Immobilization of Peptide Aptamer of Specific Indentification of Endothelial Progenitor Cell on Titanium Surface

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 bonded to the titanium surface.This peptide aptamer modified surface shows a promising application for vascular devices.

在鈦表面固定可與循環血液中的內皮祖細胞(EPC)特異性結合的多肽適配子,構建內皮祖細胞的特異性識別表面,用于心血管材料的表面改性.首先,采用固相合成法合成可與EPC特異性結合的多肽適配子,其序列為TPSLEQRTVYAK,并在羧基端進行生物素修飾;然后,采用磷酸處理鈦表面,在鈦表面獲得化學鍵合的羥基,該羥基化表面與3-氨丙基三乙氧基硅烷反應,在鈦表面獲得游離的氨基,進一步通過碳二亞胺(EDC)介導,在鈦表面接枝上生物素;最后,通過生物素-親和素識別體系,實現EPC特異性多肽適配子在鈦表面的固定.采用場發射掃描電子顯微鏡(SEM)、漫反射紅外光譜(DR-FTIR)和免疫熒光分析等手段對樣品進行了表征.本研究為多肽適配子在材料表面的固定提供了一種有效的方法,為進一步的生物醫學應用研究提供了基礎.