Zou Ting, Wang Lu, Li Wenchao, Wang Wenzu, Chen Fang, King Martin W
Key Laboratory of Textile Science and Technology of Ministry of Education and College of Textiles, Donghua University, China.
Key Laboratory of Textile Science and Technology of Ministry of Education and College of Textiles, Donghua University, China.
J Mech Behav Biomed Mater. 2014 Oct;38:17-25. doi: 10.1016/j.jmbbm.2014.06.004. Epub 2014 Jun 16.
Bioresorbable ureteral stents have the advantage of eliminating the need for a second removal surgery and hence avoiding certain complications. However the inadequate mechanical performance and lack of control over the rate of resorption limit the use of current prototype designs. This paper focuses on a series of resorbable millimeter-sized stents which were fabricated by a unique combination of braiding and thermal treatment processes. Their mechanical properties where optimized by varying the braided structure and different resorbable components. Five different bicomponent structures were fabricated for the stent with different areas and distributions of poly (glycolic acid) (PGA) and poly (lactic-co-glycolic acid) (PLGA) resorbable yarns. Subsequent thermal treatment then converted the PLGA yarns into areas of continuous PLGA polymer film. The morphology, applied compression resistance and recovery and tensile strength tests were conducted on these prototype stents so as to investigate the relationship between their structures and mechanical properties. By selecting the appropriate resorbable biomaterials and altering the design of the braided structure it was possible to generate different sized areas and distributions of 100% braided yarn and 100% polymer film within the same bicomponent tubular structure. The relative total area of braided yarn to polymer film coverage was different for the five different prototype stents as well as between the external and internal surfaces of the bicomponent stents. This relative coverage of the braided yarn to polymer film played an important role in determining the mechanical performance of the stents, including the compression and recovery behavior as well as the tensile properties and failure morphology. The design of Stent C appeared to have the optimal structure for a resorbable ureteral stent with superior applied compression and tensile properties.
可生物吸收输尿管支架具有无需二次取出手术的优势，从而避免了某些并发症。然而，其机械性能不足以及对吸收速率缺乏控制限制了当前原型设计的应用。本文聚焦于一系列可吸收的毫米级支架，这些支架是通过编织和热处理工艺的独特组合制造而成。通过改变编织结构和不同的可吸收组件来优化它们的机械性能。为支架制造了五种不同的双组分结构，其中聚乙醇酸（PGA）和聚乳酸 - 乙醇酸共聚物（PLGA）可吸收纱线的面积和分布各不相同。随后的热处理将PLGA纱线转化为连续的PLGA聚合物膜区域。对这些原型支架进行了形态学、抗压强度及恢复以及拉伸强度测试，以研究其结构与机械性能之间的关系。通过选择合适的可吸收生物材料并改变编织结构设计，有可能在同一双组分管状结构内产生不同尺寸的100%编织纱线和100%聚合物膜的区域及分布。五种不同原型支架以及双组分支架内外表面的编织纱线与聚合物膜覆盖的相对总面积各不相同。编织纱线与聚合物膜的这种相对覆盖率在决定支架的机械性能方面发挥了重要作用，包括压缩和恢复行为以及拉伸性能和失效形态。对于可吸收输尿管支架而言，支架C的设计似乎具有最佳结构，其具有优异的抗压和拉伸性能。
