Enhanced Endothelialization of a New Stent Polymer Through Surface Enhancement and Incorporation of Growth Factor-Delivering Microparticles

In this study, we sought to develop strategies for improved endothelialization of a new polymer coating for vascular stents. Surface enhancement of the new poly-1,8-octanediol-co-citric acid (POC) polymer was achieved through conjugation of anti-CD34 antibody and incorporation of vascular endothelial growth factor and basic fibroblast growth factor-containing poly-lactic-co-glycolic acid microparticles to improve capture and proliferation of endothelial progenitor cells (EPC) and compared to untreated POC and poly-L-lactic acid (PLLA) polymer. Our results indicate that compared to PLLA, POC coating was more hemocompatible, with less platelet activation (p = 0.01), thrombogenicity (p < 0.05 for 20 and 30 min clot formation), and inflammatory response (IL-1 beta release, p = 0.0009; TNF-alpha release, p = 0.004). EPC adhesion and proliferation on POC were significantly improved with surface enhancement and microparticle incorporation compared to untreated POC (p = 0.006) and PLLA (p = 0.003). These results suggest a new strategy for enhancing endothelialization of polymeric coatings of vascular prostheses.