利用SET-LRP和点击化学对聚合物膜表面修饰和多肽功能化及其生物医用研究

发布时间：2018-03-12 06:53

本文选题：抗血栓　切入点：抗菌表面　出处：《天津大学》2014年博士论文　论文类型：学位论文

【摘要】：合成聚阳离子是一类理想的抗菌材料，因为它们类似于天然抗菌肽，但是此类材料的血液相容性依然面着临挑战。在本论文中，利用2-（叔丁基-氨乙基）甲基丙烯酸酯（TBAEMA）合成了均聚物；以及采用单电子转移自由基聚合反应（SET-LRP），利用聚乙二醇甲基丙烯酸酯（PEGMA，Mn=360Da）制备出聚乙二醇化的无规和嵌段共聚物。然后，利用碘代甲烷和溴己烷将前体聚合物中的仲胺基进行季铵化，得到了3个系列的季铵化聚合物。采用大肠杆菌方法对这些季铵化聚合物抗菌性能进行了评价，结果表明，最小抑菌浓度MICs，32-200mg/L；无规共聚与两嵌段共聚物相比，前者具有较高的MICs值。另外，还将这些阳离子聚合物接枝到聚碳酸酯聚氨酯（PCU）膜表面，发现改性膜表现出良好的抗大肠杆菌效果。此外，利用人血红细胞对这些这些材料的溶血性能进行了研究，结果发现，除季铵化的均聚物表现出最高的溶血性能之外，其他的两亲性聚阳离子只表现出很低的溶血反应。因此，本文设计的材料具有结构和功能可控性和价格低廉的优点，在生物医药和可植入材料领域具有应用价值。此外，通过硫醇-烯点击化学和交联反应，制备了PCU和两性离子聚降冰片烯为基础的弹性交联膜，用它作为细胞生长支架材料。首先，通过光引发硫醇-烯点击反应，通过半胱氨酸和聚降冰片烯的双键反应，将聚降冰片烯胺化；之后，以六亚甲基二异氰酸酯作为交联剂，控制其与PCU溶液反应。与空白膜相比，改性膜的拉伸强度（14-20MPa）和初始模量（8-14MPa）与空白膜的拉伸强度（12±4MPa）和初始模量（3±1）相比，得到大大提高。除了最高两性离子聚合物含量为28%膜，其断裂伸长率为b470±80%之外，包括空白膜在内的所有膜都表现出较高断裂伸长率（b740-900%）。5周的PBS降解实验表明，与空白PCU膜相比，改性材料的生物降解性能大大提高。采用上述反应条件，也可以利用L-半胱氨酸和β-巯基乙醇作为硫醇试剂，对PCU空白膜进行改性。利用MTT实验对改性材料细胞相容性进行了表征，采用EA.hy926细胞作为生长和增殖模型，1天、3天和7天的增殖结果表明，这些材料具有很好的生物相容性。本工作的主要特色是合成路线方便和材料独特。另外，在PCU弹性膜表面进行特定修饰，以便促进快速内皮化，同时抑制平滑肌和血小板吸附。首先，PCU表面接枝亲水性刷状聚合物，通过SET-LRP反应接枝PEGMA，随后再次通过SET-LRP反应，接枝甲基丙烯酸五氟苯酯(PFMA)活性单体，形成嵌段和接枝结构。烯丙胺与PPFMA经光引发聚合后改性，利用光引发硫醇-烯点击化学反应，得到短肽序列Cys-Ala-Gly，（CAG）功能化膜。对改性膜进行XPS和水接触角测定表征，CAG固定化浓度有效地提高到10-19pm/cm2。与全血接触时，不同功能化表面能够抑制血小板吸附。改性材料对内皮细胞和平滑肌细胞的粘附实验，考察了1,3和7天，，结果表明采用方法简便易行，改性表面具有锚定内皮细胞的靶向配体，所构建膜能够促进快速内皮化，具有作为组织工程应用的前景。
[Abstract]:Synthesis of cationic polymer is a kind of ideal antibacterial material, because they are similar to natural antimicrobial peptides, but such biocompatibility is still facing challenges. In this paper, using 2- (tert butyl - aminoethyl) methyl acrylate (TBAEMA) homopolymer was synthesized by single electron transfer; and free radical polymerization (SET-LRP), using polyethylene glycol methacrylate (PEGMA, Mn=360Da) were prepared by random PEGylation and block copolymers. Then, using methyl iodide and bromohexane precursor polymer in secondary amine quaternary ammonium, the quaternary ammonium polymer 3 series.
Using Escherichia coli methods for these quaternized polymer antibacterial properties were evaluated. The results show that the minimum inhibitory concentration of MICs, 32-200mg/L; random copolymer compared with two block copolymer, the former has higher MICs value. In addition, these will also be grafted cationic polymer to polycarbonate polyurethane (PCU) membrane surface, it is found that the modified membrane show a good effect against Escherichia coli. In addition, the hemolytic properties of human red blood cells of these materials were studied, the results showed that the homopolymer quaternization showed the highest hemolytic performance, the other two amphiphilic polycation showed only the hemolytic reaction is very low. So in this paper, the design of material structure and function has the advantages of controllability and low price, has application value in the biomedical and implantable materials.
In addition, through thiol ene click chemistry and the crosslinking reaction of PCU and preparation of amphoteric polymer reduced elastic crosslinked membrane norbornene based, use it as a scaffold material. First, by photoinitiated thiol ene click reaction, double bond reaction by cysteine and polynorbornene, will drop bornylene after amination; with six methylene diisocyanate as crosslinking agent, the reaction with PCU solution. Compared with the blank membrane, the tensile strength of the modified membrane (14-20MPa) and initial modulus (8-14MPa) tensile strength and blank membrane (12 + 4MPa) and initial modulus (3 + 1) compared greatly improve. In addition to the highest content of 28% zwitterionic polymer film, its elongation is B470 + 80%, all films including blank membrane, showed higher elongation (b740-900%) showed that PBS degradation of.5 weeks, compared with the blank PCU membrane, modified wood Biodegradable material is greatly improved. By using the above reaction conditions, can also use the L- cysteine and beta mercaptoethanol as thiol reagents, the blank of PCU membrane was modified. The modified material biocompatibility was investigated by the MTT experiment, using EA.hy926 as the cell growth and proliferation model, 1 days, 3 days and the 7 day the proliferation results show that these materials have good biocompatibility. The main feature of this work is the synthesis route is convenient and material is unique.
In addition, specific modifications in PCU elastic membrane surface, in order to promote rapid endothelialization and inhibit smooth muscle and platelet adsorption. Firstly, PCU grafted hydrophilic polymer brush, by the reaction of SET-LRP grafted PEGMA, then through SET-LRP reaction, Grafting Methacrylic acid ester (PFMA) activity of five fluorine monomer, forming block and the graft structure. Allylamine and PPFMA by photopolymerization after modification by photoinitiated thiol ene click reaction, get the sequence of peptide Cys-Ala-Gly (CAG) functional membrane. The modified membrane was XPS and water contact angle measurement, the immobilized CAG concentration effectively increased to 10-19pm/cm2. and whole blood contact when the different functional surface can inhibit platelet adhesion experiments. The adsorption of endothelial cells and smooth muscle cells of the modified materials, the effects of 1,3 and 7 days, the results show that the method is simple, the modified surface with anchor The target ligands of endothelial cells, which can promote rapid endothelialization, have a promising future for tissue engineering applications.

【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R318.08;O631.3

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