymers with both asymmetrical and symmetrical topologies (i.e., ABn type Dm-PBLG-b-PEO and BnABn type Dm-PBLG-b-PEO-b-Dm-PBLG; n = 2m, m = 0, 1, 2, and 3; Dm are the propargyl focal point poly(amido amine) type dendrons having 2m terminal primary amine groups) were synthesized via the combination of ring-opening polymerization (ROP) of γ-benzyl-l-glutamate N-carboxyanhydride (BLG-NCA) and click chemistry according to the “arm-first” and “core-first” strategies. In the arm-first method, the propargyl focal point dendrons Dm having 2m terminal primary amine groups were first used for initiating the ROP of BLG-NCA, generating “clickable” dendron-like Dm-PBLG homopolymers having 2m branches, which were then click conjugated with azide-terminated PEO (PEO-N3) to produce asymmetrical Dm-PBLG-b-PEO. In the core-first strategy, the propargyl focal point Dm was first click conjugated with PEO-N3 to generate primary amine-terminated PEO d...