隨著生物可降解高分子的應用在組織工程中越來越普遍，在過去的二十年中，可生物降解高分子的應用越加廣泛。由於大多數傳統的可生物降解聚合物是熱塑性聚合物材料，所以可生物降解的支架和裝置，其製造部分僅限於熱固化型。同時，許多現有的生物可降解高分子受限於植入時的快速降解，極高的機械性質和有限的官能基，造成生物可降解高分子的應用備受限制。由於機械強度高，大多數常見的可生物降解高分子用於骨組織工程。然而，整體僵硬的機械性能導致缺乏軟組織工程材料的選擇。在本計畫中，三種可生物可降解和生物可相容之高分子因為它們的光固化特性而被選擇：Poly(caprolactone) diacrylate (PCLDA), Poly(ethylene glycol) diacrylate (PEGDA) and Poly(glycerol sebacate) acrylate (PGSA)。透過調整高分子的各種組合，共聚物展現出楊氏模量在0.5-10MPa之間，正好在一般的軟組織機械性能周圍。再者，通過3D打印製造的共聚物展現出比通過UV光製造的高分子更高的機械強度。通過拉力分析，極限拉伸強度，斷裂伸長率和降解性質，幾種組合被鑑定為用於軟組織（例如心臟，肺，肝，腎和脈管系統再生）的有用材料。此外，具有光固化能力，使得共聚物展現出很好的裝置和支架形成能力。

As the applications of biodegradable polymers become more common in tissue engineering, a wide range of biodegradable polymers became available over the last two decades. As most traditional biodegradable polymers were thermoplastic polymeric materials, the fabrication of biodegradable scaffolds and devices were limited to thermal molding. Meanwhile, many of the existing biodegradable polymers suffer from a short half-life due to rapid degradation upon implantation, exceedingly high stiffness, and limited ability to functionalize the surface with chemical moieties. With the high mechanical strength, most common biodegradable polymers became useful in bone tissue engineering. However, the overall stiff mechanical properties lead to the lack of choice of material for soft tissue engineering. In this work, the combination between three biodegradable and biocompatible polymers is explored through photocuring: Poly(caprolactone) diacrylate (PCLDA), Poly(ethylene glycol) diacrylate (PEGDA) and Poly(glycerol sebacate) acrylate (PGSA). The various combinations of copolymer composition led to products with Young’s modulus ranging between 0.5-10 MPa, right around the general soft tissue mechanical properties. In addition, copolymers fabricated by 3D-print fabrication show higher mechanical strength than those fabricated via direct UV exposure. Through the analysis of substrate stiffness, ultimate tensile strength, elongation at break and the degradation properties, several combinations are identified as useful materials for soft tissues, such as heart, lung, liver, kidney, and vasculature regeneration. With the photocuring capabilities, the copolymers exhibit great devices and scaffold formation capabilities.

Table of Content
摘要 2
Abstract 3
1 Research Background 9
1.1 Introduction to Tissue Engineering 9
1.1.1 Mechanical Properties of Soft Tissues 12
1.2 Introduction to Common Biodegradable Polymer 12
1.2.1 Poly(Glycerol Sebacate) Acrylate 14
1.2.2 Polycaprolactone Diacrylate 15
1.2.3 Poly(Ethylene Glycol) Diacrylate 17
1.2.4 Introduction to Mechanism of Biodegradation 18
1.3 Scaffold Fabrications for Tissue Engineering 20
1.3.1 Common Scaffold Fabrication Methods 20
1.3.2 Digital Light Processing Additive Manufacturing 21
1.4 Motivation and Purpose 22
2 Experimental Method 24
2.1 Material and Equipment Selection 24
2.2 Preparation of Materials 24
2.2.1 Synthesis of PGS 24
2.2.2 Synthesis of PGSA 25
2.2.3 Synthesis of PCLDA 25
2.2.4 Preparation of PEGDA 26
2.3 Polymer Mixture 26
2.4 Fabrication of Polymer Samples 26
2.4.1 Direct UV Exposure 27
2.4.2 Digital Light Processing Additive Manufacturing 27
2.5 Measurement of Mechanical Properties 28
2.6 In Vitro Degradation 28
2.6.1 Degradation of Copolymer Fabricated via direct UV exposure 29
2.6.2 Degradation of Copolymer Fabricated via Digital Light Processing 30
2.6.3 Measurement of Swelling Ratio 32
2.7 Liver Tissue Regeneration Scaffolds 32
2.7.1 Design of Liver Tissue Regeneration Scaffolds 32
2.7.2 DLP-AM Fabrication of Liver Tissue Regeneration Scaffolds 33
3 Result and Discussion 34
3.1 Mechanical Properties of Copolymers 34
3.1.1 Mechanical Properties of Pure Materials 34
3.1.2 Properties of PGSA-co-PEGDA 36
3.1.3 Properties of PGSA-co-PCLDA 38
3.1.4 Properties of PCLDA-co-PEGDA 40
3.2 Degradation Results of Copolymer 41
3.2.1 The Degradation of Copolymer PGSA-co-PEGDA 42
3.2.2 The Degradation of Copolymer PGSA-co-PCLDA 45
3.2.3 The Degradation of Copolymer PCLDA-co-PEGDA 48
3.3 Application in Tissue Engineering 51
3.4 Scaffold Formation 53
4 Conclusion 56
5 Future Work 58
6 Reference 63
7 Appendix 68

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