胶原蛋白仿生材料的制备与性质研究

发布时间：2018-11-27 17:23

【摘要】：胶原蛋白是一类结构复杂、种类和功能多样的大家族。到目前为止,已经有28种不同类型的胶原蛋白被发现。其中有三种胶原蛋白(I型、II型、III型)含量最为丰富,占人体胶原蛋白含量的90%以上。它们具有完美的(Gly-X-Y)n重复序列模式和独特的三重螺旋结构,在人体内可以组装为高级纤维结构。胶原蛋白纤维形成一个分子支架,为人体提供结构完整性和机械强度。胶原蛋白作为细胞外基质的主要组成部分,由于其优越的生物学性能和结构特点,在再生医学和组织工程等领域广为应用。因此,研究胶原蛋白仿生材料,不仅会增进我们对胶原蛋白结构和功能的理解,而且为设计细胞外基质仿生材料等新型生物功能材料提供了新的思路。基于以上研究背景,本文主要围绕胶原蛋白新型仿生材料的设计、合成以及性质表征来展开研究,内容介绍如下:第一章:我们主要介绍了胶原蛋白的发展史、分类和结构,并概述了多肽自组装纳米材料的发展以及生物矿化。第二章:我们希望设计胶原多肽来模拟天然胶原蛋白的性质。我们首次构建了胶原多肽-镧系金属(Ln~(3+))体系,在Ln~(3+)的介导下,胶原多肽自组装形成有序的纳米绳结构,并很好地仿生了胶原蛋白特有的周期性条纹。Ln~(3+)作为光致发光材料,具有发光寿命长、毒性低、线性发射、光化学性质稳定性高等优点。Ln~(3+)不仅可以专一、可逆地调控多肽的自组装,并且赋予胶原多肽仿生材料独特的光学性能,在细胞成像、医学诊断和细胞培养的发光支架等领域具有良好的应用前景。第三章:我们以胶原蛋白为生物模板制备了形貌可控的Fe_2O_3纳米材料。与以前报道的蛋白质模板相比,我们的重组胶原蛋白不仅能够以较低的浓度更高效的调节赤铁矿晶体的分层组装结构,而且可以调控出形貌更丰富多样的纳米结构。胶原蛋白特异性的三重螺旋结构和氨基酸重复序列,可能赋予胶原蛋白作为生物模板的独特优势。研究表明,蛋白质不同的序列和结构特征可以调控新颖的纳米结构,对发展新型的蛋白-无机复合纳米材料具有重要意义。第四章:我们发展了一种生物矿化的方法,来制备蛋白酶-稀土离子的有机-无机复合纳米材料。在温和的生物矿化条件下,蛋白酶介导稀土离子形成球形纳米材料;与此同时,固定在高表面积的球形复合材料上的蛋白酶,表现出良好的活性。不仅比游离的蛋白酶更稳定,而且可以多次反复使用。研究表明,生物矿化为构建新型蛋白酶-无机复合材料提供了新的方法,在生物传感器、生物催化等领域具有重要意义。
[Abstract]:Collagen is a large family with complex structure, variety and function. So far, 28 different types of collagen have been found. Three kinds of collagen (type I, II, III) are the most abundant, accounting for more than 90% of human collagen. They have perfect (Gly-X-Y) n repeat pattern and unique triple helix structure, which can be assembled into advanced fiber structure in human body. Collagen fibers form a molecular scaffold that provides the human body with structural integrity and mechanical strength. Collagen, as the main component of extracellular matrix, has been widely used in regenerative medicine and tissue engineering due to its excellent biological properties and structural characteristics. Therefore, the study of collagen biomimetic materials will not only enhance our understanding of the structure and function of collagen, but also provide a new idea for the design of novel biological functional materials such as extracellular matrix biomimetic materials. Based on the above research background, this paper mainly focuses on the design, synthesis and characterization of collagen biomimetic materials. The main contents are as follows: chapter 1: we mainly introduce the history, classification and structure of collagen. The development and biomineralization of polypeptide self-assembled nanomaterials were also reviewed. Chapter 2: we want to design collagen peptides to simulate the nature of natural collagen. The collagen polypeptide lanthanide metal (Ln~ (3) system was constructed for the first time. Under the mediation of Ln~ (3), the collagen polypeptide self-assembled into an ordered nanowire structure. Ln~ (3), as a photoluminescence material, has the advantages of long luminescence life, low toxicity, linear emission, high photochemical stability and so on. Ln~ (3) is not only specific. It can control the self-assembly of polypeptide and endow with unique optical properties of collagen peptide biomimetic material. It has good application prospect in the fields of cell imaging, medical diagnosis and luminescent scaffold for cell culture and so on. Chapter 3: we prepared Fe_2O_3 nanomaterials with controllable morphology using collagen as a biological template. Compared with the previously reported protein templates, our recombinant collagen can not only regulate the layered assembly structure of hematite crystals at lower concentrations, but also regulate the morphology of the nanostructures. The specific triple helix structure and amino acid repeats of collagen may give collagen a unique advantage as a biological template. The results show that different sequences and structural characteristics of proteins can regulate novel nanostructures and play an important role in the development of new protein-inorganic composite nanomaterials. Chapter 4: we developed a biomineralization method to prepare organic-inorganic composite nanomaterials of protease-rare earth ions. Under mild biomineralization conditions, protease mediates rare earth ions to form spherical nanomaterials. At the same time, protease immobilized on high surface area spherical composites exhibits good activity. It is not only more stable than free protease, but also can be used repeatedly. The study shows that biomineralization provides a new method for the construction of new protease-inorganic composite materials, and has important significance in biosensor, biocatalysis and other fields.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R318.08

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