Biaxial stretching of polytetrafluoroethylene in industrial scale to fabricate medical ePTFE membrane with node-fibril microstructure  

作　　者：Gang Wang Yusheng Feng Caiyun Gao Xu Zhang Qunsong Wang Jie Zhang Hongjie Zhang YongqiangWu Xin Li Lin Wang Ye Fu Xiaoye Yu Deyuan Zhang Jianxiong Liu Jiandong Ding 

机构地区：[1]State Key Laboratory of Molecular Engineering of Polymers,Department of Macromolecular Science,Fudan University,Shanghai 200438,China [2]R&D Center,Lifetech Scientific(Shenzhen)Co.,Ltd.,Shenzhen 518057,China [3]R&D Center,Lifevalve Medical Scientific Co.,Ltd.,Shenzhen 518057,China

出　　处：《Regenerative Biomaterials》2023年第1期1161-1177,共17页再生生物材料（英文版）

基　　金：supports from National Natural Science Foundation of China(grant no.52130302);National Key R&D Program of China(grant no.2016YFC1100300)。

摘　　要：Expanded polytetrafluoroethylene(ePTFE)is promising in biomedical fields such as covered stents and plastic surgery owing to its excellent biocompatibility and mechanical properties.However,ePTFE material prepared by the traditional biaxial stretching process is with thicker middle and thinner sides due to the bowing effect,which poses a major problem in industrial-scale fabrication.To solve this problem,we design an olive-shaped winding roller to provide the middle part of the ePTFE tape with a greater longitudinal stretching amplitude than the two sides,so as to make up for the excessive longitudinal retraction tendency of the middle part when it is transversely stretched.The as-fabricated ePTFE membrane has,as designed,uniform thickness and node-fibril microstructure.In addition,we examine the effects of mass ratio of lubricant to PTFE powder,biaxial stretching ratio and sintering temperature on the performance of the resultant ePTFE membranes.Particularly,the relation between the internal microstructure of the ePTFE membrane and its mechanical properties is revealed.Besides stable mechanical properties,the sintered ePTFE membrane exhibits satisfactory biological properties.We make a series of biological assessments including in vitro hemolysis,coagulation,bacterial reverse mutation and in vivo thrombosis,intracutaneous reactivity test,pyrogen test and subchronic systemic toxicity test;all of the results meet the relevant international standards.The muscle implantation of the sintered ePTFE membrane into rabbits indicates acceptable inflammatory reactions of our sintered ePTFE membrane fabricated on industrial scale.Such a medical-grade raw material with the unique physical form and condensed-state microstructure is expected to afford an inert biomaterial potentially for stent-graft membrane.

关 键 词：biomedical polymer medical-grade raw material expanded polytetrafluoroethylene olive roller polymer processing biaxial stretching 

分 类 号：R318[医药卫生—生物医学工程]