Rapidly SO2-responsive vesicles with intrinsic fluorescent indicators for membrane structure evolution

Stimuli-responsive vesicles (SRVs) have been widely exploited as smart nanocarriers for biomedical applications. Herein, high-performance SO2 -responsive nanovesicles were reported to exemplify a new mode of SRVs. Structurally, the sensory vesicles were based on amphiphilic hydrogen-bonded (HB) polymers which can be facilely fabricated via modular self-assembly. The HB polymers are designed to consist of a melamine-barbituric acid HB skeleton with pendant anthracene fluorophores and amphiphilic side chains. Upon stimulation with increasing amount of SO2, the vesicles in aqueous solution undergo an unusual morphology evolution including rapid fission into small ones, swelling and final collapse of the offspring vesicles. During this process, the intrinsic fluorescence response of the vesicles allows intuitive tracking of the hierarchical structural evolution of the self-assembled membranes and straightforward quantitation of the stimuli. This work exemplifies a rational design of auto-recording stimuli-responsive nanovesicles. (c) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.