Emergent Properties of Giant Vesicles Formed by a Polymerization-Induced Self-Assembly (PISA) Reaction

Abstract

Giant micrometer sized vesicles are of obvious interest to the natural sciences as well as engineering, having potential application in fields ranging from drug delivery to synthetic biology. Their formation often requires elaborate experimental techniques and attempts to obtain giant vesicles from chemical media in a one-pot fashion have so far led to much smaller nanoscale structures. Here we show that a tailored medium undergoing controlled radical polymerization is capable of forming giant polymer vesicles. Using a protocol which allows for an aqueous reaction under mild conditions, we observe the macroscale consequences of amphiphilic polymer synthesis and the resulting molecular self-assembly using fluorescence microscopy. The polymerization process is photoinitiated by blue light granting complete control of the reaction, including on the microscope stage. The self-assembly process leads to giant vesicles with radii larger than 10 microns, exhibiting several emergent properties, including periodic growth and collapse as well as phototaxis.

Direct Synthesis of Polymer Vesicles on the Hundred‐Nanometer‐and‐Beyond Scale Using Chemical Oscillations

“…Recently Albertsen et al. observed the macromolecular self‐assembly of an amphiphilic block copolymer under visible light controlled PISA leading to micron sized vesicles …”

“…[12][13][14] RecentlyA lbertsen et al observed the macromolecular self-assemblyo fa na mphiphilic block copolymer under visible light controlled PISA leadingt om icron sized vesicles. [3] Here, we report self-assembly and self-organizationo fn anometer-sized polymer nanoaggregates at room temperature in the absence of light through RAFT aqueous dispersion polymerization.I nstead of using ap hoto-or thermo-initiator as normal in radical polymerization, we use radicals from the Belousov-Zhabotinsky (B-Z) reaction in oscillatory mode. B-Z is the most studied oscillatory redoxc hemical reaction.…”

“…The self-assembly of block copolymersi na queous environments is important for many differenta pplicationss uch as nanomedicine, [1] nanoreactors, [2] and mimicking some features of life. [3] After polymer synthesis, the typical self-assembly of block copolymers into collective structures is achieved by dissolving one block in af avourables olvent,e nabling reorganization of the other block to form some desirable morphology. [4][5][6][7] The only variable in thesem ethods is the solventp roperties as the blockc opolymer used has af ixed molecular weighta nd a fixed diblock composition.…”

Polymerization‐Induced Self‐Assembly for Artificial Biology: Opportunities and Challenges

“…This gave clues about the formation of membranes and compartments as well as protocells. More strikingly, continuous in situ photo‐irradiation was seen to lead to episodes of cyclic growth and collapse of the vesicles with release of unconsumed macroCTA to the external environment from which new vesicles are generated, a so‐called “Phoenix” behavior (Figure C,D) . The time evolution of vesicle size during the Phoenix episodes showed a typical logistic growth pattern, which carries information on the vesicle formation mechanism and the causes for their individual behavior as members of a population.…”

“…D) Profile of the time evolution during a “phoenix” episode of polymersome diameter evolution (sharing a common progenitor) shows a cyclic growth and collapse behavior when exposed to blue light. The different polymersomes were tracked and their area was measured using a computer algorithm, and their “phoenix” oscillations span ≈3000 s. Reproduced with permission . Copyright 2017, Nature Scientific Group.…”