鱼胶原的体外自组装机制及其对胶原胶生物学性能的指针作用

The collagen fibril assembly is an important molecule behavior characteristic, which was used in the properties improvement and the application range broad for nature collagen. At present, the research about self-assembly mechanism of fish collagen has not been carried out in-depth. In this study, the self-assembly mechanism in vitro of fish collagen and its effect on the biological properties of collagen gel will be roundly discussed. The research results would be helpful for the application of fish collagen in the biomedical materials. The kinetics of self-assembly in vitro of fish collagen will be studied by the methods of fluorescent probe and viscoelastic modulus analysis to clarify the regular pattern of self-assembly behavior in different conditions and the behavior differences between fish and mammal collagens. In order to illustrate the molecular mechanism of self-assembly in vitro for fish collagen, the structure activity relationship between collagen structure and self-assembly behavior would be explored by use of some advanced technologies, such as mathematical model, electron microscope, nuclear magnetic resonance (NMR) and X-ray-diffraction (XRD) studies. The dependence relationship among self-assembly condition, product structure and cell biology response behavior would be analysed by the methods of self-assembly condition control and determination of biology properties of collagen gel. It was expected that some new ideals or theories could obtained from this work, which could be used in the new collagen biomaterials design.

自组装是胶原的重要分子行为特征，也是改善胶原性能，拓展其应用范围的有效手段。目前针对鱼源胶原蛋白体外自组装行为的相关研究尚未系统开展。该项目旨在通过鱼胶原体外自组装行为机制及其对胶原胶生物学性能影响机制的研究，为鱼源胶原蛋白在生物医学材料领域的应用和材料性能优化提供理论基础。采用荧光探针分析与粘弹模量分析相结合的方法研究胶原体外自组装动力学机制，阐明不同条件下鱼胶原的自组装行为规律、产物构造及其与哺乳动物胶原的异同；运用构建数学模型、电镜观察、NMR和X射线衍射测定等技术手段直观分析胶原结构与其体外自组装行为之间的构效关联，从多个层面理清鱼胶原蛋白体外自组装行为的分子机制；采用自组装调控、胶原胶构造分析和生物学性能测定的方法系统解析自组装条件、产物构造与细胞生物学响应行为三者之间的内在依存关系，为体外自组装技术在新型生物材料设计和材料性能优化中的应用提供新思路和理论依据。

本项目聚焦鱼源天然胶原，这一新兴的、潜在的医用生物材料，针对其特征性的分子行为—体外自组装，重点开展鱼源胶原体外自组装的动力学特征与分子学机制研究。在此基础上，进一步解析胶原自组装行为对组装胶原凝胶产物理化、生物学性能的影响；更进一步，研究环境因子、外环境干预等调控模式对胶原组装行为和产物性能的调控作用及其内在规律。通过项目研究，一是建立了浊度、荧光和流变学三种不同的自组装分析手段，全方位构筑了鱼源胶原体外自组装的动力学行为特征，明确了组装体系温度、pH、离子强度、离子种类、胶原浓度等因素对胶原组装动力学行为的影响以及对胶原组装纤维产物分子构造、凝胶性能的影响及其规律；二是从胶原分子端肽完整性、三螺旋构造完整性（热变性程度）、胶原氨基酸组成与分布三个层面阐释了胶原结构与胶原组装行为和组装产物性能特征（热稳定性能）之间的内在关联，建立氨基酸分布与胶原组装产物（胶原纤维）热解离行为之间的数学模型，明确了胶原分子间互作用的关键性作用方式和核心驱动力；三是运用流变学方法开展了组装条件与组装产物凝胶流变性能之间的内在关联性分析和研究，并进一步阐释了胶原凝胶质构与细胞生物学之间的耦合关联。四是建立了超声波、轴向离心力介入的两种胶原自组装行为调控模式，明确了不同力场环境下胶原自组装分子行为特征、组装产物结构和性能的演变规律。项目研究工作将对鱼源胶原在医学生物材料应用和新材料设计具有指导价值。一是可以通过自组装分子行为的科学运用，改进鱼源胶原的热稳定性和耐酶解稳定性，提高鱼源胶原的应用范围；二是可以通过改变组装体系环境因子，实现对组装胶原凝胶质构和粘弹性能的调控，满足不同领域对凝胶性能的差异化需求；三是通过介入外力场环境，可以构筑具有更优孔隙构造或更强抗拉性能的胶原材料，用于人造皮肤、跟腱等医学组织工程产品的设计和制造。