In vitro evaluation of vascular endothelial growth factor (VEGF)-eluting stents.

Background: Vascular endothelial growth factor (VEGF) is a specific endothelial cell mitogen. It promotes re-endothelialisation of the damaged vessel surface seen after stenting. Stent thrombosis and in-stent restenosis are partly related to endothelial denudation caused by stent implantation. We propose using hydrocarbon polymer-coated stents immersed in VEGF to speed re-endothelialisation and reduce the risk of stent thrombosis and restenosis. Methods: Stents (3×20 mm) were immersed in VEGF solutions and maximal VEGF absorption calculated. VEGF release from these stents was measured in a perfusion circuit. Delivery of VEGF to arterial wall was measured. Sterile VEGF-loaded stents were cultured with human umbilical vein endothelial cells. Results: 18.5±4.1 μg VEGF was absorbed, 80% of which was released over 9 days; 11±6.8% of the initial VEGF loaded was delivered to the vessel wall. Cells exposed to VEGF-eluting stents showed an 11% increase in growth relative to controls. Conclusion: VEGF may be a candidate for stent-based delivery and may increase the rate of endothelialisation in vivo.