• thrombogenicity;
  • covered stents;
  • in vitro testing;
  • restenosis;
  • polyvinyl alcohol cryogel


Covered stents may be able to prevent both thrombosis and restenosis, but new mechanically suitable and biocompatible materials are needed before this treatment option can become a reality. Hydrophilic polyvinyl alcohol (PVA) cryogels have desirable mechanical properties for covered stent membranes and may be able to provide a physical barrier to restenosis with low thrombogenicity. An in vitro flow loop with porcine blood was used to compare thrombus formation on different blood-contacting biomaterials. PVA cryogels were found to maintain blood flow with low thrombogenicity and were significantly less thrombogenic than polyester (p < 0.05). The ability to prevent hyperplasic in-growth was evaluated using a modified Boyden chamber cellular migration assay. PVA cryogel membranes used as a physical barrier were found to nearly eliminate cellular migration (p < 0.05) without cellular toxicity. Overall, this article demonstrates pivotal feasibility results for a covered stent membrane material that could prevent restenosis by means of a hydrogel barrier with low thrombogenicity. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.