CO₂‐Activated Reversible Transition between Polymersomes and Micelles with AIE Fluorescence

Abstract

Fluorescent polymersomes with both aggregationinduced emission (AIE) and CO 2 -responsive properties were developed from amphiphilic block copolymer PEG-b-P(DEAEMA-co-TPEMA) in whicht he hydrophobic block was ac opolymer made of tetraphenylethene functionalized methacrylate (TPEMA) and 2-(diethylamino)ethyl methacrylate (DEAEMA) with unspecified sequence arrangement. Four blockc opolymers with different DEAEMA/TPEMA and hydrophilic/hydrophobic ratios were synthesized, and bright AIE polymersomes were prepared by nanoprecipitation in THF/water and dioxane/water systems.P olymersomes of PEG 45 -b-P(DEAEMA 36 -co-TPEMA 6 )w ere chosen to study the CO 2 -responsive property.U pon CO 2 bubbling vesicles transformed to small spherical micelles,and upon Ar bubbling micelles returned to vesicles with the presence of af ew intermediate morphologies.T hese polymersomes might have promising applications as sensors,nanoreactors,orc ontrolled release systems.

Precise and Controllable Assembly of Block Copolymers†

“…[ 1‐4 ] This bottom‐up synthesis of micellar nanostructures has encouraged the applications of BCP micelles in many fields, such as bio‐drug cargo and delivery, [ 5‐6 ] nanoreactors, [ 7 ] hierarchical nanocomposites, [ 8‐9 ] and stimuli‐responsive materials. [ 10 ] The micelles can be mainly divided into two categories according to the core‐ and corona‐forming block length: “star‐like” micelles or hairy micelles with thick coronal layer and relatively small core; and “crew‐cut” micelles with a thin coronal layer and relatively big core. [ 11 ] Compared with the “star‐like” micelles, the morphological variations of the “crew‐cut” micelles were more abundant.…”

Polymersomes with Red/Near‐Infrared Emission and Reactive Oxygen Species Generation

“…[19,44] Compared to liposomes, polymersomes composed of amphiphilic block copolymers have thicker membranes and consequently present greatly increased chemical stability, lower membrane permeability, and higher mechanical robustness. [45][46][47][48][49][50] Moreover, the size of polymersomes can be tuned by different strategies [51][52][53][54] to fall within 50 and 200 nm, the "ideal size" of carriers for intravenous drug delivery. [55][56][57] The recent development of polymer chemistry enables almost unlimited molecular design of functional amphiphilic copolymers that can be used to prepare polymersomes with various applications such as nano-and micro-reactors, [58][59] cell membrane models, [60] and drug delivery systems.…”

Restriction of Conformation Transformation in Excited State: An Aggregation-Induced Emission Building Block Based on Stable Exocyclic C=N Group

“…Generally, the luminogens with AIE characteristic (AIEgens) are weak fluorescent or non-fluorescent in solution state, but emit intense fluorescence when they aggregate in solid state, which is different from the traditional organic emitters with excellent photoluminescence (PL) performance in dispersive state rather than in aggregates. Based on these remarkable advantages, AIEgens are widely applied to various fields depending on aggregate luminescence, such as organic light-emitting diodes (OLEDs) and organic nano-dots for bio-imaging ( Wei et al., 2018a ; Hu et al., 2018 ; Feng and Liu, 2018 ; Kwok et al., 2015 ; Zhang et al., 2019 ; Qian and Tang, 2017 ).…”