支架之結構，生物相容性與生物降解性等特性在細胞成長過程中扮演非常重要角色。因此，本研究透過新穎靜電紡絲技術製備相似天然細胞外基質 (extracellular matrix，ECM) 之結構與高空孔性，大比表面積等特點之生物可降解性聚乳酸高分子 (poly(L-lactide)，PLLA) 和不同配比之聚乳酸/聚甘醇酸共聚物 (poly(lactide-co-glycolide)，PLGA)纖維支架。
　　所製備之支架材料經掃描式電子顯微鏡 (Scanning electronic microscopy，SEM) 觀察其微觀結構，結果顯示以靜電紡絲法已成功地製備出纖維直徑分佈於1200 nm至1500 nm間之高空孔性PLLA與不同配比之PLGA纖維支架。同時以X光繞射儀 (X-ray diffraction，XRD) 與示差掃描式熱分析儀 (Different scanning calorimeter，DSC) 分析PLLA及85/15與75/25 PLGA結構性質，結果顯示靜電紡絲快速抽絲特點皆易致使PLLA與不同配比PLGA呈現低結晶性與冷結晶峰產生。此外，利用XRD 1維和2維分析經熱處理過後之纖維支架，結果顯示聚甘醇酸 (polyglycolide，PGA) 添加量愈多雖然易致使結晶度的下降，然而卻有利於順向性之提升；於DSC結果中也可觀察到PGA含量愈多，其吸熱熔融峰往低溫位移與焓值之降低。
纖維支架體外降解測試經SEM觀察顯示，纖維降解的發生隨著降解天數增加，纖維支架開始產生斷裂。比較不同PGA含量纖維支架的降解速率，結果顯示PGA添加量愈多，降解速度愈慢。體外生物相容性測試結果說明PLLA與85/15與75/25 PLGA纖維支架不會對細胞生長造成毒害，且有利於細胞在支架上進行增生。

It is well known that the structure, biocompatibility and biodegradation of characteristic scaffold plays an important role to control the cell growth behavior. Therefore, in this study, the high porosity and surface area with interconnected pore network of biodegradable poly(L-lactide) (PLLA) and poly(lactide-co-glycolide) (PLGA) fiber scaffold were fabricated using electrospun technology. The structure of prepared PLLA and PLGA is similar to the dimension of extracellular matrix (ECM) scaffold.
The micrographs of scanning electronic microscopy (SEM) illustrate that the fiber diameter was distributed between 1200 nm and 1500 nm for PLLA, 85/15 PLGA and 75/25 PLGA fiber scaffold. The structure and property of PLLA, 85/15 PLGA and 75/25 PLGA fiber scaffold were investigated by X-ray diffraction (XRD) and different scanning calorimeter (DSC). The XRD and DSC results indicated that the crystallinity of prepared fiber scaffold with a clear cold crystallization peak was relatively low. In addition, the fiber scaffold was annealed at 120 ℃ for 6 hr and then was measured by one-dimensional and two-dimensional XRD. Experimental result showed the crystallinities decreased by increasing content of PGA. At the same time, the orientation of polymer chain became apparent by adding the PGA. Thermal treatment of PLLA, 85/15 PLGA and 75/25 PLGA fiber scaffold revealed that the melting endotherm became weaker, broader and slightly shifted to low temperatures as content of PGA increased.
The degradation of fiber scaffold was observed by SEM. Experimental result showed that the structural changes of PLLA fiber scaffold during the in vitro degradation, which the fiber scaffold started to break down. Compared to the date of different content of PGA fiber scaffold, the SEM micrographs illustrate that the degradation rate was decreased by increasing content of PGA.
In vitro biocompatibility measurement of PLLA, 85/15 PLGA and 75/25 PLGA fiber scaffold was investigated by optical microscopy. Experimental result indicated that PLLA, 85/15 PLGA and 75/25 PLGA didn’t have toxic effect on MDCK cells, which can be used as the scaffold materials for MDCK cell growth.

摘要………………………………………………………………………I
Abstract…………………………………………………………………II
總目次…………………………………………………………………III
圖目次……………………………………………………………………V
表目次…………………………………………………………………VIII
第一章 緒論…………………………………………………………1
1-1 研究背景……………………………………………………1
1-2 研究動機……………………………………………………3
1-3 研究方向……………………………………………………3
第二章 文獻回顧……………………………………………………4
2-1 生物可分解材料……………………………………………4
2-1-1 聚乳酸 (polylactide)……………………………………4
2-1-2 聚甘醇酸 (polyglycolide)………………………………6
2-1-3 聚乳酸/聚甘醇酸 (poly(lactide-co-glycolide) ……6
2-1-4 降解機制與影響因素………………………………………9
2-2 靜電紡絲 (electrospinning) 製程……………………12
2-2-1 靜電紡絲簡介………………………………………………12
2-2-2 影響纖維形態之參數………………………………………13
2-2-3 系統穩定性之設計…………………………………………22
2-3 靜電紡絲製程對材料結構與性質影響……………………23
2-4 靜電紡絲纖維應用於組織工程……………………………26
第三章 實驗方法與步驟……………………………………………31
3-1 實驗材料……………………………………………………31
3-2 實驗儀器……………………………………………………33
3-3 實驗流程……………………………………………………34
3-4 實驗步驟……………………………………………………35
3-4-1 聚乳酸及其共聚物溶液製備………………………………35
3-4-2 靜電紡絲製程………………………………………………35
3-4-3 生物降解性測試……………………………………………36
3-4-4 生物相容性測試……………………………………………37
3-4-5 纖維支架之退火處理………………………………………37
3-4-6 纖維支架之淬火處理………………………………………37
3-5 實驗儀器分析………………………………………………38
第四章 結果與討論…………………………………………………40
4-1 高分子溶液性質與製程參數對靜電紡絲纖維形態影響…40
4-1-1 高分子溶液濃度對靜電紡絲纖維形態影響………………40
4-1-2 電場強度對靜電紡絲纖維形態影響………………………42
4-1-3 推料速度對靜電紡絲纖維形態影響………………………44
4-1-4 氮氣流率對靜電紡絲纖維形態影響………………………46
4-2 聚乳酸及其共聚物靜電紡絲纖維支架……………………48
4-2-1 PLLA與PLGA纖維支架形態分析……………………………48
4-2-2 PLLA與PLGA纖維支架接觸角分析…………………………48
4-2-3 PLLA與PLGA纖維支架結構分析……………………………53
4-2-4 PLLA與PLGA纖維支架熱性質分析…………………………59
4-3 聚乳酸及其共聚物靜電紡絲纖維支架之體外試驗分析…65
4-3-1 生物降解性測試……………………………………………65
4-3-1-1 微結構觀察…………………………………………………65
4-3-2 生物相容性測試……………………………………………70
第五章 結論…………………………………………………………74
參考文獻…………………………………………………………………75

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