Enzymatically degradable temperature-sensitive polypeptide as a new in-situ gelling biomaterial

Yuri Jeong, Min Kyung Joo, Kyung Hyun Bahk, Yun Young Choi, Ho Tae Kim, Won Ki Kim, Hwa Jeong Lee, Youn Soo Sohn, Byeongmoon Jeong

Research output: Contribution to journalArticlepeer-review

129 Scopus citations


We are reporting a poly (ethylene glycol)-block-poly(alanine-co-phenyl alanine) (PEG-PAF) aqueous solution that undergoes sol-to-gel transition as the temperature increases. The sol-to-gel transition was observed at as low a concentration as 3.0-7.0 wt.%. Micellar aggregation accompanying small conformational changes of the peptide from random coils to β-sheets is suggested as the sol-to-gel transition mechanism of the PEG-PAF aqueous solution. The PEG-PAF is stable in phosphate buffered saline, however, it degraded in the subcutaneous layer of rats. In vitro study showed that proteolytic enzymes such as cathepsin B, cathepsin C, and elastase that are present in the subcutaneous layer of the mammalian tissue might be responsible for the degradation of the polymer in rats. As a feasibility study of this material, a single shot of an aqueous insulin formulation (13.8 mg insulin/kg) showed a hypoglycemic effect over 18 days in rats. The current functional polypeptide may be very promising as an in-situ gelling system for tissue engineering, cell/stem cell therapy, and drug delivery.

Original languageEnglish
Pages (from-to)25-30
Number of pages6
JournalJournal of Controlled Release
Issue number1
StatePublished - 1 Jul 2009

Bibliographical note

Funding Information:
This work was supported by the Korea Research Foundation (Grant number KRF-2008-313-C00590), Korea Science and Engineering Foundation grant (KOSEF) funded by the Korea government (MEST) (Grant: R11-2005-008-00000-00 and R01-2007-000-20141-0). YJ and MKJ equally contributed to the paper. MKJ was supported by the Seoul Science Fellowship.


  • Enzymatic degradability
  • Hydrogel
  • Polymer
  • Polypeptide
  • Sol-gel transition


Dive into the research topics of 'Enzymatically degradable temperature-sensitive polypeptide as a new in-situ gelling biomaterial'. Together they form a unique fingerprint.

Cite this