Qi Pengkai, Yan Wei, Yang Ying, Li Yalong, Fan Yi, Chen Junying, Yang Zhilu, Tu Qiufen, Huang Nan
Key Lab of Advanced Technology of Materials of Education Ministry, Southwest Jiaotong University, Chengdu 610031, China; School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
Key Lab of Advanced Technology of Materials of Education Ministry, Southwest Jiaotong University, Chengdu 610031, China; Laboratory of Biosensing and MicroMechatronics, Southwest Jiaotong University, Chengdu 610031, China.
Colloids Surf B Biointerfaces. 2015 Feb 1;126:70-9. doi: 10.1016/j.colsurfb.2014.12.001. Epub 2014 Dec 9.
The endothelial progenitor cells (EPCs) capture stent has drawn increasing attentions and become one of the most promising concepts for the next generation vascular stent. In this regard, it is of great significance to immobilize a molecule with the ability to bind EPC for rapid in vivo endothelialization with high specificity. In this work, a facile two-step method aimed at constructing a coating with specific EPC capturing aptamers is reported. The processes involves as the first-step deposition of plasma polymerized allylamine (PPAam) on a substrate to introduce amine groups, followed by the electrostatic adsorption of a 34 bases single strand DNA sequence to the PPAam surface as a second step (PPAam-DNA). Grazing incidence attenuated total reflection Fourier transform infrared spectroscopy (GATR-FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the successful immobilization of the aptamers. Quartz crystal microbalance with dissipation (QCM-D) real time monitoring result shows that about 175 ng/cm(2) aptamers were conjugated onto the PPAam surface. The interactions between the modified surfaces and human umbilical vein endothelial cells (ECs), smooth muscle cells (SMCs), and murine induced EPCs derived from mesenchymal stem cells (MSCs) were also investigated. It was demonstrated that PPAam-DNA samples could capture more EPCs, and present a cellular friendly surface for the proliferation of both EPCs and ECs but no effect on the hyperplasia of SMCs. Also, the co-culture results of 3 types of cells confirmed that the aptamer could specifically bond EPCs rather than ECs and SMCs, suggesting the competitive adhesion advantage of EPCs to ECs and SMCs. These data demonstrate that the EPC aptamer has large potential for designing an EPC captured stent and other vascular grafts with targeted in situ endothelialization.
内皮祖细胞（EPC）捕获支架已引起越来越多的关注，并成为下一代血管支架最具前景的概念之一。在这方面，固定一种具有结合EPC能力的分子对于在体内快速实现高特异性内皮化具有重要意义。在这项工作中，报道了一种简便的两步法，旨在构建具有特异性EPC捕获适体的涂层。该过程包括第一步在基底上沉积等离子体聚合烯丙胺（PPAam）以引入胺基，第二步将34个碱基的单链DNA序列静电吸附到PPAam表面（PPAam-DNA）。掠入射衰减全反射傅里叶变换红外光谱（GATR-FTIR）和X射线光电子能谱（XPS）证实了适体的成功固定。石英晶体微天平耗散监测（QCM-D）实时监测结果表明，约175 ng/cm²的适体共轭到PPAam表面。还研究了修饰表面与人类脐静脉内皮细胞（ECs）、平滑肌细胞（SMCs）以及源自间充质干细胞（MSCs）的小鼠诱导EPC之间的相互作用。结果表明，PPAam-DNA样品可以捕获更多的EPC，并为EPC和ECs增殖提供细胞友好表面，但对SMCs增生没有影响。此外，三种细胞的共培养结果证实，适体可以特异性结合EPC而不是ECs和SMCs，表明EPC相对于ECs和SMCs具有竞争粘附优势。这些数据表明，EPC适体在设计具有靶向原位内皮化的EPC捕获支架和其他血管移植物方面具有巨大潜力。
