Development of mussel adhesive polypeptide mimics coating for in-situ inducing re-endothelialization of intravascular stent devices

In this study, to improve the attachment, growth and adhesion of endothelial cells (ECs) and thus accelerate the re-endothelialization of stents, a synthesized mussel adhesive polypeptide mimics containing dihydroxyphenylalanine and l-lysine (MAPDL) was immobilized onto 316L stainless steel (316LSS) with polyethylene glycol (PEG) molecule as spacer arm by using cold plasma-induced grafting technique. To immobilize MAPDL effectively, ethylene vinyl acetate (EVA) was first coated onto 316LSS. Different molecular weights of PEG and grafting times were tested to obtain the optimal cell bioactivity. XPS and water contact angles measurement indicated the successful immobilization of MAPDL. In vitro cell culture results showed that compared with the control of 316LSS, the attachment, adhesion and growth of cells on the MAPDL-coated EVA surface, in particular with PEG as spacer arm, were significantly enhanced, and a confluent endothelial cells layer was formed after a 2-day culture. A platelet adhesion experiment revealed that the platelet adhesion was also reduced on the MAPDL-coated EVA surface. The in vitro inflammatory assessment showed that the MAPDL coating inhibited the TNF-α and IL-1β release from monocyte cells, indicative of good anti-inflammation property. Therefore, it is concluded that the MAPDL coating developed here appeared to be a promising strategy for rapid re-endothelialization of intravascular stent devices.