LAUSR

Metallic materials are used for clinical medical devices such as vascular stents and coils to treat both ischemic and hemorrhagic vascular diseases. Anti-platelet drug is required to avoid thromboembolic complication until metallic surface is covered with neo-endothelial cell layer. It is important to identify endothelial cell coverage on the metallic surface. However, it is difficult since there are no selective ligands. Here, we used phage display method to identify peptide ligands which had high affinity for the metallic surface of Ni-Ti stents, Pt-W coils and Co-Cr stents. The binding assay using fluorescence labelling revealed that several synthetic peptides could bind onto those surfaces. We also chose some oligopeptides for the conjugation onto super paramagnetic iron oxide (SPIO) nanoparticles and liposome encapsulating SPIO nanoparticles, and studied their ability to bind to the stent and coils. By SEM and fluorophotometry, we found that those modified SPIOs and liposomes were selectively bound onto those surfaces. In addition, both treated stents and coils could be detected by magnetic resonance imaging due to the magnetic artifact through the SPIOs and liposomes that were immobilized onto the surface. Thus, we identified metal-binding peptides, which may enable to stop anti-platelet therapy after vascular stenting or coiling.