Liver cell culture models are attractive in both tissue engineering and for development of assays for drug toxicology research. To retain liver specific cell functions, the use of adequate cell types and culture conditions, such as a 3D orientation of the cells and a proper supply of nutrients and oxygen, are critical. In this article, we show how extracellular matrix mimetic hydrogels can support hepatocyte viability and functionality in a perfused liver-on-a-chip device. A modular hydrogel system based on hyaluronan and poly(ethylene glycol) (HA-PEG), modified with cyclooctyne moieties for bioorthogonal strain-promoted alkyne-azide 1, 3-dipolar cycloaddition (SPAAC), was developed, characterized, and compared for cell compatibility to hydrogels based on agarose and alginate. Hepatoma cells (HepG2) formed spheroids with viable cells in all hydrogels with the highest expression of albumin and urea in alginate hydrogels. By including an excess of cyclooctyne in the HA backbone, azide-modified cell adhesion motifs (linear and cyclic RGD peptides) could be introduced in order to enhance viability and functionality of human induced pluripotent stem cell derived hepatocytes (hiPS-HEPs). In the HA-PEG hydrogels modified with cyclic RGD peptides hiPS-HEPs migrated and grew in 3D and showed an increased viability and higher albumin production compared to when cultured in the other hydrogels. This flexible SPAAC crosslinked hydrogel system enabled fabrication of perfused 3D cell culture of hiPS-HEPs and is a promising material for further development and optimization of liver-on-a-chip devices.

中文翻译：

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模块化透明质酸-PEG水凝胶的制造，以在灌注的单片肝脏设备中支持肝细胞的3D培养。

肝细胞培养模型在组织工程和药物毒理学研究测定方法的开发中都具有吸引力。为了保留肝脏特有的细胞功能，至关重要的是要使用适当的细胞类型和培养条件，例如细胞的3D方向以及正确供应养分和氧气。在本文中，我们展示了细胞外基质模拟水凝胶如何在灌注的单片肝设备中支持肝细胞的活力和功能。开发，表征并比较了基于透明质酸和聚乙二醇（HA-PEG）的，以环辛炔基部分修饰的，用于生物正交应变促进炔叠氮化物1、3-偶极环加成（SPAAC）的模块化水凝胶系统。与基于琼脂糖和藻酸盐的水凝胶的相容性。肝癌细胞（HepG2）在所有水凝胶中均与活细胞形成球状体，藻酸盐水凝胶中白蛋白和尿素的表达最高。通过在HA主链中包含过量的环辛炔，可以引入叠氮化物修饰的细胞粘附基序（线性和环状RGD肽），以增强人类诱导的多能干细胞衍生肝细胞（hiPS-HEPs）的活力和功能。与在其他水凝胶中培养相比，在用环状RGD肽修饰的HA-PEG水凝胶中，hiPS-HEP在3D中迁移并生长，并显示出更高的生存力和更高的白蛋白产量。这种灵活的SPAAC交联水凝胶系统能够制造hiPS-HEP的灌注3D细胞培养物，并且是用于进一步开发和优化单片肝设备的有前途的材料。