Tirofiban Positively Regulates β1 Integrin and Favours Endothelial Cell Growth on Polylactic Acid Biopolymer Vascular Scaffold (BVS).

An unexpectedly high incidence of thrombosis in patients that received the polylactic acid bioresorbable vascular scaffold (BVS) suggests a delayed/incomplete endothelial repair with this stent. The anti-platelet agent tirofiban stimulates endothelial cell migration and proliferation, mediated by VEGF production. We investigated the tirofiban effect on the migration and adhesion of endothelial cells to BVS, in vitro. We performed human umbilical endothelial cell (HUVEC) cultures in the presence of BVS. Tirofiban, similarly to VEGF, increased the ability of HUVEC to grow on the vascular scaffold, compared to unstimulated or abciximab-treated cells. Tirofiban increased HUVEC expression of β1 and β3 integrins along with collagen and fibronectin. A role for β1 integrin in the "pro-adhesive and -migratory" signals elicited by tirofiban was suggested by use of an anti-β1-blocking antibody that prevented poly-levo-lactic acid vascular scaffold colonization. Our study suggests that tirofiban may improve the outcomes of patients receiving BVS by accelerating stent endothelization.