膽管癌病人的膽管腫瘤所引起的嚴重問題之一為膽道阻塞，目前膽道阻塞的主要解決方式為將膽管支架置入人體，而其最主要的後續問題為支架再阻塞的發生，因此需進行二次的內視鏡手術進行治療，但這容易造成病患生命的風險及財務上的負擔，因此本研究將進行自潔多層覆膜的開發，延緩支架再阻塞的情形。
　　本實驗為研究具有自潔功能的覆膜，此覆膜的組成為具有自潔功能的多層可降解薄膜，於其薄膜層中設計其結構的配置，並搭配具有功能性結構的薄膜層，使薄膜在降解時更容易隨結構的崩解而脫落。當覆膜的多層可降解薄膜降解時，附著於覆膜上的髒汙，會隨著PLA (Polylactic Acid)薄膜上圖形的結構崩解成碎片狀而掉落，達到自潔的效果。
　　本實驗設計了不同圖形的邊長尺寸與間距大小，發現奈秒雷射所切割出來可製作覆膜的膠膜，最小結構寬度極限約為0.3 mm；透過降解實驗與交叉比較，由降解的結果推測結構與結構間連接處較少的覆膜，圖形崩解的效果較佳；圖形邊長大小與結構間的間距大小比例大者，結構之間的連接處較易斷裂，有較佳的結構崩解剝離能力；若PLA結構層較薄，降解液體容易滲透至下層PVA(Polyvinyl Alcohol)層，在PVA層快速降解後便可將整層PLA結構層剝除；此實驗亦驗證有結構的覆膜能將附著於其上的髒汙，經由多層膜降解崩離的過程順利全部清除。

Bile duct obstruction is the main problem caused by cholangiocarcinoma. Currently, placing biliary stent in the body is the main solution to biliary occlusion. However, the obstruction could happen again after several months. The secondary endoscopic surgery is a method to solve biliary reocclusion, but it may cause life risk and financial burden. This study is trying to develop a multilayer self-cleaning membrane to postpone stent reocclusion.
This multilayer self-cleaning membrane consists of biodegradable PLA (Polylactic Acid) films and PVA (Polyvinyl Alcohol) films. In order to achieve the functions that the structural membrane can not only degrade into PLA fragments periodically but also clean the attached contaminant away smoothly. The experiments of this study focus on different kinds of designed patterns and intervals.
Based on the limitation of nanosecond laser machine, the minimum interval can be downsized to 0.3 mm. The experimental results show the structural film with narrower intervals between the structures can disintegrate more effectively. Also, the structural film can disintegrate effectively with comparatively large ratio of pattern size and connection interval width. If the PLA structural film is thinner, it would disintegrate rapidly after the solution permeates the film and degrade the under PVA film. In addition, our experiments have proved the structural membrane can clean the attached contaminant during degradation process periodically.

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