Increasing Elasticity through Changes in the Secondary Structure of Gelatin by Gelation in a Microsized Lipid Space

Atsushi Sakai, Yoshihiro Murayama, Kei Fujiwara, Takahiro Fujisawa, Saori Sasaki, Satoru Kidoaki, Miho Yanagisawa

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Even though microgels are used in a wide variety of applications, determining their mechanical properties has been elusive because of the difficulties in analysis. In this study, we investigated the surface elasticity of a spherical microgel of gelatin prepared inside a lipid droplet by using micropipet aspiration. We found that gelation inside a microdroplet covered with lipid membranes increased Young's modulus E toward a plateau value E∗ along with a decrease in gel size. In the case of 5.0 wt % gelatin gelled inside a microsized lipid space, the E∗ for small microgels with R ≤ 50 μm was 10-fold higher (35-39 kPa) than that for the bulk gel (∼3 kPa). Structural analysis using circular dichroism spectroscopy and a fluorescence indicator for ordered beta sheets demonstrated that the smaller microgels contained more beta sheets in the structure than the bulk gel. Our finding indicates that the confinement size of gelling polymers becomes a factor in the variation of elasticity of protein-based microgels via secondary structure changes.

Original languageEnglish
Pages (from-to)477-483
Number of pages7
JournalACS Central Science
Volume4
Issue number4
DOIs
Publication statusPublished - 2018 Apr 25

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)

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