AUXETIC DRUG-ELUTING STENT DESIGN

摘要

A cardiovascular stent is a cylindrical wire mesh structure that is permanently introduced into an artery during angioplasty (balloon dilatation) to act as a scaffold, thus preventing elastic recoil and/or sudden collapse of the damaged artery. While cardiovascular stents virtually eliminate elastic recoil and/or collapse of the artery, recognition of the stent as a foreign material triggers a human immune system response causing re-closure, or restenosis, of the artery. A recent advancement to counteract restenosis is to employ drug-eluting stents to locally deliver immunosuppressant and antiproliferative drugs. Two aspects of drug-eluting stent design are analytically addressed in this paper. Fick's law of diffusion was used to model the diffusion of immunosuppressant and antiproliferative drugs from the stent into the adjacent arterial tissue. Also, an analytical procedure was developed to estimate the circumferential and the flexural stiffnesses of stents. Furthermore, a unique auxetic (negative Poisson's ratio) stent structure is proposed that exhibits high circumferential strength in its expanded configuration and low flexural rigidity in its crimped configuration.