钛表面固定特异性识别内皮祖细胞的多肽适配子

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

在钛表面固定可与循环血液中的内皮祖细胞(EPC)特异性结合的多肽适配子,构建内皮祖细胞的特异性识别表面,用于心血管材料的表面改性.首先,采用固相合成法合成可与EPC特异性结合的多肽适配子,其序列为TPSLEQRTVYAK,并在羧基端进行生物素修饰;然后,采用磷酸处理钛表面,在钛表面获得化学键合的羟基,该羟基化表面与3-氨丙基三乙氧基硅烷反应,在钛表面获得游离的氨基,进一步通过碳二亚胺(EDC)介导,在钛表面接枝上生物素;最后,通过生物素-亲和素识别体系,实现EPC特异性多肽适配子在钛表面的固定.采用场发射扫描电子显微镜(SEM)、漫反射红外光谱(DR-FTIR)和免疫荧光分析等手段对样品进行了表征.本研究为多肽适配子在材料表面的固定提供了一种有效的方法,为进一步的生物医学应用研究提供了基础.

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.