Abstract: In vivo spontaneous endothelialization of cardiovascular materials is thought to be a promising approach to prevent the formation of thrombus and restenosis. Capturing endothelial progenitor cells (EPC) from blood and inducing EPC to grow on the surface of stents is a new strategy for this purpose. In this study，we developed a facile and effective approach to construct a surface that possessed a high affinity and specificity to EPCs by binding peptide aptamer. In order to introduce primary amine groups to covalently immobilize biotin，the titanium surface was treated by phosphoric acid solution to obtain the hydroxyl groups which were used to covalently immobilize aminopropyltriethoxysilane. Furthermore，the biotin was grafted onto the amine functionalized titanium surface by carbodiimide (EDC)-mediated. Finally，using layer-by-layer self-assembly method，biotinylated peptide aptamer was fixed on the titanium surface by the biotin-avidin recognition system. The results of fourier transform infrared spectroscopy (FTIR)，fluorescence labeling method and scanning electron microscopy (SEM) demonstrated that peptide aptamer was successfully bond to the titanium surface. This peptide aptamer modified surface shows a promising application for vascular devices.

Key words: EPC-specific peptide, endothelial progenitor cell, titanium, surface modification