Miniaturized 3D fibrous scaffold on stereolithography-printed microfluidic perfusion culture

• Main Author: Ng, Feng Lin
• Other Authors: Tan Lay Poh
• Format: Theses and Dissertations
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Materials
• Online Access: https://hdl.handle.net/10356/106569; http://hdl.handle.net/10220/48932
• Institution: Nanyang Technological University

Cells cultured on 2-Dimensional (2D) and 3-Dimensional (3D) substrates generally display significant differences in terms of cell shape, proliferation, morphogenesis and differentiation. While 3D substrates provide better interaction with cell-cell, cell-ECM or cell-soluble factors, tissue construct greater than 200 µm will experience involuntary cell death, e.g. necrosis within the construct. Such an involuntary cell death can be prevented by providing sufficient perfusion through the construct. The objective of this project is to develop a miniaturized 3D micro-perfused system where cells are provided with a highly relevant micro-environment by adopting the use of 3D scaffold and local perfusion. The 3D fibrous scaffold used in this study was to recapitulate the fibrillary and porous nature of the extracellular matrix of a native tissue. At the same time, local perfusion was provided to ensure sufficient exchange of nutrients and metabolites. The proposed setup is much preferred over the conventional 2D static culture since it better mimics the in vivo micro-environment, especially for highly perfused organ such as liver. To realize the idea and design of the micro-perfused platform, an Electrospinning auxiliary jig has been designed for the collection of 3D aligned or random scaffold. For a demonstration, 3D random scaffold has been embedded on a Stereolithography-printed perfused platform. A one-step Stereolithography process has been developed where the 3D fibrous scaffold was embedded without any tedious secondary assembly processes. This is the first instance where a miniaturized 3D fibrous scaffold has been embedded on a Stereolithography-printed perfused microfluidic platform. Huh7.5 hepatocellular carcinoma cells were used as model cells for this platform since liver hepatocytes experienced similar perfused micro-environment. Preliminary cell studies revealed that Huh7.5 presents sufficient cells viability and proliferation on the micro-perfused system. Cells infiltration were found to be better than a static culture due to the presence of fresh medium and the gene expression of Albumin and CYP3A cytochrome was found to be much upregulated as compared to its static counterpart. Taken together, the newly developed device has proven to be a physiologically-relevant platform for the maintenance of liver hepatocytes. While the embedded scaffold for this instance was of random nature since the extracellular matrix (ECM) of liver do not exhibit any preferential alignment; the use of 3D aligned fibrous scaffold on the platform is possible. The device developed in this study has proved to be highly versatile and tailorable that suits the local in vivo micro-environment of various organs and tissues to be studied in future.