Confinement of proteins by thermoresponsive dendronized polymers

Abstract

The crowding environment created by host polymers plays crucial roles in manipulating interactions with proteins and modulating their bioactivity. Here, we report our investigation on the interactions between polymers and proteins in the confined microenvironments constructed by oligoethylene glycol (OEG)-based dendronized polymers due to the crowded OEG dendrons. Several important characteristics of these dendronized polymers, including their aggregation state, charge state and combination form with biomolecules, were revealed to be the main factors decoding the polymer–protein interactions. To examine the effects of encapsulation and shielding from the dendronized polymers for the biomacromolecules, the guest proteins were combined through either bioconjugation, electrostatic complexation, or just physical mixing. The unprecedented thermoresponsiveness of the dendronized polymers provides tunable crowding and hydrophobicity of the microenvironment conveniently through their thermally induced aggregation, resulting in regulation of the activities for the proteins. This kind of dendronized polymer with structural and topological features is a promising candidate for the construction of intelligent artificial microenvironments to tunably confine biomacromolecules.