反应性羧酸甜菜碱两性离子共聚物构建内皮细胞选择性功能界面研究

发布时间：2018-03-25 14:35

本文选题：心血管支架功能涂层　切入点：原位内皮化　出处：《浙江大学》2012年硕士论文

【摘要】：心血管植入材料在心血管疾病治疗中发挥重要作用的同时,依然面临包括凝血,术后再狭窄等一系列挑战。具有血管原位内皮再生功能的材料是实现心血管组织再生的重要物质基础。由于生命体系的复杂性,构建具有内皮细胞选择性诱导功能的涂层材料,实现复杂体系中血管内皮细胞的选择性诱导是实现血管原位内皮再生功能的关键。含有两性离子基团的化合物,不仅可以明显改善材料的血液相容性,而且可以实现对蛋白质,血小板和细胞的非特异性阻抗,已成为心血管植入材料界面修饰的有效手段之一。而基于羧酸甜菜碱的两性离子聚合物近年来也成为生物材料表面修饰改性的研究热点,其结构与磷酸胆碱基团类似,具有优良的生物抗污性能,且具有更简单的合成方法和稳定性。此外,羧酸甜菜碱表面的羧基可与生物分子的氨基共价键合,为实现界面功能化设计提供了有效手段。本研究以羧酸甜菜碱两性电荷聚合物为基础,设计构建具有良好生物抗污性能和血液相容性的涂层材料,并在涂层表面固定具有内皮细胞选择能力的活性短肽REDV (Arg-Glu-Asp-Val)。探索羧酸甜菜碱基团的非特异性阻抗和REDV短肽的特异性诱导协同作用制备具有内皮细胞选择性功能的涂层设计。研究采用自由基共聚的方法得到了不同亲疏水比例的甲基丙烯酸羧酸甜菜碱酯(CBMA)和甲基丙烯酸正丁酯(BMA)的无规共聚物,通过调节聚合单体组成功制备能稳定存在于基材表面的可功能化涂层,进一步通过NHS/EDC活化涂层表面的羧基,与短肽REDV的氨基反应,将短肽固定在涂层表面。并完成对REDV功能化羧酸甜菜碱共聚物涂层基础理化性质的表征。此外,蛋白质吸附和体外血液相容性实验结果表明,固定短肽后,涂层仍具有明显的抗蛋白质吸附能力,并具有优良的抗凝血、抗血小板吸附能力。本研究着重对人脐静脉内皮细胞(HUVEC)和人脐动脉平滑肌细胞(HUASMC)在REDV功能化羧酸甜菜碱共聚物涂层表面的生长行为进行了表征。细胞粘附和增殖实验结果表明,功能化羧酸甜菜碱共聚物涂层表面的内皮细胞选择性是通过羧酸甜菜碱组分对平滑肌细胞的非特异性阻抗及REDV短肽对内皮细胞的特异性诱导作用共同实现的,羧酸甜菜碱组分的引入,提高了涂层对内皮细胞的选择能力,抑制了平滑肌细胞的生长和迁移。且在较复杂的共培养体系中,这种对内皮细胞的高选择性依然存在。本工作成功构建了具有良好的生物抗污能力、血液相容性及内皮细胞选择性的REDV功能化羧酸甜菜碱共聚物涂层,为进一步将两性甜菜碱聚合物应用于心血管支架表面改性提供了基础。
[Abstract]:While cardiovascular implants play an important role in the treatment of cardiovascular disease, they still face the challenge of including coagulation. A series of challenges such as restenosis after operation. Materials with vascular in situ endothelial regeneration function are the important material basis for cardiovascular tissue regeneration. Due to the complexity of life system, the coating material with selective induction function of endothelial cells is constructed. Selective induction of vascular endothelial cells in complex systems is the key to the function of vascular in situ endothelial regeneration. Compounds containing amphoteric groups can not only significantly improve the blood compatibility of the materials, but also achieve proteins. Non-specific impedance of platelets and cells has become one of the effective methods for interfacial modification of cardiovascular implants. Amphoteric polymers based on carboxylate betaine have become the research focus of surface modification of biomaterials in recent years. Its structure is similar to that of choline phosphate group, it has excellent biological antifouling property, and it has simpler synthesis method and stability. In addition, the carboxyl group on the surface of carboxylate betaine can be covalently bonded with the amino group of biomolecules. It provides an effective means to realize interface function design. Based on the amphoteric charge polymer of carboxylate betaine, a coating material with good biodegradability and blood compatibility was designed and constructed. The active short peptide REDV (Arg-Glu-Asp-Valan) with endothelial cell selection was immobilized on the surface of the coating. The nonspecific impedance of carboxylate betaine group and the specific induction of REDV short peptide were investigated to prepare the coating with selective endothelial cell function. The random copolymers of betaine methacrylate (CBMA) and butyl methacrylate (BMA) with different hydrophilic ratios were prepared by free radical copolymerization. The functional coatings, which can stably exist on the substrate surface, were successfully prepared by adjusting the polymerization monomer group. The carboxyl group on the surface of the coating was further activated by NHS/EDC and reacted with the amino group of the short peptide REDV. The basic physical and chemical properties of REDV functionalized carboxylate betaine copolymer coating were characterized. The coating still has obvious anti-protein adsorption ability, and excellent anticoagulant and anti-platelet adsorption ability. The growth behavior of human umbilical vein endothelial cells (HUVECs) and human umbilical artery smooth muscle cells (HUASMCs) on the surface of REDV functionalized carboxylate betaine copolymer coating was studied. The selectivity of endothelial cells on the surface of functionalized carboxylate betaine copolymers was achieved through the nonspecific impedance of carboxylate betaine components to smooth muscle cells and the specific induction of REDV short peptides to endothelial cells. The introduction of carboxylate betaine enhanced the ability of coating to select endothelial cells and inhibited the growth and migration of smooth muscle cells. In this work, a REDV functionalized carboxylate betaine copolymer coating with good bioantifouling ability, blood compatibility and endothelial cell selectivity was successfully constructed. It provides a basis for the further application of amphoteric betaine polymer in the surface modification of cardiovascular stent.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08

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