A Study of Biodegradable Multilayer Thin Film for Biomedical Stent

• Main Authors: Wei-Hao Geng, 耿緯皓
• Other Authors: Fuh-Yu Chang
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/40910845318094225134

碩士 === 國立臺灣科技大學 === 機械工程系 === 104 === Currently in the study of bile duct carcinoma, biliary stenosis is the biggest problem by tumor in the bile duct, and biliary stent as one way of treatment, then it may happen restenosis phenomenon when you place the biliary stent. In this view point, we present the study to explore using multi-layered biodegradable film to improve this problem. In this research, in order to improve when placing biliary stent may occur restenosis phenomenon, we explore the self-cleaning properties of multilayer film and the method of fabricating the multilayer film. Therefore, this study divided into two parts to research this purpose. The first part is using a shuttle dipping method to fabricate each layer of polymer film, and this process is good for film thickness and uniformity control, and then using different characteristics in degradation rate of each layer, so that bottom film rapidly degraded, resulting a slow degradation of the upper layer loss the support then peel off to achieve the purpose of self-cleaning film. Among the part of multilayer film degradation experiment, we dip the PLGA on the hydrocolloids to verity the self-cleaning by multilayer in the short time. The second part is to explore the microstructure fabrication by circular imprint methods. First, we use silicon linear microstructure master and electroforming method to fabricate flexible molds, then use a nitinol spring to carry on a circular thermal imprint. It successfully makes circular structures on a 30um thickness PLGA film, and the experimental results indicate the special circular imprint process with duration 20 minutes, temperature 85C and pressure 0.04Mpa can achieve the transfer rate by 90.01%. The second is to explore the feasibility of using PDMS soft mold of endless transfer by hydrocolloids. The results confirmed that the circular PDMS structure can be transferred to circular hydrocolloids structure, even the rate reach 97.7%. This part achieves the fabrication of degradable circular structure. The two methods could be applied to fabricate microstructure circular membranes for biomedical stents in the future.