Effect of polymer phase transition behavior on temperature-responsive polymer-modified liposomes for siRNA transfection

Kenichi Nagase, Momoko Hasegawa, Eri Ayano, Yoshie Maitani, Hideko Kanazawa

Research output: Contribution to journalArticle

8 Citations (Scopus)


Small interfering RNAs (siRNAs) have been attracting significant attention owing to their gene silencing properties, which can be utilized to treat intractable diseases. In this study, two temperature-responsive liposomal siRNA carriers were prepared by modifying liposomes with different polymers—poly(N-isopropylacrylamide-co-N,N-dimethylaminopropyl acrylamide) (P(NIPAAm-co-DMAPAAm)) and poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) P(NIPAAm-co-DMAAm). The phase transition of P(NIPAAm-co-DMAPAAm) was sharper than that of P(NIPAAm-co-DMAAm), which is attributed to the lower co-monomer content. The temperature dependent fixed aqueous layer thickness (FALT) of the prepared liposomes indicated that modifying liposomes with P(NIPAAm-co-DMAPAAm) led to a significant change in the thickness of the fixed aqueous monolayer between 37C and 42C; while P(NIPAAm-co-DMAAm) modification led to FALT changes over a broader temperature range. The temperature-responsive liposomes exhibited cellular uptake at 42C, but were not taken up by cells at 37C. This is likely because the thermoresponsive hydrophilic/hydrophobic changes at the liposome surface induced temperature-responsive cellular uptake. Additionally, siRNA transfection of cells for the prevention of luciferase and vascular endothelial growth factor (VEGF) expression was modulated by external temperature changes. P(NIPAAm-co-DMAPAAm) modified liposomes in particular exhibited effective siRNA transfection properties with low cytotoxicity compared with P(NIPAAm-co-DMAAm) modified analogues. These results indicated that the prepared temperature-responsive liposomes could be used as effective siRNA carriers whose transfection properties can be modulated by temperature.

Original languageEnglish
Article number430
JournalInternational Journal of Molecular Sciences
Issue number2
Publication statusPublished - 2019 Jan 2


  • Liposome
  • SiRNA delivery
  • Thermoresponsive polymer
  • Transfection

ASJC Scopus subject areas

  • Catalysis
  • Molecular Biology
  • Spectroscopy
  • Computer Science Applications
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

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