Ti表面构建Ⅳ型胶原/肝素生物层提高细胞相容性的研究

Immobilization heparin/type Ⅳ collagen onto titanium surface for improving the biocompatibility

支架表面内皮化成为最终实现支架与血液及组织长期相容的良好途径,内皮祖细胞在材料表面的集聚、生长与增殖使快速内皮化成为可能。利用静电结合作用将抗凝血药物肝素和内皮细胞基膜中重要组成的Ⅳ型胶原结合到Ti表面,使其具有良好的细胞相容性。Ti通过碱活化和硅烷化处理后,形成带正电荷的氨基表面,与有残留负电荷的肝素/Ⅳ型胶原复合物静电结合,形成生物化层。通过傅立叶红外掠射检测了材料表面特征基团的变化,通过水接触角的测定和扫描电子显微镜跟踪表面亲疏水性能以及表面形貌的变化。通过免疫荧光染色法对Ⅳ型胶原进行定性表征。结果显示仿生层构建成功,修饰后的表面较Ti表面能够粘附更多的内皮祖细胞,细胞生长与增殖较快,且细胞形态良好,细胞相容性得到明显改善。Ⅳ型胶原的引入对于心血管植入器械的表面改性有重要参考价值。

Endothelialization is a good way to obtain ultimate long-term compatibility of the interfaces between stents and blood or/and tissue.Rapid endothelialization on the biomaterials surface is possible through the aggregation,growth and proliferation of endothelial progenitor cells.In this paper,the anti-clotting drug of heparin and type Ⅳ collagen as a main component of basement membrane were combined onto the titanium surface to improve the biocompatibility.The formation of positively charged amino surface on titanium was firstly completed after alkali activation and silane treatment.The residual negative charges of heparin/type Ⅳ collagen complex were then combined to the positively charged amino surface via electrostatic interaction.The change of the groups on the surface was detected by the Fourier transform infrared spectroscopy.The water contact angle measurement and scanning electron microscopy were used to track the surface hydrophilic and hydrophobic properties and surface morphology changes.Qualitative characterization of type Ⅳ collagen and the morphology of endothelial progenitor cells were detected by immunofluorescence staining.The results showed that the bioinspired layer was successfully constructed.In compared with titanium,the bionic modified surface had more endothelial progenitor cells（EPCs） adhesion,more rapid cell growth and proliferation,and better cell morphology.It was concluded that the cell compatibility was significantly improved due to the biological modification on materials surface.The introductions of type Ⅳ collagen to materials surface provide an important pathway for the surface modification of cardiovascular implants.