Cyclic Micropipette Aspiration Reveals Viscoelastic Change of a Gelatin Microgel Prepared Inside a Lipid Droplet
Cyclic Micropipette Aspiration Reveals Viscoelastic Change of a Gelatin Microgel Prepared Inside a Lipid Droplet
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DOI：
10.1021/acs.langmuir.0c00428
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发表时间：
2020-05-19
期刊：
影响因子：
3.9
通讯作者：
Yanagisawa, Miho
中科院分区：
文献类型：
--
作者：
Sakai, Atsushi;Murayama, Yoshihiro;Yanagisawa, Miho
在脂滴内制备的明胶微凝胶由于其纳米结构的差异，具有比体凝胶高得多的弹性。明胶微凝胶的这种纳米结构差异有望为微凝胶提供不同于散装凝胶的独特粘弹性特性。为了澄清这一假设，我们在这里评估了明胶凝胶的频率依赖的粘弹性，通过开发一个循环微移液管抽吸。比较了微凝胶和体凝胶的储存模量E‘（反映弹性）和损失模量E’ '（反映粘度）之间的频率依赖关系。微凝胶的E' ‘/E’比散装凝胶小。由于体胶的E′′/E′之比与浓度无关，因此不同浓度的体胶无法实现微凝胶粘弹性。这些发现意味着在液滴内部制备生物聚合物凝胶有助于通过与液滴界面的相互作用，通过纳米结构转变来改变粘弹性。
Gelatin microgels prepared inside lipid droplets have a much higher elasticity than that of bulk gels because of their differences in nanostructure. This nanostructural difference in gelatin microgels is expected to provide the microgels with unique viscoelastic properties that differ from the bulk gels. To clarify this hypothesis, here we evaluated the frequency-dependent viscoelasticity of gelatin gels by developing a cyclic micropipette aspiration. The frequency-dependent relationship between storage modulus E' (reflecting elasticity) and loss modulus E '' (reflecting viscosity) was compared between the microgels and the bulk gels. The microgels have a smaller E ''/E' than that of the bulk gels. Because the ratio E ''/E' of the bulk gels is constant regardless of the concentration, the microgel viscoelasticity cannot be achieved for the bulk gels with a different concentration. These findings mean that preparing biopolymer gels inside droplets is useful to change the viscoelasticity via nanostructural transition through the interaction with the droplet interface.