title: Optimization of Drug Delivery by Drug-Eluting Stents.
abstract: Drug-eluting stents (DES), which release anti-proliferative drugs into the arterial wall in a controlled manner, have drastically reduced the rate of in-stent restenosis and revolutionized the treatment of atherosclerosis. However, late stent thrombosis remains a safety concern in DES, mainly due to delayed healing of the endothelial wound inflicted during DES implantation. We present a framework to optimize DES design such that restenosis is inhibited without affecting the endothelial healing process. To this end, we have developed a computational model of fluid flow and drug transport in stented arteries and have used this model to establish a metric for quantifying DES performance. The model takes into account the multi-layered structure of the arterial wall and incorporates a reversible binding model to describe drug interaction with the cells of the arterial wall. The model is coupled to a novel optimization algorithm that allows identification of optimal DES designs. We show that optimizing the period of drug release from DES and the initial drug concentration within the coating has a drastic effect on DES performance. Paclitaxel-eluting stents perform optimally by releasing their drug either very rapidly (within a few hours) or very slowly (over periods of several months up to one year) at concentrations considerably lower than current DES. In contrast, sirolimus-eluting stents perform optimally only when drug release is slow. The results offer explanations for recent trends in the development of DES and demonstrate the potential for large improvements in DES design relative to the current state of commercial devices.
authors.affiliation: Laboratoire d'Hydrodynamique (LadHyX), École Polytechnique-CNRS, Palaiseau cedex, France.
authors.forename: Franz
authors.initials: F
authors.lastname: Bozsak
authors.affiliation: Laboratoire d'Hydrodynamique (LadHyX), École Polytechnique-CNRS, Palaiseau cedex, France.
authors.forename: David
authors.initials: D
authors.lastname: Gonzalez-Rodriguez
authors.affiliation: Laboratoire d'Hydrodynamique (LadHyX), École Polytechnique-CNRS, Palaiseau cedex, France.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Sternberger
authors.affiliation: UCSD Flow Control and Coordinated Robotics Labs Dept of MAE, UC San Diego, La Jolla, CA, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Belitz
authors.affiliation: UCSD Flow Control and Coordinated Robotics Labs Dept of MAE, UC San Diego, La Jolla, CA, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bewley
authors.affiliation: Laboratoire d'Hydrodynamique (LadHyX), École Polytechnique-CNRS, Palaiseau cedex, France.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Chomaz
authors.affiliation: Laboratoire d'Hydrodynamique (LadHyX), École Polytechnique-CNRS, Palaiseau cedex, France.
authors.forename: Abdul I
authors.initials: AI
authors.lastname: Barakat
mesh_terms: D000465:Algorithms; D050197:Atherosclerosis / Q000378:metabolism / Q000503:physiopathology; D001692:Biological Transport; D003251:Constriction, Pathologic / Q000209:etiology; D016503:Drug Delivery Systems / Q000009:adverse effects / Q000379:methods*; D054855:Drug-Eluting Stents / Q000009:adverse effects; D004730:Endothelium, Vascular / Q000378:metabolism; D008954:Models, Biological; D017239:Paclitaxel / Q000008:administration & dosage / Q000378:metabolism; D011474:Prosthesis Design / Q000379:methods*; D017540:Tunica Media / Q000378:metabolism / Q000503:physiopathology; D014945:Wound Healing
chemical_list: D017239:Paclitaxel