Radial Compressive Property and the Proof-of-Concept Study for Realizing Self-expansion of 3D Printing Polylactic Acid Vascular Stents with Negative Poisson's Ratio Structure

Zichao Wu; Ji Zhao; Wenzheng Wu; Peipei Wang; Bofan Wang; Guiwei Li; Shuo Zhang

doi:10.3390/ma11081357

Radial Compressive Property and the Proof-of-Concept Study for Realizing Self-expansion of 3D Printing Polylactic Acid Vascular Stents with Negative Poisson's Ratio Structure

Materials (Basel). 2018 Aug 6;11(8):1357. doi: 10.3390/ma11081357.

Authors

Zichao Wu¹, Ji Zhao², Wenzheng Wu³, Peipei Wang⁴, Bofan Wang⁵, Guiwei Li⁶, Shuo Zhang⁷

Affiliations

¹ School of Mechanical and Aerospace Engineering, Jilin University, Changchun 130025, China. wuzc15@mails.jlu.edu.cn.
² School of Mechanical and Aerospace Engineering, Jilin University, Changchun 130025, China. jzhao@jlu.edu.cn.
³ School of Mechanical and Aerospace Engineering, Jilin University, Changchun 130025, China. wzwu@jlu.edu.cn.
⁴ School of Mechanical and Aerospace Engineering, Jilin University, Changchun 130025, China. wangpe1_i@163.com.
⁵ School of Mechanical and Aerospace Engineering, Jilin University, Changchun 130025, China. wangbf1415@mails.jlu.edu.cn.
⁶ School of Mechanical and Aerospace Engineering, Jilin University, Changchun 130025, China. ligw15@mails.jlu.edu.cn.
⁷ School of Mechanical and Aerospace Engineering, Jilin University, Changchun 130025, China. zhangshuo028@jlu.edu.cn.

Abstract

Biodegradable stents offer the potential to reduce the in-stent restenosis by providing support long enough for the vessel to heal. The polylactic acid (PLA) vascular stents with negative Poisson's ratio (NPR) structure were manufactured by fused deposition modeling (FDM) 3D printing in this study. The effects of stent diameter, wall thickness and geometric parameters of arrowhead NPR structure on radial compressive property of 3D-printed PLA vascular stent were studied. The results showed that the decrease of stent diameter, the increase of wall thickness and the increase of the surface coverage could enhance the radial force (per unit length) of PLA stent. The radial and longitudinal size of PLA stent with NPR structure decreased simultaneously when the stent was crimped under deformation temperature. The PLA stent could expand in both radial and longitudinal direction under recovery temperature. When the deformation temperature and recovery temperature were both 65 °C, the diameter recovery ratio of stent was more than 95% and the maximum could reach 98%. The length recovery ratio was above 97%. This indicated the feasibility of utilizing the shape memory effect (SME) of PLA to realize the expansion of 3D-printed PLA vascular stent under temperature excitation.

Keywords: 3D printing; negative Poisson’s ratio; polylactic acid; shape memory effect; vascular stent.