Synthesis of poly(ethylene glycol)-SS-poly(ε-caprolactone)-SS-poly(ethylene glycol) triblock copolymers via end-group conjugation and self-assembly for reductively responsive drug delivery

  • Junbo LiEmail author
  • Junting Jiang
  • Biyu Zhou
  • Chaohuang Niu
  • Wendi Wang
  • Wenlan Wu
Research Article


In this study, we describe a simple synthesis route to prepare triblock copolymers with disulfide-linkers, poly(ethylene glycol)-SS-poly(ε-caprolactone)-SS-poly (ethylene glycol) (PEG-SS-PCL-SS-PEG) for application in the reductively responsive release of doxorubicin (DOX). To synthesize PEG-SS-PCL-SS-PEG, two end-groups of PCL-diol were first modified with cystamine to introduce disulfide bonds and subsequently conjugated with PEG-NHS via carbodiimide chemistry. PEG-SS-PCL-SSPEG fabricated into polymeric micelles with stable structure and different nanoscale sizes via adjusting the PCL chain length, showing obvious reductive responsiveness and fast drug release of encapsulated DOX in the presence of glutathione (GSH). Moreover, DOX-loaded PEG-SS-PCL-SS-PEG micelles exhibited higher therapeutic efficacy than reduction-insensitive PEG-b-PCL micelles in vitro. Thus, end-groups conjugation is a simple and straightforward strategy to introduce intelligent responsiveness in biocompatible block copolymers and improve their therapeutic efficacy.


poly-ε-caprolactone poly(ethylene glycol) block copolymer reductive responsiveness drug release 


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This work was supported by the National Natural Science Foundation of China (Project U1704150) and the Scientific and Technological Projects of Henan Province (182102410017).


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Copyright information

© Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Junbo Li
    • 1
    Email author
  • Junting Jiang
    • 1
  • Biyu Zhou
    • 1
  • Chaohuang Niu
    • 1
  • Wendi Wang
    • 1
  • Wenlan Wu
    • 2
  1. 1.School of Chemical Engineering and PharmaceuticsHenan University of Science and TechnologyLuoyangChina
  2. 2.School of MedicineHenan University of Science and TechnologyLuoyangChina

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