本研究利用微機電系統製程技術開發微流體乳化晶片，並成功地將其應用於基因轉殖技術上。此乳化晶片的優點是製作出比傳統方法更具高均一性的乳化液滴顆粒以增加DNA轉殖的效率，此外，此系統可取代傳統大型儀器的繁複操作過程。此論文包含兩種微流體系統晶片設計:一種為傳統式T行交叉式(T-junction)系統晶片，另一種則為可調式氣閥晶片(Active tunable moving wall)。有別於傳統式T行交叉式晶片，新型晶片主要是在T行交叉式晶片微流體管道上加了一組氣閥，此氣閥可以藉由氣壓大小來調控流體管道的寬度，進而控制乳化液滴的尺寸。
此微流體晶片製程是以SU-8光阻製程先建構出各層平台之母模結構，再以聚二甲基矽氧烷（Polydimethylsiloxane: PDMS）材料翻模，及後續的晶片組裝而成。此外，本研究比較利用鯊烯及大豆油當做油相，並利用上述兩種微流體晶片設計置備高均一性的乳化液滴，並測試其用於基因轉殖之效果。
在現有的條件之下所得的實驗結果可得知，鯊烯本質接近生物體，轉殖效果比大豆油的來得好。此外，本研究中，兩種微流體晶片在產生乳化液滴之評估上，T型交叉式晶片系統中，流速比越大，乳化液滴尺寸越小，轉殖效率越高。另外，在可調式氣閥晶片中，氣閥壓力越大，產生的液滴尺寸也越小，在此系統中，因只需改變氣閥壓力，便可控制顆粒的大小，如此提供良好的操控性。相對於傳統型T型交叉式晶片，新型晶片不僅可以產生大小均一的基因轉殖載體(乳化液滴)，並可減少連續相的浪費而減少操作成本。本研究希望能藉由此系統的發展，應用在更多的生醫技術上。

This study reports a new microfluidic system to generate micro-scale droplets for high efficient gene delivery. Compared with the conventional way for micro-droplet formation, the proposed system not only can uniformly create micro-droplets and hence enhancing the efficiency of the subsequent gene delivery but also can largely minimize the lengthy processes operated in the traditional devices of similar function. In this study, two types of microfluidic systems were designed including traditional design of microchannel with T-junction layout and a new design with a membrane-based pneumatic microvalve integrated in the tradition one. In this improved design, the size of the micro-droplets can be fine-tuned by the width of the microchannel, controlled by the applied air pressure to the incorporated microvalve. In this work, the fabrication of the microfluidic systems is based on SU-8 lithography and PDMS (poly-dimethylsiloxane) replication processes.
In this study, two kinds of oil phase (squalene and soybean oil) were used to generate micro-droplets and were tested in terms of the efficiency of the subsequent gene delivery. Also, the two types of microfluidic systems proposed were evaluated experimentally with respect to their performance on micro-droplet formation. Experimental data showed that the oil-in-water droplets were better than water-in-oil droplets on in vitro gene delivery. In addition, compared with the soybean oil counterpart, squalene-based micro-droplets have higher efficiency on gene delivery. Regarding to the size of micro-droplets, in the traditional design of microchannel with T-junction layout, it was observed that the higher the flow rate the smaller the droplet size is, which contributes to higher efficiency of gene delivery. Very similarly, in the new design with a membrane-based pneumatic microvalve integrated, it was found that the higher the applied air pressure in the pneumatic microvalve, the smaller the droplet size is. In contrast to the traditional T-junction design, the proposed new design not only offers a new way to control the size of the generated micro-droplets, reduces the waste of the continuous phase but more importantly, generates micro-droplets with higher size uniformity. This is found particularly useful for a high efficient gene delivery.

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