| 摘要: | 摘要 就我們所知，人體內的細胞本生長在由細胞外間質構築而成的三維空間裡，而那些人工製造的三維細胞培養支架，即稱之為「鷹架」。在我們實驗室利用微流體通道製造出大小均一的組織應架，利用組織鷹架來培養細胞，並研究鷹架孔洞的大小與硬度對於細胞在三維空間生長的現象來進行分析。然而，我們希望將鷹架孔洞的大小，推進到更小的尺度(<50μm)，進行小尺度孔洞鷹架實驗。但在利用泡泡製作鷹架的系統中，產生泡泡的尺度越小，「粗化」的現象就越嚴重[註一]。因此，我們嘗試使用乳化液系統(水包油)，將大大降低粗化的現象。不過，在微流體通道的系統中，我們所使用的PDMS微流道晶片，通道表面是疏水性的，所以無法穩定的製造乳化液。我們必須先對它做表面的親水性改質，讓微流道能夠穩定，且長時間的製造乳化液。另外，在高產率的條件下製造乳化液，製造的狀態是噴射態，所以收集乳化液的油分率很低，但這不是我們想要的(在培養細胞所需鷹架的條件，最好要超過64%。)。為了提高油分率，我們成功的製造像「梳子」形狀的微流體通道，將低油分率的乳化液(~20%)，有效的提高至超過~64%的油分率。在這實驗的過程中，也有一些新的發現，例如:1.乳化液分流的速度門檻比率為Vcomb/Vmain=0.58。2.利用電路圖模擬微流體通道的應用，可快速粗略得到模擬結果，並幫助設計微流道減少過多的測試。 註一:泡沫是很不穩定的系統，在氣泡裡的氣體分子會擴散到液體中，造成壓力變化。當氣泡縮小時，來自表面張力的拉普拉斯壓力會增加，加速了氣體分子擴散出去的速度，這個過程叫「粗化」。Abstract To our knowledge, Cells in our bodies are surrounded by 3D environment which is mainly composed of extracellular matrix (ECM). An artificial 3D cell culture support in 3D is often called a scaffold. In our lab, we used microfluidic channel to make a uniform tissue scaffold, and use this scaffold to cell culture. Then, we studied and analyzed the phenomenon of cell culture in 3D space of different pore size and hardness. However, we hope to get smaller pore size scaffold (<50μm). But, in the bubble system, to make smaller bubbles, the coarsening problem will get serious [1]. Therefor, we tried to use the emulsion system (oil in water) to solve coarsening phenomenon. However, in the microfluidic channel system, we used PDMS microfluidic chip channel surface is hydrophobic, which couldn’t create a stable emulsion. We must modify surface with hydrophilic property, let microfluidic channel could stable and long-term manufacturing emulsion. In addition, the state is jetting mode when make emulsion in high generate frequency. So the collected oil fraction is very low, but we don’t want the low oil fraction emulsion (in cultured cells, the conditions required for scaffold is best to more than 64%). In order to improve the oil fraction, we successfully made a "comb" shape microfluidic channel and effectively increased the oil fraction from 20% to more than 64%. In the course of the experiment, there are some new findings, such as: 1. The critical boundary condition of emulsion separation flow rate is Vcomb / Vmain = 0.58. 2. The application of circuit simulation in microfluidic channels, we may fast and roughly to get simulation results, and help the design of microfluidic channel to reduce excessive experiment test. |
