本研究探討以液態動力流體聚焦技術，利用同軸式噴嘴，產出單分散生物聚合物微球之機制。生物聚合物微球於醫療上目前有蛋白質組織學、軟組織填充劑、經導管肝動脈栓塞術等不同應用。流體聚焦技術的優點在於其可以穩定地將液束拉伸至毫米，乃至奈米級，且容易產生大量單分散性之生物微球，且此技術未來可發展成生產微膠囊、微膠體等多種包覆微粒。本實驗研究目標為產生10μm -500 μm 之可調控單粒徑生物聚合物微球，以因應醫療上之應用。

流體聚焦實驗採用雙管注射幫浦，以連續相流體聚焦分散相流體，並在噴嘴流道中央裝設一支150μm 孔徑的微型噴嘴，以加強聚焦現象。本研究所使用的工作流體為PVA/D.I. water、PLGA/DCM、PCL/DCM 等材料。微球生產控制參數為流體流量、流體流量比、速度、雷諾數、分散相流體黏度等。研究結果顯示，當連續相流體流量上升或分散相流體流量下降，微球粒徑皆有變小的趨勢，而當流體流量比上升時，也會使得微球粒子有下降的趨勢。速度和雷諾數為影響流場主因，當兩者上升時，粒子也會有變小的趨勢。而雷諾數超過1100 時，微球粒徑會漸漸趨向一個定值。當分散相流體黏度從3cp 上升到13cp 時，在聚焦後可以產生較大的微球粒徑和粒徑比(DV84/DV50)的值，顯示在較低黏度時，微球較為均勻。以高速攝影機照相觀察，發現最小微球粒徑約在30-50μm 之間。將產出的微球泡水乾燥一周後，觀察兩種材料的收縮率，發現當PLGA/DCM=1/9 時，收縮率介在0.45-0.55 之間，當PCL/DCM=1/4 時，收縮率介在0.6-0.75 之間。以此收縮比率，本實驗可產出約10μm 之均勻且單一分佈性微球，顯示本研究所發展的液態動力流體聚焦噴嘴可以產生大量均勻的微米級之生物微球，適合做為醫療上之應用。

This research investigates the production of monodispersed bio-polymer microspheres produced by hydrodynamic flow focusing nozzle. The medical materials used in biological applications include proteomics, soft tissue fillers, transcatheter hepatic arterial embolization and many others. The advantages of the flow focusing technique result from its capability to stretch the jet diameter from a millimeter to nanometer levels.After rupturing, it’s prone to break uniformly with a large amounts of single biological monodispersed microspheres. This technique can be made with
producing microcapsules, microgels , and coated particles. This research aims at the production of particles ranging from 10μm -500 μm of adjustable single-sized biopolymer microspheres,for medical applications. Microspheres are produced by using two syringe pumps, one is used to pump the
continuous phase and the other is used to pump the coaxial dispersed phase . A nozzle with a 150μm orifice in the channel center is installed for the injection of the dispersed phase flow.
The working fluids used in this study were PVA / D.I. water, PLGA / DCM, PCL / DCM. Controlling parameters of the microspheres production are the fluid flow rates, flow ratios, flow velocity, Reynolds number, and the viscosity of the dispersed phase fluid. Results showed that when the continuous phase flow rate increased or dispersed phase fluid flow rate decreased, microspheres became smaller. When the fluid flow is ratio increased , the diameters of microsphere particles would be deceased. The velocity and Reynolds number are the main parameters of the flow field.When both of them were increased, microspheres became smaller. While Reynolds number was over 1100, the microsphere size will gradually tend to a constant value. Finally, when the viscosity of the dispersed phase rose from 3cp to 13cp, the size and DV84/DV50 of microspheres become larger. This indicates that microspheres produced under lower viscosity will more uniform. After soaking the microspheres in water for a week,the microspheres were dried to observe the shrinkage of the particles.It is found that the shrinkage was 0.6-0.75 as PLGA / DCM = 1/4 and 0.45-0.55 as PCL / DCM = 1/9 respectively. Based on the shrink ratio, the flow focusing nozzle can produce monodispersed microspheres with size about 10μm.This shows that the development of hydrodynamic flow focusing nozzle can produce large amounts of bio-microspheres with uniform micron level
which is suitable for medical applications.

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