“Breathing” CO₂‐, O₂‐, and Light‐Responsive Vesicles from a Triblock Copolymer for Rate‐Tunable Controlled Release

Abstract

group [26] who prepared an O 2 -"breathing" vesicle upon alternately purging with O 2 and Ar. Noteworthy, SRPVs with dual or multiresponsiveness have attracted enormous attention because multiresponsive systems can greatly improve their versatility in a variety of applications. [31][32][33][34] In contrast to lots of contact-triggered stimuli responses, light is a contact-free and environment-friendly stimulus. [35] Therefore, light is one of the most common triggers to realize remote controlled release. [36,37] So far, to the best of our knowledge, combining light responsiveness with CO 2 and O 2 -responsiveness to prepare triple-responsive vesicles has not yet been explored. A further challenge of such a vesicular system, besides the synthetic challenge, is how to maintain its "breathing"-responsive behavior instead of causing a sharp disassembly or a vesicle-tomicelle transition upon external stimuli (CO 2 , O 2 , and light). Usually, apart from cross-linked vesicles, a suitable polymer structure is an efficient strategy to endow SRPVs with a swelling responsive behavior to achieve a tunable membrane permeability. [15,38] In the present work, we report on the first CO 2 -, O 2 -, and lightresponsive vesicles from an amphiphilic triblock copolymer. To fabricate "breathable" vesicles, the work from Feng's group was referred to for the design of suitable chemical structures of triblock copolymers. [38] In this case, poly(N,N-dimethylamino ethyl methacrylate-co-2,2,2-trifluoroethyl methacrylate) (P(DMAEMAco-TFEMA)) with CO 2 and O 2 -responsiveness was chosen as the middle block, and poly(4-(4-methoxy-phenylazo)phenoxy methacrylate) (PMEPPMA) with light responsiveness was chosen as the end block. Due to the rigid structure of PMEPPMA, selfassembled vesicles can exhibit only swollen transitions upon CO 2 and O 2 stimulation, rather than switching to micelles or dissociating into unimers. Based on this suitable chemical structure and stimuli responsiveness, such vesicles present a "breathing" behavior under external stimulation (see Scheme 1), indicating the membrane permeability of such vesicles can be controlled via a single stimulus or various stimuli combinations. Furthermore, using Calcein as a model, it is demonstrated that the vesicles with their altering membrane permeability could serve as potential nanocarriers for an efficient rate-tunable controlled drug release. Results and DiscussionHerein, a CO 2 -, O 2 -, and light-responsive amphiphilic triblock copolymer, poly[(ethylene glycol)methyl ether]-block-poly(N,Ndimethylamino ethyl methacrylate-co-2,2,2-trifluoroethyl

Preparation of quadruple responsive polymeric micelles combining temperature‐, pH‐, redox‐, and UV‐responsive behaviors and its application in controlled release system

“…Although significantly progress has been made in the past decades, artificial stimuli responsive systems are far less sophisticated than natural polymers, that is, proteins that can respond to multi stimuli and changes assembly structures accordingly. Thus, multi‐responsive systems that respond to two or more stimuli have been investigated . For instance, Yang et al .…”

Polymersomes: Breaking the Glass Ceiling?

“…Lin et al developed a triple‐stimuli responsive system: CO 2, light and O 2, using a poly[(ethylene glycol)methyl ether]‐ block ‐poly( N , N ‐dimethylamino ethyl methacrylate‐ co ‐2,2,2‐trifluoroethyl methacrylate)‐ block ‐poly(4‐(4‐methoxy‐phenylazo)phenoxy methacrylate) (PEG‐ b ‐P(DMAEMA‐ co ‐TFEMA)‐ b ‐PMEPPMA) triblock tetrapolymer. The P(DMAEMA‐ co ‐TFEMA) block was responsive to CO 2 and O 2 ( Figure ).…”

“…c) DLS results showing the change in size of vesicles with stimuli. Reproduced with permission . Copyright 2017, Wiley‐VCH.…”

UV-triggered shape-controllable PP fabric

“…On account of this trans to cis transition, azobenzene or its derivatives can switch from unipolar and hydrophobic properties to polar, hydrophobic and nonplanar geometric properties. 13 Based on this unique feature, numerous light-responsive polymeric materials driven by an azobenzene moiety have been explored, such as light-responsive self-assembled aggregates, hydrogels and fibers, surfaces and actuators. [14][15][16][17][18] Among all of them, light-responsive actuators have recently attracted considerable attention due to their light-remote-controllable character.…”