Mechanical properties of a biodegradable self-expandable polydioxanone monofilament stent: In vitro force relaxation and its clinical relevance

PLoS One. 2020 Jul 8;15(7):e0235842. doi: 10.1371/journal.pone.0235842. eCollection 2020.

Abstract

Biodegradable stents are promising treatments for many diseases, e.g., coronary artery disease, urethral diseases, tracheal diseases, and esophageal strictures. The mechanical properties of biodegradable stent materials play a key role in the safety and efficacy of treatment. In particular, insufficient creep resistance of the stent material could result in premature stent collapse or narrowing. Commercially available biodegradable self-expandable SX-ELLA stents made of polydioxanone monofilament were tested. A new, simple, and affordable method to measure the shear modulus of tiny viscoelastic wires is presented. The important mechanical parameters of the polydioxanone filament were obtained: the median Young's modulus was [Formula: see text] = 958 (922, 974) MPa and the shear modulus was [Formula: see text] = 357 (185, 387) MPa, resulting in a Poisson's ratio of ν = 0.34. The SX-ELLA stents exhibited significant force relaxation due to the stress relaxation of the polydioxanone monofilament, approximately 19% and 36% 10 min and 48 h after stent application, respectively. However, these results were expected, and the manufacturer and implanting clinician should be aware of the known behavior of these biodegradable materials. If possible, a biodegradable stent should be designed considering therapeutic force rather than initial force. Additionally, new and more advanced biodegradable shape-memory polymers should be considered for future study and use.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorbable Implants*
  • Biocompatible Materials / chemistry*
  • Elastic Modulus
  • Humans
  • Materials Testing
  • Mechanical Phenomena
  • Polydioxanone / chemistry*
  • Prosthesis Design
  • Stents*

Substances

  • Biocompatible Materials
  • Polydioxanone

Grants and funding

We acknowledge the financial support from the Ministry of Education, Youth and Sports of the Czech Republic: o programme UK PROGRES Q40-09 o project LQ1601 o project CZ.02.1.01/0.0/0.0/17_048/0007421 o project LM2018103 Authors who received salaries from the funder: programme UK PROGRES Q40-09: Ales Bezrouk, Martin Kopecek, Iva Selke Krulichova project LQ1601: Jan Macak project CZ.02.1.01/0.0/0.0/17_048/0007421: Ales Bezrouk, Ludek Hromadko, Jan Macak project LM2018103: Jan Macak, Ludek Hromadko, Zuzana Olmrova Zmrhalova The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.