Tissue Engineering and Regenerative Medicine

, Volume 15, Issue 4, pp 393–402 | Cite as

Thermoresponsive and Biodegradable Amphiphilic Block Copolymers with Pendant Functional Groups

  • Bo Keun Lee
  • Jung Hyun Noh
  • Ji Hoon Park
  • Seung Hun Park
  • Jae Ho Kim
  • Se Heang Oh
  • Moon Suk KimEmail author
Original Article



To develop the biodegradability and thermoresponsive hydrogel, in this work we designed a pendant-functionalized, thermoresponsive, amphiphilic block copolymer.


Methoxy poly(ethylene glycol) (MPEG)-b-[poly(ε-caprolactone)-ran-poly(ε-caprolactone-3-one)-ran-polylactic acid] (MCL) and (MPEG-b-[PCL-ran-POD-ran-PLA]) [MCL-(CO)] block copolymers were prepared by ring-opening polymerization of ε-caprolactone, OD and lactide monomers. The subsequent derivatization of MCL-(CO) provided MPEG-b-[PCL-ran-poly(ε-caprolactone-3-COOH)-ran-PLA] [MCL-(COOH)] with COOH pendant groups and MPEG-b-[PCL-ran-poly(ε-caprolactone-3-NH2)-ran-PLA] [MCL-(NH2)] with NH2 pendant groups.


The measured segment ratios of MCL-(CO), MCL-(COOH), and MCL-(NH2) agreed well with the target ratios. The abundances of the COOH and NH2 groups in the MCL-(COOH) and MCL-(NH2) copolymers were determined by 1H- and 13C-nuclear magnetic resonance spectroscopy, and agreed well with the target abundances. MCL-(CO), MCL-(COOH), and MCL-(NH2) formed homogeneous, white, opaque emulsions at room temperature. Rheological analysis of the block copolymer suspensions indicated a solution-to-hydrogel phase transition as a function of temperature. The solution-to-hydrogel phase transitions and the biodegradation of MCL-(CO), MCL-(COOH), and MCL-(NH2) were affected by varying the type (ketone, COOH, or NH2) and abundance of the pendant groups.


MCL-(CO), MCL-(COOH), and MCL-(NH2) with ketone, COOH, and NH2 pendant groups showed solution-to-hydrogel phase transitions and biodegradation behaviors that depended on both the type and number of pendant groups.


Thermoresponsive Amphiphilic block copolymers Pendant group Solution-to-hydrogel phase transitions Biodegradation 



This study was supported by a grant from a Basic Science Research Program (2016R1A2B3007448) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education.

Compliance with ethical standards

Conflict of interests

The authors declare no competing financial interests.

Ethical statement

There are no animal experiments carried out for this article.


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Copyright information

© The Korean Tissue Engineering and Regenerative Medicine Society and Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Molecular Science and TechnologyAjou UniversityYeongtong-gu, SuwonRepublic of Korea
  2. 2.Department of Nanobiomedical ScienceDankook UniversityCheonan-siRepublic of Korea

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