Enzyme‐PISA: An Efficient Method for Preparing Well‐Defined Polymer Nano‐Objects under Mild Conditions

Abstract

Enzyme catalysis is a mild, efficient, and selective technique that has many applications in organic synthesis as well as polymer synthesis. Here, a novel enzyme-catalysis-induced reversible addition-fragmentation chain transfer (RAFT)-mediated dispersion polymerization for preparing AB diblock copolymer nano-objects with complex morphologies at room temperature is described. Taking advantage of the room-temperature feature, it is shown that pure, worm-like polymer nano-objects can be readily prepared by just monitoring the viscosity. Moreover, it is demonstrated that inorganic nanoparticles and proteins can be loaded in situ into vesicles by this method. Finally, a novel oxygen-tolerant RAFT-mediated dispersion polymerization initiated by enzyme cascade reaction that can be carried out in open vessels is developed. The enzyme-initiated RAFT dispersion polymerization provides a facile platform for the synthesis of various functional polymer nano-objects under mild conditions.

New Insights into RAFT Dispersion Polymerization‐Induced Self‐Assembly: From Monomer Library, Morphological Control, and Stability to Driving Forces

“…More recently, HPMA‐based PISA formulations with oxygen tolerance assisted by enzyme deoxygenation have also been reported . Furthermore, the same group reported an aqueous RAFT PISA of HPMA initiated by enzyme catalysis at room temperature . Glucose oxidase–horseradish peroxidase (GOx‐HRP) cascade reaction was utilized for both deoxygenation and initiation .…”

“…Furthermore, the same group reported an aqueous RAFT PISA of HPMA initiated by enzyme catalysis at room temperature . Glucose oxidase–horseradish peroxidase (GOx‐HRP) cascade reaction was utilized for both deoxygenation and initiation . O'Reilly group reported in situ encapsulation of proteins in PEG‐PHPMA vesicles via a mild one‐pot aqueous initiator‐free photo‐PISA approach .…”

PISA: construction of self-organized and self-assembled functional vesicular structures

“…Aqueous dispersion polymerization of HPMA from a PEG trithiocarbonate CTA produced BCP objects ranging from spheres to vesicles. 76 This method could be used to load protein molecules into the vesicles in situ, utilizing the mild conditions under which PISA was conducted. Belousov-Zhabotinsky (BZ) redox oscillatory reactions have also been employed to initiate RAFT-PISA at room temperature, by the polymerization of butyl acrylate and acrylonitrile monomers from PEG-based mCTAs in the aqueous BZ reaction media.…”

Ketone‐Functionalized Polymer Nano‐Objects Prepared via Photoinitiated Polymerization‐Induced Self‐Assembly (Photo‐PISA) Using a Poly(diacetone acrylamide)‐Based Macro‐RAFT Agent

“…Over the past ten years or so, the development of polymerization‐induced self‐assembly (PISA) by Pan and co‐workers, Armes and co‐workers, Charleux et al, and others enables well‐defined block copolymer nano‐objects with different morphologies to be prepared at high solids contents (up to 50% w/w) without further processing. In particular, PISA based on reversible addition–fragmentation chain transfer (RAFT)‐mediated dispersion polymerization is an attractive strategy that can be carried out in either polar or nonpolar solvents using a wide range of core‐forming monomers and macromolecular RAFT (macro‐RAFT) agents .…”