Polymersomes from Hybrid Peptide-Based Bottlebrush Homopolymers

A series of compounds, in which exo-norbornene scaffold appended with amino acids, was synthesized. These compounds underwent ring opening metathesis polymerization (ROMP) catalyzed by Grubbs second generation ruthenium catalyst to form polymers with bottlebrush architecture. Four different polymers P1-P4 were synthesized, differing in number of lipid units and degree of branching. These polymers were well-characterized by 1H NMR and gel permeation chromatographic (GPC) techniques. These peptide-based homopolymers showed an exceptional ability to self-assemble to form polymersomes. The self-assembled structures were characterized by various ultramicroscopic techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The entrapment capability of polymer vesicles was confirmed by dye-encapsulation studies.