肝病在亞洲地區造成極高死亡率，使肝臟移植的需要與日俱增。近二十年間，因肝臟移植手術逐漸普及，其成功率已顯著提升，然而接受移植的病人在術後之主要死因尚有感染及使用免疫抑制劑所造成的副作用。現今對肝病之治療方式以透過移植手術為主，然而手術存在失敗的風險以及供體來源不足等仍是難解問題。以組織工程技術來治療肝臟疾病雖能特別針對受損部位進行修補，但在材料與製程上仍有許多限制，要完成與真實肝組織形態相同之支架仍為極大挑戰。

本研究致力於使用生物可吸收高分子材料，以基層製造技術開發三維結構支架，利用此支架以促使肝組織再生。此新穎技術除了提供傳統微電機製造技術之精確性，更有造價成本低廉與節省時間等優點。此篇研究係利用以甘油為基底之材料製作各種立體多孔支架，用於促使肝細胞再生。肝細胞被預期在廣大範圍之三維幾何設計中增生、延展及移動。此研究中，支架被設計與製造成有一百到九百微米大小之六角形孔洞、以及各種不同機械性質，以利細胞生長。

透過三維列印用於支架製造的高可塑性，此研究的下一步為將肝細胞與血管細胞共同培養，以達成完整的肝臟器官再生。

Liver diseases have been the highest cause of death for many Asian countries, resulting in increasing need for liver transplant. As liver transplantation become more common, the success rate of transplantation surgery had increased dramatically within the past two decades. However, post-surgery infection and side effects from immunosuppressant drugs remain a major cause for post-surgery death in patients. This work focuses on the development of a three-dimensional scaffold via additive manufacturing of biodegradable polymeric material for liver regeneration. The novel technology will provide an alternative toward MEMS-Fab, one technology that is precise, yet extremely expensive and time consuming.

In this work, various 3D porous scaffolds are developed for hepatocyte growth via 3D printing using a novel glycerol-based material. In a wide range of 3D geometric designs, hepatocytes are expected to respond differently through proliferation, elongation, and migration. Here, structures with hexagonal pores are fabricated and seeded with hepatocytes, pore sizes ranging between 100 and 900μm in diameter. Scaffolds of various mechanical properties are also fabricated for optimal cell growth. Utilizing the high flexibility of 3D printing, full liver regeneration with vasculature and hepatocyte co-culture is considered to be the next step of this work.

Abstract 3
List of Figures 7
List of Tables 11
Chaper 1. Introduction 12
1.1 Introduction to Tissue Engineering and Liver Regeneration 12
1.1.1 Liver Tissue Regeneration 15
1.1.2 Overview of Tissue Engineering 16
1.1.3 Scaffolds for Liver Tissue Regeneration 19
1.2 Introduction to Polymer Micro Structure Fabrication 21
1.2.1 Reverse Molding 21
1.2.2 Laser Etching Process 23
1.2.3 Additive Manufacturing 24
1.3 Introduction to Photocrosslinkable and Biodegradable Polymeric Material 26
1.3.1 Poly(Glycerol Sebacate) Acrylate (PGSA) 27
1.3.2 Poly(Ethylene Glycol) Diacrylate (PEGDA) 28
1.3.3 Polycaprolactone Diacrylate (PCLDA) 30
1.4 Evaluation of Liver Regenerating Efficiency 32
1.4.1 Resazurin Reduction Test 32
1.4.2 Albumin ELISA Assay 32
Chaper 2. Experimental Methods and Design 34
2.1 Materials and Equipment 34
2.2 Material Synthesis 36
2.2.1 Synthesis of PGSA 36
2.3 Design and Fabrication of Micro-Patterned Scaffolds 37
2.4 Contact Angle Assay 38
2.5 Cell Culture 38
2.6 Resazurin Reduction Assay 39
2.7 ELISA Albumin Assay 40
Chaper 3. Result and Discussion 41
3.1 Water Contact Angle Assay of Various Biomaterials 41
3.2 Micro-Patterned Scaffolds 43
3.2.1 Single Layer of Hexagonal Wells 45
3.2.2 Scaffolds with Staggered Hexagonal Pattern 46
3.2.3 Sixty Degree Rotated, Six Layer Stacked Hexagonal Scaffold 48
3.3 Cell Proliferation and Attachment Assays 50
3.3.1 Cell Viability with Different Cell Seeding Density 50
3.3.2 Cell Culture on Scaffolds with Different Designs 53
3.3.3 Albumin ELISA Assay 57
3.3.4 Cell Culture on Scaffolds with Different Pore Sizes 59
3.3.5 Cell Culture on Scaffolds with Various Combinations of Materials 61
Chaper 4. Conclusion 66
Chaper 5. Future Work 68
Chaper 6. Reference 69

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