Effect of bioink properties on printability and cell viability for 3D bioplotting of embryonic stem cells
Effect of bioink properties on printability and cell viability for 3D bioplotting of embryonic stem cells
复制标题
生物墨水特性对胚胎干细胞 3D 生物绘图的适印性和细胞活力的影响
DOI：
10.1088/1758-5090/8/3/035020
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发表时间：
2016-09-01
期刊：
影响因子：
9
通讯作者：
Sun, Wei
中科院分区：
文献类型：
--
作者：
Ouyang, Liliang;Yao, Rui;Sun, Wei
3D细胞打印是一项新兴技术，用于制造具有精确和预先设计的几何形状、结构和组成的复杂细胞负载结构，以克服2D细胞培养和传统组织工程支架技术的局限性。这项技术能够对细胞和生物材料进行空间操作，也被称为“生物链接”，因此可以在3D微环境中研究细胞相互作用和/或功能组织和器官的形成。近年来，人们在开发新的生物墨水和应用更多的细胞来源以获得更好的生物相容性和生物功能方面做出了许多努力。然而，在细胞打印过程中，打印参数对3D结构的形状保真度以及细胞活力的影响一直没有得到很好的表征。此外，基于特定细胞类型的参数优化可能不适用于其他类型的细胞，特别是高灵敏度的细胞。在这项研究中，我们系统地研究了挤压细胞打印过程中生物墨水性能和打印参数对生物墨水打印性能和胚胎干细胞（ESC）活力的影响。建立了一种新的方法来确定合适的条件，以实现良好的打印性和高细胞活力。考察了明胶/海藻酸盐生物墨水在不同生物墨水组成、打印温度和保温时间下的凝胶特性。采用新开发的半定量方法对生物油墨的可印刷性进行了表征。结果表明，较长的凝胶时间会导致较差的打印性。活/死实验表明，ESC活力随着打印温度的升高和明胶浓度的降低而增加。此外，ESC活力与诱导剪切应力之间呈指数关系。通过确定合适的印刷适性和可接受的生存能力范围，获得了一个组合参数区域。该研究为3D细胞打印过程的参数优化和微调提供了指导，包括生物标记后的生物墨水可打印性和细胞活力，特别是对于易受损的细胞，如ESCs。
3D cell printing is an emerging technology for fabricating complex cell-laden constructs with precise and pre-designed geometry, structure and composition to overcome the limitations of 2D cell culture and conventional tissue engineering scaffold technology. This technology enables spatial manipulation of cells and biomaterials, also referred to as ‘bioink’, and thus allows study of cellular interactions in a 3D microenvironment and/or in the formation of functional tissues and organs. Recently, many efforts have been made to develop new bioinks and to apply more cell sources for better biocompatibility and biofunctionality. However, the influences of printing parameters on the shape fidelity of 3D constructs as well as on cell viability after the cell printing process have been poorly characterized. Furthermore, parameter optimization based on a specific cell type might not be suitable for other types of cells, especially cells with high sensibility. In this study, we systematically studied the influence of bioink properties and printing parameters on bioink printability and embryonic stem cell (ESC) viability in the process of extrusion-based cell printing, also known as bioplotting. A novel method was established to determine suitable conditions for bioplotting ESCs to achieve both good printability and high cell viability. The rheological properties of gelatin/alginate bioinks were evaluated to determine the gelation properties under different bioink compositions, printing temperatures and holding times. The bioink printability was characterized by a newly developed semi-quantitative method. The results demonstrated that bioinks with longer gelation times would result in poorer printability. The live/dead assay showed that ESC viability increased with higher printing temperatures and lower gelatin concentrations. Furthermore, an exponential relationship was obtained between ESC viability and induced shear stress. By defining the proper printability and acceptable viability ranges, a combined parameters region was obtained. This study provides guidance for parameter optimization and the fine-tuning of 3D cell printing processes regarding both bioink printability and cell viability after bioplotting, especially for easily damaged cells, like ESCs.