In vivo and in vitro evaluation of a biodegradable magnesium vascular stent designed by shape optimization strategy
Name
nihms-1537424.pdf
Description
Accepted version
Size
3.54 MB
Format
Adobe PDF
Checksum (MD5)
6e64de683e753878b9183573e043aff6
Author(s)
Chen, Chenxin
Chen, Jiahui
Wu, Wei
Shi, Yongjuan
Jin, Liang
Petrini, Lorenza
Shen, Li
Yuan, Guangyin
Ding, Wenjiang
Ge, Junbo
Date Issued
November 2019
Journal
Biomaterials
Publisher
Elsevier BV
Citation
Chen, Chenxin et al. "In vivo and in vitro evaluation of a biodegradable magnesium vascular stent designed by shape optimization strategy." Biomaterials 221 (November 2019): 119414 © 2019 Elsevier Ltd
Version
Author's final manuscript
Abstract
The performance of biodegradable magnesium alloy stents (BMgS) requires special attention to non-uniform residual stress distribution and stress concentration, which can accelerate localized degradation after implantation. We now report on a novel concept in stent shape optimization using a finite element method (FEM) toolkit. A Mg-Nd-Zn-Zr alloy with uniform degradation behavior served as the basis of our BMgS. Comprehensive in vitro evaluations drove stent optimization, based on observed crimping and balloon inflation performance, measurement of radial strength, and stress condition validation via microarea-XRD. Moreover, a Rapamycin-eluting polymer coating was sprayed on the prototypical BMgS to improve the corrosion resistance and release anti-hyperplasia drugs. In vivo evaluation of the optimized coated BMgS was conducted in the iliac artery of New Zealand white rabbit with quantitative coronary angiography (QCA), optical coherence tomography (OCT) and micro-CT observation at 1, 3, 5-month follow-ups. Neither thrombus or early restenosis was observed, and the coated BMgS supported the vessel effectively prior to degradation and allowed for arterial healing thereafter. The proposed shape optimization framework based on FEM provides an novel concept in stent design and in-depth understanding of how deformation history affects the biomechanical performance of BMgS. Computational analysis tools can indeed promote the development of biodegradable magnesium stents.
MIT Department
Massachusetts Institute of Technology. Institute for Medical Engineering & Science
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
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DOI of Published Version
https://doi.org/10.1016/j.biomaterials.2019.119414
