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作者： Jinjie Lu,   Feng Zhou,   Lishan Li,   Zhengbiao Zhang,   Fenghua Meng,   Nianchen Zhou, and    Xiulin Zhu

State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, P. R. China

 

摘要：A cyclic azobenzene was chosen as a pendant in the hydrophobic segments of amphiphilic copolymers, and novel nanoparticles were constructed with dual photo and reductant responsiveness. To investigate the topological effects of the cyclic azobenzene architecture on the properties, an analogue of the amphiphilic copolymer with linear azobenzene units was also synthesized. Two kinds of amphiphilic copolymers with cyclic azobenzene (PEG45-b-PCAzo17) and linear azobenzene pendants (PEG45-b-PLAzo19) assembled into stable vesicles in PB solution (pH = 7.4) and also show unique dual sensitivities to ultraviolet radiation and dithionate derivatives. We have investigated the differences of the vesicles obtained from the two kinds of copolymers in the encapsulation and release of Nile Red (NR) or doxorubicin (DOX). The vesicles formed by PEG45-b-PCAzo17 exhibited higher drug loading content and better reversibility of NR fluorescence variation under alternating irradiation with UV/Vis light than those formed by PEG45-b-PLAzo19; meanwhile, neither disruption of the vesicles nor leakage of Nile Red molecules was detected. Moreover, the CAzo-containing vesicles showed a higher release rate and larger release amount of DOX molecules from the membrane under the reduction of Na2S2O4. Because dithionites can act as a mimic of azoreductase, the amphiphilic copolymer with cyclic azobenzene revealed competitive performance as a drug carrier for colon disease treatment.