DNA-Grafted Polypeptide Molecular Bottlebrush Prepared via Ring-Opening Polymerization and Click Chemistry

A new type of DNA grafted polypeptide molecular brush was synthesized via a combination of ring-opening polymerization (ROP) and click chemistry. This conjugation method provides an easy and efficient approach to obtain a hybrid DNA-grafted polypeptide molecular bottlebrush. The structure and assembly behaviors of this hybrid brush were investigated using electrophoresis, UV-vis spectroscopy, transmission electron microscopy (TEM), and atomic force microscopy (AFM). Hierarchical supramolecular assemblies can be obtained through hybridization of two kinds of polypeptide-g-DNA molecular bottlebrushes containing complementary DNA side chains. We further demonstrated that such polypeptide-g-DNA can be hybridized with ds-DNA and DNA-grafted gold nanoparticles to form a supermolecular bottlebrush and hybrid bottlebrush, respectively. In addition, DNA-polypeptide hydrogel can be prepared by hybridization of polypeptide-g-DNA with a linker-ds-DNA, which contains the complementary "sticky ends" to serve as cross-linkers.