在藥物使用的範疇中，如果想要使藥品能夠完全的發揮出療效，藥物的控制與釋放一向是研究的重點；而為了使藥物能達成控制與釋放的目的，藥物載體的利用是不可或缺的一項技術。然而，在各式各樣的藥物載體中，乳化劑型的藥物載體，不論在水溶性或是脂溶性藥物的應用上皆有著極佳的藥物增溶性，是極受重視的一種藥物載體類別。並且在過往的研究文獻中發現，藥物載體的粒徑越為均一，則在應用於藥物的控制與釋放上就越有優勢，但在過去文獻中所提出的製作方式，均無法有效的獲得均一粒徑的載體。

　　由於乳化劑型藥物載體的發展潛力，因此本研究利用鞘流現象設計了一組微流道晶片設備，用於生成均一粒徑乳化球，並且選用常見於藥物載體的褐藻酸鈉材料做為應用。本研究中結合了內部膠化與外部膠化兩種不同生成褐藻酸鈣的機制，希望將此生成均一粒徑乳化球的微流晶片設備，應用於均一粒徑褐藻酸鈣微粒子的製備上。

　　本研究成功的利用所設計的微流道晶片設備，生成均一粒徑乳化球，並且在褐藻膠的應用上，也將此兩種傳統褐藻酸鈣微粒子的生成機制，在個別的實驗設計中實現，並且探討了分離相與連續相流量改變與生成之乳化球大小之關係。由實驗結果中發現，當固定分離相流量時，越大的連續相流量，將得以生成越小的乳化球；相對的，在固定連續相流量的情形下，當分離相的流量越小，所生成的乳化球尺寸也越小。

　　In this paper the manipulation of Ca-alginate microspheres, using a microfluidic chip, for the encapsulation of gold nanoparticles with internal and external gelation methods is presented. Our strategy is based on hydrodynamic-focusing on the forming of a series of self-assembling sphere structures, the so-called water-in-oil (W/O) emulsions, in the cross-junction microchannel.

　　In the internal gelation method, these fine emulsions, consisting of 1.5% w/v Na-alginate and 1.0% w/v calcium carbonate, are then dripped into an oil solution containing 20% v/v glacial acetic acid and 1% v/v Tween 80 to accomplish Ca-alginate microspheres in an efficient manner. The mechanism is that acetic acid reacts with the calcium carbonate to release the calcium ions, and these calcium ions are then crosslinking with the Na-alginate to produce Ca-alginate microspheres.

　　In the external gelation method, these fine emulsions, consisting of aqueous Na-alginates, are then dripped into a solution of 20% calcium salt to accomplish Ca-alginate microspheres in an efficient manner.
We have demonstrated that one can control the size of chitosan microparticles from 100 µm to 1000 µm in diameter (with a variation less than 10%) by altering the relative sheath/sample flow rate ratio The microfluidic chip is capable of generating relatively uniform micro-droplets and has the advantages of active control of droplet diameter, simple and low cost process, and high throughput.

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