聚己内酯的表面改性及其对细胞行为的影响

发布时间：2018-04-02 11:32

本文选题：表面修饰　切入点：聚己内酯　出处：《华东理工大学》2012年硕士论文

【摘要】：材料的表面性质不仅能影响细胞的粘附和增殖,并且会影响细胞的分化,最终可控制组织的生成。聚己内酯(PCL)具有良好的生物相容性和生物降解性,以及优良的机械性能和可加工性,因此,受到了广泛关注。但是亲水性差,缺乏可反应性官能团和生物活性分子等表面性质,导致了材料与细胞间相互作用弱,使其在组织工程领域中的应用受到了限制。因此,聚己内酯的表面改性来提高其长期生物相容性己成为其在组织工程领域中应用的热点。本论文旨在通过对聚己内酯材料进行表面改性,包括对其进行氨基官能团修饰和引入特异性识别分子半乳糖,给细胞创造一个良好的人工ECM环境,模拟细胞外的基质环境,并进一步研究材料表面性质的改变对细胞的调控行为。本论文的主要工作内容如下： 1.通过控制单体投料比合成了一系列不同含量氨基修饰的聚己内酯材料(NPCL)。利用接触角测试仪、X—射线光电子能谱仪和原子力显微镜重点考察了材料的表面亲水性、表面元素组成和表面形貌。氨基的引入增加了材料的亲水性并使得材料表面粗糙度增加。采用人间充质干细胞(hMSC)为模型细胞来评估了NPCL支架材料的生物相容性,并研究了材料表面理化性能对细胞行为的影响。由于材料亲水性的提高、表面拓扑结构的改善以及NPCL材料表面正电荷和带负电干细胞之间存在静电作用,NPCL材料对hMSC细胞的粘附、增殖和分化起到促进作用,是非常具有潜力的新型组织工程支架材料。 2.以乳糖酸和NPCL聚合物为原料,在1-乙基-3(3-二甲氨丙基)碳二亚胺盐酸盐和N-羟基琥珀酰亚胺缩合剂的催化作用下合成了侧链带半乳糖的聚己内酯(GPCL)。核磁、红外光谱和凝胶渗透色谱法表征了聚合物的结构和分子量并确证了乳糖酸分子偶联成功,广角X射线衍射和差示扫描量热法表征了聚合物的结晶性和热力学性能。 3.将合成的新型半乳糖修饰的GPCL材料铺成膜,采用HepG2细胞株为模型细胞来评估半乳糖的引入对聚己内酯材料带来的影响。血球计数板计数法和肌动蛋白染色结合检测接种后细胞粘附效率,CCK-8试剂盒绘制HepG2细胞增殖曲线,扫描电镜以及Live-Dead荧光染色观察细胞形态和死活状况,白蛋白分泌量测试考察HepG2细胞在聚合物膜上肝功能表达状况。GPCL上的半乳糖分子与分布在HepG2细胞表面的去唾液蛋白酶之间的特异性识别作用提高了细胞与材料间相互作用,引导了细胞粘附并促进了细胞增殖及活性维持。
[Abstract]:The surface properties of the material not only affect cell adhesion and proliferation, but also affect cell differentiation, and ultimately control the formation of tissue. PCL has good biocompatibility and biodegradability. Because of its excellent mechanical properties and processability, it has attracted wide attention. However, due to its poor hydrophilicity and lack of surface properties such as reactive functional groups and bioactive molecules, the interaction between materials and cells is weak. Therefore, the surface modification of polycaprolactone to improve its long-term biocompatibility has become the focus of its application in tissue engineering. The purpose of this thesis is to create a good artificial ECM environment for cells by modifying the surface of polycaprolactone materials, including modification of amino functional groups and introduction of specific recognition molecule galactose, to simulate the extracellular matrix environment. Furthermore, the regulatory behavior of the surface properties of the materials on the cells was further studied. The main contents of this thesis are as follows:. 1. A series of polycaprolactone materials with different contents of amino modified polycaprolactone were synthesized by controlling the feed ratio of monomers. The surface hydrophilicity of the materials was investigated by means of contact angle tester, X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). The introduction of amino groups increased the hydrophilicity of the NPCL scaffolds and increased the surface roughness. The biocompatibility of NPCL scaffolds was evaluated by using human mesenchymal stem cells (hMSCs) as model cells. The effect of surface physical and chemical properties on cell behavior was studied. Due to the improvement of hydrophilicity, the improvement of surface topology and the existence of electrostatic interaction between positive charge and negatively charged stem cells on the surface of NPCL materials, the adhesion of NPCL materials to hMSC cells was studied. Proliferation and differentiation are potential new scaffolds for tissue engineering. 2. Polycaprolactone (GPCL) with galactose was synthesized from lactate and NPCL polymer under the catalysis of 1-ethyl-3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide condensation agent. The structure and molecular weight of the polymer were characterized by IR and gel permeation chromatography, and the molecular coupling of lactate was confirmed. The crystallization and thermodynamic properties of the polymer were characterized by wide-angle X-ray diffraction and differential scanning calorimetry. 3. The new galactose modified GPCL material was prepared. HepG2 cell line was used as model cell to evaluate the effect of galactose on the polycaprolactone material. The cell adhesion efficiency after inoculation was determined by blood cell counter counting and actin staining. The HepG2 cell proliferation curve was plotted by CCK-8 kit. Scanning electron microscopy (SEM) and Live-Dead fluorescence staining were used to observe the morphology and death of cells. The specific recognition of galactose molecules on HepG2 cells and sialytic proteases distributed on the surface of HepG2 cells enhanced the interaction between cells and materials. It leads cell adhesion and promotes cell proliferation and activity maintenance.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08

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