title: The BioStent: novel concept for a viable stent structure.
abstract: OBJECTIVE
  Percutaneous stenting of occluded peripheral vessels is a well-established technique in clinical practice. Unfortunately, the patency rates of small-caliber vessels after stenting remain unsatisfactory. The aim of the BioStent concept is to overcome in-stent restenosis by excluding the diseased vessel segment entirely from the blood stream, in addition to providing an intact endothelial cell layer.
  
  
  METHODS
  The concept combines the principles of vascular tissue engineering with a self-expanding stent: casting of the stent within a cellularized fibrin gel structure, followed by bioreactor conditioning, allows complete integration of the stent within engineered tissue.
  
  
  METHODS
  Small-caliber BioStents (Ø=6 mm; n=4) were produced by casting a nitinol stent within a thin fibrin/vascular smooth muscle cell (vSMC) mixture, followed by luminal endothelial cell seeding, and conditioning of the BioStent within a bioreactor system. The potential remodeling of the fibrin component into tissue was analyzed using routine histological methods. Scanning electron microscopy was used to assess the luminal endothelial cell coverage following the conditioning phase and crimping of the stent.
  
  
  RESULTS
  The BioStent was shown to be noncytotoxic, with no significant effect on cell proliferation. Gross and microscopic analysis revealed complete integration of the nitinol component within a viable tissue structure. Hematoxylin and eosin staining revealed a homogenous distribution of vSMCs throughout the thickness of the BioStent, while a smooth, confluent luminal endothelial cell lining was evident and not significantly affected by the crimping/release process.
  
  
  CONCLUSIONS
  The BioStent concept is a platform technology offering a novel opportunity to generate a viable, self-expanding stent structure with a functional endothelial cell lining. This platform technology can be transferred to different applications depending on the luminal cell lining required.
authors.affiliation: Department of Tissue Engineering & Textile Implants, AME-Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Weinandy
authors.forename: Lisanne
authors.initials: L
authors.lastname: Rongen
authors.forename: Fabian
authors.initials: F
authors.lastname: Schreiber
authors.forename: Christian
authors.initials: C
authors.lastname: Cornelissen
authors.forename: Thomas Cormac
authors.initials: TC
authors.lastname: Flanagan
authors.forename: Andreas
authors.initials: A
authors.lastname: Mahnken
authors.forename: Thomas
authors.initials: T
authors.lastname: Gries
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmitz-Rode
authors.forename: Stefan
authors.initials: S
authors.lastname: Jockenhoevel
mesh_terms: D000497:Alloys / Q000494:pharmacology; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D019149:Bioreactors; D002339:Carotid Arteries / Q000166:cytology / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D017076:Computer-Aided Design; D004727:Endothelium / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D008855:Microscopy, Electron, Scanning; D011474:Prosthesis Design; D012756:Sheep; D015607:Stents; D023822:Tissue Engineering
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; C013616:nitinol