Bioactive stent surface coating that promotes endothelialization while preventing platelet adhesion.

A bifunctional peptide coating was designed, synthesized, and evaluated as a potential pro-healing stent coating. The bifunctional peptide consisted of a short 28-mer sequence that on the N-terminus has a motif with affinity for polystyrene binding and at the C-terminus has a motif that was shown to bind selectively human endothelial cells but not platelets. Results showed that the selective coating, a polystyrene-binding peptide terminated in RRETAWA (FFSFFFPASAWGSSGSSGK(biotin)CRRETAWAC), bound endothelial cells quantitatively as well as the common RGD motif, but unlike RGD, it did not show any preference for platelet adherence. Follow-up work examining the difference in cell line selectivity between endothelial cells, whose binding should be encouraged, and smooth muscle cells, whose binding should be deprecated in a stenting application, did identify a temporal preference of the RRETAWA-terminated peptide coating for endothelial cells. However, the in vivo implications of this apparent selectivity need to be examined in more detail before definitive conclusions can be drawn. The positive in vitro results encourage the continued development of other novel coatings that mimic biological structures, signaling capabilities, or both to direct cellular processes on the surface of synthetic materials.