心血管疾病與糖尿病一直名列於國人十大死因前三名，而目前以人工血管修復或替代因動脈病變而損壞的血管組織、以及進行洗腎動靜脈之廔管，就長期而言其再阻塞造成血栓的可能性以及非自體排斥，一直是需要克服的問題。利用胚胎幹細胞研究血管的再生技術，或許可以細胞治療的方法誘導血管修復、或是提供患者另一種移植血管的來源，免受自體或人工血管移植之苦。然而，若要將幹細胞應用於醫學，必須對其未分化/分化機制、分化路徑等作完整的了解。由於其於生物體中所處的複雜微環境包括化學、物理、機械等變因，一般的體外培養無法模仿其生理環境。而本論文即欲開發一微流體晶片來應用於幹細胞研究上，以快速檢視小鼠胚胎幹細胞於體外分化為血管細胞的最佳生長因子濃度組合。
本研究旨在製作一微流體晶片，可以同時產生兩種生長因子VEGF及bFGF之多種濃度組合，並使小鼠胚胎幹細胞培養於內並進行長期分化，以快速找到最佳分化環境。為了達到此研究目的，針對生長因子此種大分子量之藥品進行濃度梯度產生器的設計。此外，考慮細胞的生長環境與生長因子的有效時限，本論文亦包括氧氣通透度、細胞培養於微流到元件之參數及溫度控制等參數之計算及測試。最後，本論文對元件設計中的濃度梯度產生器與微混合器進行功能性測試，驗證其功能；另外，亦針對小鼠胚胎幹細胞之分化結果，進行免疫螢光染色與微型生物分析儀兩種量測與分析，並針對分析方法進行比較。

Stem cells differentiation relies on microenvironment control for inductive signaling and initiation. In finding the optimum growth factor (GF) combinations for mouse embryonic stem cells (mESCs) differentiation into endothelial cells (ECs) and smooth muscle cells (SMCs), which are important cells for building blood vessels, we developed a continuous-flow cell culture plate with integrated microfluidic mixers. The continuous feeding of medium allows us to conduct long-term differentiation process of the ECs without moving the plate conventionally needed for changing the medium and further reduces the autocrine and paracrine signaling. The need to continuously supply medium in a few 10’s L/hr to the cells etc. determines the flow velocity and the needed mixer channel length. Since the molecular weight of these GFs are typically a few 10’s~100’s kDa in sizes, a conventional serpentine mixer with diffusion-limited laminar flow mixing will not mix the molecules adequately within a millimeter-size microfluidics channel. Therefore, the cell culture plate consists of a 7-stage staggered-herringbone-ridge serpentine mixers that enable GFs to mix completely within a few millimeters, and an array of cell culture wells.

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