Thermogelable PNIPAM microgel dispersion as 3D cell scaffold: effect of syneresis
Thermogelable PNIPAM microgel dispersion as 3D cell scaffold: effect of syneresis
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作为 3D 细胞支架的热凝胶 PNIPAM 微凝胶分散体：脱水收缩效应
DOI：
10.1039/c0jm00338g
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发表时间：
2010-01-01
影响因子：
--
通讯作者：
Zhang, Yongjun
中科院分区：
文献类型：
--
作者：
Gan, Tiantian;Guan, Ying;Zhang, Yongjun
以聚（N-异丙基丙烯酰胺-co-2-羟乙基甲基丙烯酸酯）（P（NIPAM-HEMA））微凝胶为例，我们提出热凝胶微凝胶分散体可以作为一种新型的可注射细胞支架。然而，这些原位形成的水凝胶随时间收缩，这对于它们用作细胞支架是不期望的。在这项工作中，从聚（N-异丙基丙烯酰胺）（PNIPAM）微凝胶分散体与不同的丙烯酸（AA）含量的水凝胶的脱水收缩进行了测量。这些浓缩的微凝胶分散体都可以在生理pH和离子强度下热胶凝。随着微凝胶中AA含量的增加，分散体的凝胶化温度增加，但所得水凝胶的脱水收缩程度降低。收缩动力学可以很好地描述Tanaka-Fillmore方程，表明水凝胶的去溶胀是由凝胶网络的协同扩散。这些水凝胶呈现出互连的多孔结构，孔径随着脱水收缩程度的增加而减小。将HepG 2细胞接种在这些水凝胶中。当细胞在具有低脱水收缩程度的水凝胶中增殖并形成球状聚集体时，它们的生长在具有高脱水收缩程度的水凝胶中被抑制。这些结果表明水凝胶的脱水收缩对细胞培养具有不利影响。这种影响可以通过调节微凝胶中AA的含量来减轻。然而，如果AA含量太高，导致缺乏细胞-底物相互作用，则细胞也不生长。
Using poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) (P(NIPAM-HEMA)) microgel as an example, we proposed that thermogelable microgel dispersions can be used as a new type of injectable cell scaffolds. However, these in situ formed hydrogels shrink with time, which is undesirable for their use as cell scaffolds. In this work, the syneresis of hydrogels from poly(N-isopropylacrylamide) (PNIPAM) microgel dispersions with various acrylic acid (AA) contents were measured. These concentrated microgel dispersions can all thermally gelate at physiological pH and ionic strength. With increasing AA content in the microgels, the gelation temperature of the dispersion increases, but the degree of syneresis of the resulting hydrogels decreases. The kinetics of shrinkage can be well described by the Tanaka-Fillmore equation, indicating that the deswelling of the hydrogels is governed by the cooperative diffusion of the gel network. These hydrogels present an interconnected porous structure with pore size decreases with an increasing degree of syneresis. HepG2 cells were seeded in these hydrogels. While the cells proliferate and form spheroid-like aggregates in hydrogels with a low degree of syneresis, their growth is inhibited in the one with a high degree of syneresis. These results indicate that the syneresis of the hydrogel has an adverse effect on cell culturing. This effect can be alleviated by adjusting AA content in the microgels. However, cells do not grow either if AA content is too high which results in a lack of cell-substrate interaction.