多功能等离子体聚合涂层构建及生物相容性研究
发布时间：2018-09-13 11:49
【摘要】：心血管疾病是引起人类死亡的重要病因。相比于药物治疗和外科手术治疗,介入治疗由于具有创伤小、即刻效果显著、长期效果相对较好等优点,是目前临床上治疗心血管疾病常用方法。血管支架是心血管疾病介入治疗的重要器械。在过去的几十年里,研究者们采用了多种技术来提高血管支架的疗效,特别是药物洗脱支架的临床应用,大大减低了支架内再狭窄的发生率。但是,目前支架内晚期血栓和再狭窄仍然是限制心血管支架在临床应用的两大并发症,要设计出符合临床要求的理想血管支架,仍需要不断探索。在血管支架材料等心血管植入材料表面固定特定生物学功能的生物分子,以提高材料表面的抗凝和促内皮修复功能是一个热点研究方向。但金属材料表面缺乏足够密度的官能团,从而制约了生物分子的表面固定量。等离子体聚合技术可以在多种材料(如玻璃、金属材料、高分子材料)和复杂几何形状工件的表面形成涂层,等离子体聚合涂层致密、柔韧性好,与基底之间的结合力好,能够抵御大的变形,更为重要的是,还可以依据后续需求,通过单体选择和工艺参数控制,获得不同浓度和不同种类的官能团的等离子体聚合涂层。因此,将其用于在植入过程中会发生很大形变的血管支架材料的表面改性,具有较为显著的优势。因此,本论文首先以烯丙胺(Aam)为单体,利用脉冲等离子体聚合技术,在缺乏反应性官能团的医用316L不锈钢表面制备了富含胺基官能团的等离子体聚烯丙胺(PPAam)涂层。然后将具有抗氧化、清除自由基、抗炎等作用的单宁酸(TA)分子固定在PPAam涂层表面,构建富含酚羟基的TA-PPAam功能涂层。通过接触角、红外光谱、X射线光电子能谱、酚羟基定量、胺基定量、石英晶体微天平等方法表征涂层的化学组成和TA的接枝量。通过体外血小板粘附实验和血管内皮细胞、血管平滑肌细胞、巨噬细胞种植实验,评价改性前后材料的血液相容性和细胞相容性,结果表明TA被成功固定在PPAam涂层表面,固定量约为330±12ng/cm2,该涂层具有较好的血液相容性、内皮细胞相容性和抗炎性。对于血管支架材料等心血管植入材料而言,表面具有抗凝血和促内皮修复等功能是非常重要的。本论文在温和条件下,在富酚羟基官能团的TA-PPAam功能涂层表面分别固定特异性直接凝血酶抑制剂比伐卢定(BVLD)和具有特异性促进血管内皮细胞生长的内皮细胞生长因子(VEGF ),分别构建BVLD@TA-PPAam和VEGF@TA-PPAam功能涂层。实验结果表明,BVLD和VEGF均成功固定在TA-PPAam涂层表面,其固定量分别为930 ± 80 ng/cm2和158±13 ng/cm2; BVLD和VEGF功能化的TA-PPAam涂层较好地保持了 BVLD和VEGF的生物学活性。其中VEGF@TA-PPAam表现出显著的促进血管内皮细胞的粘附和铺展增殖能力;BVLD@TA-PPAam通过特异性捕获凝血酶并抑制其活性,有效地抑制了血小板的粘附和激活,此外,该涂层还具有显著地促进内皮细胞粘附和生长的能力。这为多功能血管支架等心血管植入物的设计和构建提供了可能,为降低血管支架内再狭窄和晚期血栓等并发症的发生提供了可能。仅从某一个或某几个方面对血管内膜层进行模拟不一定能够获得理想的近似细胞或细胞外基质的功能。对血管支架材料等心血管植入材料表面进行多种生物分子修饰以赋予其表面多重生物学功能,能更好的模拟细胞或细胞外基质的功能,从而能获得多功能心血管植入物满足临床的需求。而要在血管支架材料等心血管植入材料表面获得多重功能,固定单一的生物分子一般很难达到要求。本文利用等离子体聚合技术,以Aam和丙烯酸(Aac)为聚合前驱体/单体,在316LSS支架材料表面成功构建了同时具有胺基和羧基双官能团的等离子体Aam/Aac共聚涂层。通过接触角、红外光谱、X射线光电子能谱、胺基定量、羧基定量等方法表征涂层的化学组成。通过血小板粘附实验,溶血实验,血管内皮细胞和平滑肌细胞种植实验以及动物皮下植入实验评价改性前后材料的血液相容性、细胞相容性和组织相容性。结果表明通过在316LSS表面沉积的Aam/Aac共聚涂层,在其表面成功引入了胺基和羧基,实现了惰性金属材料表面双重官能团化的目的,为后续双重分子接枝提供了反应位点。并在此基础上进一步进行了肝素(Hep)和BVLD的固定,其固定量分别为210± 6ng/cm2和195±8ng/cm2;采用两步法实现了 Hep和BVLD在富含胺基和羧基的Aam/Aac共聚涂层表面的共固定,Hep和BVLD的固定量分别为210 ng/cm2和200 ng/cm2,与单独的固定量相当,证明了分别利用Aam/Aac (1.5:1.5)共聚涂层表面的胺基和羧基能实现双分子的共固定,为构建多功能表面提供了良好的平台。综上,本文基于等离子聚合涂层构建具有多重功能的表面,并对改性前后的表面进行相关功能评价,以期更好的认识多种改性层在体外的生物相容性。为拓展等离子聚合涂层在生物材料表面改性领域的应用提供技术支撑,为多功能血管支架的设计和构建提供了新思路。
[Abstract]:Cardiovascular disease is an important cause of death in humans. Compared with drug therapy and surgical treatment, interventional therapy has the advantages of less trauma, remarkable immediate effect and relatively good long-term effect. It is a commonly used method in clinical treatment of cardiovascular diseases. Over the past few decades, researchers have used a variety of techniques to improve the efficacy of stents, especially the clinical use of drug-eluting stents, greatly reducing the incidence of in-stent restenosis. It is a hot research direction to immobilize biomolecules with specific biological functions on the surface of cardiovascular implants such as vascular stents to improve the anticoagulant and endothelial repair functions of the materials. Plasma polymerization can form coatings on the surfaces of various materials (such as glass, metal materials, polymer materials) and workpieces with complex geometry. Plasma polymerization coatings are dense, flexible, have good adhesion with the substrate, and can withstand large deformation. More importantly, plasma polymerization can also be used to resist large deformation. According to the following requirements, plasma polymerized coatings with different concentrations and different types of functional groups were obtained by selecting monomers and controlling process parameters. Therefore, it has obvious advantages to use them to modify the surface of vascular stent materials which will undergo great deformation during implantation. Therefore, allylamine (Aam) is the first monomer in this paper. A plasma polyallylamine (PPAam) coating was prepared on medical 316L stainless steel by pulsed plasma polymerization. Tannic acid (TA) molecules with antioxidant, free radical scavenging and anti-inflammatory properties were immobilized on the surface of the coating to construct a TA-rich phenolic hydroxyl group. PPAam functional coatings. Chemical composition and TA grafting amount of the coatings were characterized by contact angle, infrared spectroscopy, X-ray photoelectron spectroscopy, phenolic hydroxyl content, amino content and quartz crystal microbalance. Platelet adhesion test in vitro and vascular endothelial cells, vascular smooth muscle cells, macrophage implantation test were performed to evaluate the modified materials before and after modification. The results showed that TA was successfully immobilized on the surface of PPAam coating with a fixed amount of about 330 65 In this paper, BVLD and vascular endothelial growth factor (VEGF) were immobilized on the TA-PPAam functional coatings with phenolic hydroxyl groups under mild conditions to construct BVLD @TA-PPAam and VEGF @TA-PPAam functional coatings respectively. The results showed that both BVLD and VEGF were successfully immobilized on the surface of TA-PPAam coatings with fixed amounts of 930 80 ng/cm 2 and 158 BVLD@TA-PPAam effectively inhibits platelet adhesion and activation by specifically capturing thrombin and inhibiting its activity. In addition, BVLD@TA-PPAam also significantly promotes endothelial cell adhesion and growth. Complications such as stenosis and advanced thrombosis may occur. Simulating the intima of a vessel from one or more aspects does not necessarily lead to an ideal approximation of cellular or extracellular matrix function. Surface modification of cardiovascular implants such as vascular stents with a variety of biomolecules is performed to give them multiple regeneration. Biological function can better simulate the function of cell or extracellular matrix, so multi-functional cardiovascular implants can be obtained to meet the clinical needs. However, in order to obtain multiple functions on the surface of cardiovascular implants such as vascular stents, it is difficult to fix a single biological molecule. A plasma Aam/Aac copolymer coating with both amino and carboxyl groups was successfully constructed on 316LSS scaffolds. The chemical composition of the coating was characterized by contact angle, infrared spectroscopy, X-ray photoelectron spectroscopy, amino quantification and carboxyl quantification. Hemolysis test, vascular endothelial cell and smooth muscle cell implantation test and animal subcutaneous implantation test were used to evaluate the blood compatibility, cell compatibility and histocompatibility of the modified materials. Hep and BVLD were immobilized on the surface of Aam/Aac copolymer coatings with a fixed amount of 210 65 The fixed amount of Hep and BVLD is 210 ng/cm 2 and 200 ng/cm 2 respectively, which is equivalent to the fixed amount of Aam/Aac (1.5:1.5) copolymer coating. It is proved that the amino group and carboxyl group on the surface of Aam/Aac (1.5:1.5) copolymer coating can achieve bimolecular copolymerization, which provides a good platform for building multifunctional surface. Functional surfaces were evaluated before and after modification in order to better understand the biocompatibility of various modified layers in vitro, and provide technical support for expanding the application of plasma polymeric coatings in the field of surface modification of biomaterials, and provide new ideas for the design and construction of multi-functional vascular stents.
【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R318.08
本文编号：2241087
[Abstract]:Cardiovascular disease is an important cause of death in humans. Compared with drug therapy and surgical treatment, interventional therapy has the advantages of less trauma, remarkable immediate effect and relatively good long-term effect. It is a commonly used method in clinical treatment of cardiovascular diseases. Over the past few decades, researchers have used a variety of techniques to improve the efficacy of stents, especially the clinical use of drug-eluting stents, greatly reducing the incidence of in-stent restenosis. It is a hot research direction to immobilize biomolecules with specific biological functions on the surface of cardiovascular implants such as vascular stents to improve the anticoagulant and endothelial repair functions of the materials. Plasma polymerization can form coatings on the surfaces of various materials (such as glass, metal materials, polymer materials) and workpieces with complex geometry. Plasma polymerization coatings are dense, flexible, have good adhesion with the substrate, and can withstand large deformation. More importantly, plasma polymerization can also be used to resist large deformation. According to the following requirements, plasma polymerized coatings with different concentrations and different types of functional groups were obtained by selecting monomers and controlling process parameters. Therefore, it has obvious advantages to use them to modify the surface of vascular stent materials which will undergo great deformation during implantation. Therefore, allylamine (Aam) is the first monomer in this paper. A plasma polyallylamine (PPAam) coating was prepared on medical 316L stainless steel by pulsed plasma polymerization. Tannic acid (TA) molecules with antioxidant, free radical scavenging and anti-inflammatory properties were immobilized on the surface of the coating to construct a TA-rich phenolic hydroxyl group. PPAam functional coatings. Chemical composition and TA grafting amount of the coatings were characterized by contact angle, infrared spectroscopy, X-ray photoelectron spectroscopy, phenolic hydroxyl content, amino content and quartz crystal microbalance. Platelet adhesion test in vitro and vascular endothelial cells, vascular smooth muscle cells, macrophage implantation test were performed to evaluate the modified materials before and after modification. The results showed that TA was successfully immobilized on the surface of PPAam coating with a fixed amount of about 330 65 In this paper, BVLD and vascular endothelial growth factor (VEGF) were immobilized on the TA-PPAam functional coatings with phenolic hydroxyl groups under mild conditions to construct BVLD @TA-PPAam and VEGF @TA-PPAam functional coatings respectively. The results showed that both BVLD and VEGF were successfully immobilized on the surface of TA-PPAam coatings with fixed amounts of 930 80 ng/cm 2 and 158 BVLD@TA-PPAam effectively inhibits platelet adhesion and activation by specifically capturing thrombin and inhibiting its activity. In addition, BVLD@TA-PPAam also significantly promotes endothelial cell adhesion and growth. Complications such as stenosis and advanced thrombosis may occur. Simulating the intima of a vessel from one or more aspects does not necessarily lead to an ideal approximation of cellular or extracellular matrix function. Surface modification of cardiovascular implants such as vascular stents with a variety of biomolecules is performed to give them multiple regeneration. Biological function can better simulate the function of cell or extracellular matrix, so multi-functional cardiovascular implants can be obtained to meet the clinical needs. However, in order to obtain multiple functions on the surface of cardiovascular implants such as vascular stents, it is difficult to fix a single biological molecule. A plasma Aam/Aac copolymer coating with both amino and carboxyl groups was successfully constructed on 316LSS scaffolds. The chemical composition of the coating was characterized by contact angle, infrared spectroscopy, X-ray photoelectron spectroscopy, amino quantification and carboxyl quantification. Hemolysis test, vascular endothelial cell and smooth muscle cell implantation test and animal subcutaneous implantation test were used to evaluate the blood compatibility, cell compatibility and histocompatibility of the modified materials. Hep and BVLD were immobilized on the surface of Aam/Aac copolymer coatings with a fixed amount of 210 65 The fixed amount of Hep and BVLD is 210 ng/cm 2 and 200 ng/cm 2 respectively, which is equivalent to the fixed amount of Aam/Aac (1.5:1.5) copolymer coating. It is proved that the amino group and carboxyl group on the surface of Aam/Aac (1.5:1.5) copolymer coating can achieve bimolecular copolymerization, which provides a good platform for building multifunctional surface. Functional surfaces were evaluated before and after modification in order to better understand the biocompatibility of various modified layers in vitro, and provide technical support for expanding the application of plasma polymeric coatings in the field of surface modification of biomaterials, and provide new ideas for the design and construction of multi-functional vascular stents.
【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R318.08
【参考文献】
相关期刊论文 前5条
1 聂方园;马晓丰;;单宁酸的生物活性研究进展[J];化学与生物工程;2015年01期
2 张茵;袁晋青;;生物及金属可降解支架在冠状动脉粥样硬化性心脏病介入治疗中的研究进展[J];心血管病学进展;2013年01期
3 王玮;王敏;;经皮冠状动脉手术抗血栓治疗策略[J];循证医学;2009年06期
4 马志红,陆忠兵,石碧;单宁酸的化学性质及应用[J];天然产物研究与开发;2003年01期
5 秦为熹,齐治家;血小板生理功能的调节[J];生理科学;1982年05期
，本文编号：2241087
本文链接：https://www.wllwen.com/yixuelunwen/swyx/2241087.html
