Department of Biomedical Engineering, National University of Singapore, 4, Engineering Drive 3, E4-04-10, Singapore 117583, Singapore.
Biofabrication. 2017 Sep 11;9(4):045005. doi: 10.1088/1758-5090/aa8858.
The advent of 3D printing technologies promises to make microfluidic organ-on-chip technologies more accessible for the biological research community. To date, hydrogel-encapsulated cells have been successfully incorporated into 3D printed microfluidic devices. However, there is currently no 3D printed microfluidic device that can support multicellular spheroid culture, which facilitates extensive cell-cell contacts important for recapitulating many multicellular functional biological structures. Here, we report a first instance of fabricating a 3D printed microfluidic cell culture device capable of directly immobilizing and maintaining the viability and functionality of 3D multicellular spheroids. We evaluated the feasibility of two common 3D printing technologies i.e. stereolithography (SLA) and PolyJet printing, and found that SLA could prototype a device comprising of cell immobilizing micro-structures that were housed within a microfluidic network with higher fidelity. We have also implemented a pump-free perfusion system, relying on gravity-driven flow to perform medium perfusion in order to reduce the complexity and footprint of the device setup, thereby improving its adaptability into a standard biological laboratory. Finally, we demonstrated the biological performance of the 3D printed device by performing pump-free perfusion cultures of patient-derived parental and metastatic oral squamous cell carcinoma tumor and liver cell (HepG2) spheroids with good cell viability and functionality. This paper presents a proof-of-concept in simplifying and integrating the prototyping and operation of a microfluidic spheroid culture device, which will facilitate its applications in various drug efficacy, metabolism and toxicity studies.
3D 打印技术的出现有望使微流控器官芯片技术更容易被生物研究界所接受。迄今为止，水凝胶包封的细胞已成功地被整合到 3D 打印的微流控设备中。然而，目前还没有 3D 打印的微流控设备能够支持多细胞球体培养，而多细胞球体培养有利于促进广泛的细胞间接触，对于重现许多多细胞功能生物结构至关重要。在这里，我们报告了首例制造能够直接固定和维持 3D 多细胞球体活力和功能的 3D 打印微流控细胞培养装置。我们评估了两种常见的 3D 打印技术，即立体光固化（SLA）和 PolyJet 打印的可行性，发现 SLA 可以更逼真地原型设计出一种包含细胞固定微结构的设备，这些微结构位于微流控网络中。我们还实现了无泵灌注系统，依靠重力驱动流来进行介质灌注，以减少设备设置的复杂性和占地面积，从而提高其在标准生物实验室中的适应性。最后，我们通过对患者来源的原发性和转移性口腔鳞状细胞癌肿瘤和肝细胞（HepG2）球体进行无泵灌注培养，展示了 3D 打印设备的生物学性能，这些球体具有良好的细胞活力和功能。本文提出了简化和集成微流控球体培养装置的原型制作和操作的概念验证，这将有助于其在各种药物功效、代谢和毒性研究中的应用。
