DNA-Mediated Step-Growth Polymerization of Bottlebrush Macromonomers

Abstract

Herein, we report the DNA-mediated self-assembly of bivalent bottlebrush polymers, a process akin to the step-growth polymerization of small molecule monomers. In these “condensation reactions”, the polymer serves as a steric guide to limit DNA hybridization in a fixed direction, while the DNA serves as a functional group equivalent, connecting complementary brushes to form well-defined, one-dimensional nanostructures. The polymerization was studied using spectroscopy, microscopy, and scattering techniques and was modeled numerically. The model made predictions of the degree of polymerization and size distribution of the assembled products, and suggested the potential for branching at hybridization junctions, all of which were confirmed experimentally. This study serves as a theoretical basis for the polymer-assembly approach which has the potential to open up new possibilities for suprapolymers with controlled architecture, macromonomer sequence, and end-group functionalities.

Functional DNA–Polymer Conjugates

“…Second, the number of DNA strands at one termini is critical to avoid multiple connections on one block. Their further studies also investigated the self-assembly kinetics and provided a model to accurately predict the degree of polymerization and size distribution of the assembled products . Moreover, in order to improve the biopharmaceutical properties of ODN therapeutics, in another example, they developed a DNA-backboned bottlebrush structure with PEG side chains (Figure C) .…”

“…Their further studies also investigated the self-assembly kinetics and provided a model to accurately predict the degree of polymerization and size distribution of the assembled products. 185 Moreover, in order to improve the biopharmaceutical properties of ODN therapeutics, in another example, they developed a DNA-backboned bottlebrush structure with PEG side chains (Figure 18C). 186 Here, the PEGylated ODN hairpins were constructed to realize a hybridization chain reaction, which lead to a living polymerization using two hairpins as monomers.…”

Molecular polymer bottlebrushes in nanomedicine: therapeutic and diagnostic applications

“…Initially, the Zhang group made PEG MPBs containing hairpin DNA on either end. 116,117 This allowed the MPB end-tips to hybridise at elevated temperatures, which led to a polycondensation of PEG MPBs. This strategy was then used to produce PEG MPB-DNA conjugates with only one DNA strand (10 or 15 mer) on one end of the MPB.…”

Synthetic approaches for copolymers containing nucleic acids and analogues: challenges and opportunities

“…Our group has routinely used this reaction to conjugate a variety of dibenzocyclooctyne (DBCO)-modified nucleic acids and analogues to azide-derivatized polymers, even hydrophobic ones, 33,34 often with nearquantitative yields. [35][36][37][38][39] One challenge associated with bioconjugation is the removal of unreacted polymers and nucleic acids. Mirkin and co-workers circumvented this difficulty by performing the conjugation reaction on a solid support.…”