Effects of annealing temperature on both radial supporting performance and axial flexibility of poly(L‐lactic acid) braided stents
Effects of annealing temperature on both radial supporting performance and axial flexibility of poly(L‐lactic acid) braided stents
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DOI：
10.1002/app.50517
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发表时间：
2021-02
影响因子：
3
通讯作者：
Yuan Tian;Muqing Liu;Wentao Liu;Jie Cheng;Gensheng Wu;Tingting Han;Yi Zhang;Gutian Zhao
中科院分区：
文献类型：
--
作者：
Yuan Tian;Muqing Liu;Wentao Liu;Jie Cheng;Gensheng Wu;Tingting Han;Yi Zhang;Gutian Zhao
本文研究了退火温度对聚乳酸（PLLA）编织支架径向支撑性能和轴向柔性的影响。将支架在80 ~ 160℃的一系列温度下退火1 h，然后比较成型效果、径向支撑性能和轴向柔韧性指标。未退火和80℃退火的支架不能完全成形。相比之下，在100 ~ 160℃退火的支架形状良好，径向收缩率为1.0±0.2%，几乎没有轴向伸长率。从80℃到160℃，随着退火温度的逐渐升高，径向压缩力和轴向力分别逐渐增大51.2%和89.2%，表明较高的退火温度提高了径向支撑性能，但削弱了轴向柔韧性。综上所述，PLLA编织支架可以在100 ~ 120℃退火，同时获得足够的径向力和较低的轴向力，用于临床应用。此外，通过对不同退火温度下单丝的拉伸试验、X射线衍射和差示扫描量热法，进一步探讨了退火温度对支架力学性能的影响机理。本研究为生物可降解编织支架的研制提供了有益的建议。
In this paper, the effects of annealing temperature on both radial supporting performance and axial flexibility of poly(L‐lactic acid) (PLLA) braided stents are studied. Stents are annealed at a series of temperatures ranging from 80 to 160°C for 1 h, then indicators of shaping effect, radial supporting performance, and axial flexibility are compared. Stents not annealed and annealed at 80°C cannot be completely shaped. In contrast, stents annealed at 100 to 160°C are well shaped showing radial shrinkage rate of 1.0 ± 0.2% and almost no axial elongation. The radial compressive force and axial force are gradually increased by 51.2% and 89.2%, respectively with the annealing temperature gradually increasing from 80 to 160°C, indicating that the radial supporting performance is improved but axial flexibility is weakened by a higher annealing temperature. Taken together, PLLA braided stents can be annealed at 100 to 120°C to obtain sufficient radial force and lower axial force simultaneously for clinical applications. Moreover, tensile test, X‐ray diffraction, and differential scanning calorimetry are performed for monofilaments annealed at different temperatures to further explore the effect mechanism of annealing temperature on the mechanical properties of stents. This study may provide helpful suggestions for the manufacture of biodegradable braided stents.