Fabrication and in vitro deployment of a laser-activated shape memory polymer vascular stent

Géraldine M. Baer, Ward Small IV, Thomas S. Wilson, William J. Benett, Dennis L Matthews, Jonathan Hartman, Duncan J. Maitland

Research output: Contribution to journalArticle

85 Citations (Scopus)

Abstract

Background: Vascular stents are small tubular scaffolds used in the treatment of arterial stenosis (narrowing of the vessel). Most vascular stents are metallic and are deployed either by balloon expansion or by self-expansion. A shape memory polymer (SMP) stent may enhance flexibility, compliance, and drug elution compared to its current metallic counterparts. The purpose of this study was to describe the fabrication of a laser-activated SMP stent and demonstrate photothermal expansion of the stent in an in vitro artery model. Methods: A novel SMP stent was fabricated from thermoplastic polyurethane. A solid SMP tube formed by dip coating a stainless steel pin was laser-etched to create the mesh pattern of the finished stent. The stent was crimped over a fiber-optic cylindrical light diffuser coupled to an infrared diode laser. Photothermal actuation of the stent was performed in a water-filled mock artery. Results: At a physiological flow rate, the stent did not fully expand at the maximum laser power (8.6 W) due to convective cooling. However, under zero flow, simulating the technique of endovascular flow occlusion, complete laser actuation was achieved in the mock artery at a laser power of ∼8 W. Conclusion: We have shown the design and fabrication of an SMP stent and a means of light delivery for photothermal actuation. Though further studies are required to optimize the device and assess thermal tissue damage, photothermal actuation of the SMP stent was demonstrated.

Original languageEnglish (US)
Article number43
JournalBioMedical Engineering Online
Volume6
DOIs
StatePublished - Nov 27 2007

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Stents
Shape memory effect
Blood Vessels
Polymers
Lasers
Fabrication
Arteries
In Vitro Techniques
Light
Semiconductor Lasers
Endovascular Procedures
Polyurethanes
Balloons
Stainless Steel
Scaffolds
Thermoplastics
Fiber optics
Compliance
Semiconductor lasers
Pathologic Constriction

ASJC Scopus subject areas

  • Biomedical Engineering
  • Biophysics
  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging
  • Biomaterials

Cite this

Fabrication and in vitro deployment of a laser-activated shape memory polymer vascular stent. / Baer, Géraldine M.; Small IV, Ward; Wilson, Thomas S.; Benett, William J.; Matthews, Dennis L; Hartman, Jonathan; Maitland, Duncan J.

In: BioMedical Engineering Online, Vol. 6, 43, 27.11.2007.

Research output: Contribution to journalArticle

Baer, Géraldine M. ; Small IV, Ward ; Wilson, Thomas S. ; Benett, William J. ; Matthews, Dennis L ; Hartman, Jonathan ; Maitland, Duncan J. / Fabrication and in vitro deployment of a laser-activated shape memory polymer vascular stent. In: BioMedical Engineering Online. 2007 ; Vol. 6.
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