Department of Polymer Science and Engineering, Key Laboratory of Macromolecule Synthesis and Functionalization of the Ministry of Education, Zhejiang University, Hangzhou, China.
Biomaterials. 2010 May;31(14):4017-25. doi: 10.1016/j.biomaterials.2010.01.092. Epub 2010 Feb 9.
The in-stent restenosis (ISR) and the late stent thrombosis (LAST) represent the most common failures of stent implantation and are both mediated at the injured endothelium. The natural endothelium healing mechanism provides an approach to achieve in situ endothelialization of the implant by stimulating the neighboring endothelial cells (ECs) migration or capturing the circulating endothelial cells (CEC) directly from the blood circulation. An anti-CD34 antibody functionalized multilayer of heparin/collagen is developed here via layer-by-layer assemble. The ellipsometry and QCM-D results demonstrate that the multilayer coatings with slight glutaraldehyde cross-linking are stable in static incubation and flushing conditions, respectively. The in vitro hemocompatibility tests and cell culture results indicate that both heparin/collagen multilayers with or without the anti-CD34 antibody functionalization not only preserve good hemocompatibility, but also promote cell attachment and growth notably. While the heparin/collagen multilayer coatings show no selectivity in promotion of ECs and smooth muscle cells (SMCs), the anti-CD34 antibody functionalized heparin/collagen multilayers can specifically promote the attachment and growth of the vascular ECs. The metabolic activity assessment and the NO secretion measurements further indicate that the adherent ECs on the anti-CD34 antibody functionalized heparin/collagen multilayer surface have better viability and possess the specific function of the natural vascular ECs. In vivo experiments indicate that the anti-CD34 antibody can enrich and accelerate the attachment of the vascular cells onto the stent and rapid endothelialization is realized. While no significant difference of neointimal hyperplasia is observed between the bare metal stents and heparin/collagen multilayer modified stents, the neointimal hyperplasia on the anti-CD34 antibody functionalized multilayer modified stents is significantly inhibited. The success of the anti-CD34 antibody functionalized heparin/collagen multilayer coating in rapid endothelialization and anti-restenosis might indicate that the immobilization of ECs specific ligand onto a cytocompatible matrix can be a good approach for in situ endothelialization and a possible solution to ISR.
支架内再狭窄（ISR）和晚期支架内血栓形成（LAST）是支架植入后最常见的失败类型，这两种情况都是由损伤的血管内皮介导的。天然的血管内皮愈合机制为实现植入物的原位内皮化提供了一种方法，即通过刺激相邻的内皮细胞（ECs）迁移或直接从血液循环中捕获循环内皮细胞（CEC）。本文通过层层组装开发了一种抗 CD34 抗体功能化的肝素/胶原多层膜。通过椭圆偏振法和石英晶体微天平（QCM-D）的结果表明，轻微戊二醛交联的多层涂层在静态孵育和冲洗条件下均稳定。体外血液相容性测试和细胞培养结果表明，具有或不具有抗 CD34 抗体功能化的肝素/胶原多层膜不仅保持良好的血液相容性，而且还能显著促进细胞附着和生长。虽然肝素/胶原多层膜在促进 ECs 和平滑肌细胞（SMCs）方面没有选择性，但抗 CD34 抗体功能化的肝素/胶原多层膜可以特异性地促进血管 ECs 的附着和生长。代谢活性评估和 NO 分泌测量进一步表明，在抗 CD34 抗体功能化的肝素/胶原多层膜表面附着的 ECs 具有更好的活力，并具有天然血管 ECs 的特定功能。体内实验表明，抗 CD34 抗体可以富集并加速血管细胞附着在支架上，并实现快速内皮化。虽然在裸金属支架和肝素/胶原多层改性支架之间未观察到新生内膜过度增生的显著差异，但在抗 CD34 抗体功能化的多层改性支架上的新生内膜过度增生显著受到抑制。抗 CD34 抗体功能化的肝素/胶原多层涂层在快速内皮化和抗再狭窄方面的成功可能表明，将 ECs 特异性配体固定在细胞相容性基质上可能是实现原位内皮化的一种很好的方法，也是解决 ISR 的一种可能的解决方案。
