珍珠贝生物大分子螺旋膜自组装调控生物矿物成核及螺旋位错生长

In response to various environmental factors, a group of microstructures of the screw dislocation are assembled in multiphase screw dislocations on the surface of the nacreous layer of Pteria penguin from the coastal waters of Hainan Island, and Hyriopsis schlegeli from the fresh waters of Jiang Xi,China. In view of the organic matter periodically secreted by epithelial histology of mantle of pearl oysters pre-forms the original screw dislocation growth template in the form of film，along with its function to select, identify, and adhere to the amorphous calcium carbonate particles as the fine organic venations diffused in the epitaxial screw growth area. With the inducement and screw modulation of the organic film and venations, the amorphous calcium carbonate particles gradually evolve into the pseudohexagonal aragonite microsheet with long-range order and screw dislocation structure by location-selecting tropism and screw dislocation growth. Numerous micron-scale aragonite microsheets join in the cluster's interactive movement and screw dislocation self-assembly of the organic film，stacking forward along the axis C spirally and forming the nacreous layer with screw dislocation structur This research project by using the LA-ICP-MS , HRTEM，MICRO-XED，SEM，FT-IR，ESI-MS and the other testing instruments，intends to study the growth structure of the nacreous layer on Pteria penguin and Hyriopsis schlegeli from a microscopic viewpoint. It is found that a group of complex growth structure systems formed by the self-assembly of screw dislocation cluster will develop periodically in this kind of nacreous layer. More importantly, this paper discusses the screw dislocation nucleation of the amorphous calcium carbonate particles under the inducement of the organic film as well as the process of the location- selecting tropism and formation of the nacreous layer at the organic-inorganic interface of the nacreous layer on Pteria penguin. Additionally, we discuss the biomineralization mechanism of the screw dislocation on the nacreous layer, which is of great significance in the exploration of the biomineralization from the microstructure angle and the high-performance bionic materials, as well as in the design and preparation of the new type of organic-inorganic nanometer screw stratified composite materials.

基于各种环境因子的响应, 产自海南岛的海水企鹅珍珠贝和江西抚州淡水池蝶蚌珍珠层及培育的珍珠表层普遍发育螺旋位错生长结构。采用LA-ICP-MS、HRTEM、 MICRO-XED、SEM、FT-IR、 ESI-MS、拉曼光谱等分析测试方法，对发生在不同水域珍珠贝的有机～无机界面相处，生物大分子膜与无定形碳酸钙的界面识别，螺旋位错自组装调控，生物矿物相变，成核结晶与择位取向及螺旋位错生长等生物矿化问题进行研究。旨在探索生物大分子膜构筑初始螺旋位错生长模板及全程参与调控和螺旋位错自组装的生物矿化的形为，对揭示生物矿物在生物大分子膜螺旋位错自组装调控下的相变、成核结晶、择位取向及水环境因子的响应机理等生物矿化规律，筛选由珍珠层微生长结构中记录的各种生态环境信息，丰富生物矿化理论具有重要的意义。进而为高性能仿生工程材料和新型有机～无机纳米螺旋层状复合材料的设计与制备提供科学理论依据。

珍珠层与棱柱层是海水珠母贝和淡水珍珠蚌及珍珠中普遍发育一种独特生物矿化生长结构单元。利用自然生物矿化环境，以各类珠母贝和珍珠蚌及珍珠为研究载体，重复采用“平珠法”和“游离珠法”实时开展珍珠层和棱柱层体内生物矿化过程的实验研究。重复实验和综合测试结果一并表明，珍珠层和棱柱层生物矿化进程大抵经历过三个重要的生物事件，即活性细胞在初始界面上增殖与分化等生物化学行为，活性细胞与活性钙蛋白因子在界面生物流体中动态效应，生物矿物分形与螺旋多级自组装结晶生长行为；珍珠层和棱柱层界面生物化学效应实质是：由珠母贝和珍珠蚌外套膜上表皮分泌的活性细胞与活性钙蛋白因子，在界面生物流体中增殖、分化及物质交换与能量传递的生物矿化动态过程；通过界面活性钙蛋白因子的调节钙信号与诱导，从分子水平调控界面生物流体中活性细胞快速运移、黏附及自聚合，并沿珍珠层和棱柱层界面自发转化为纳、微米细胞团聚体和亚稳定无定形碳酸钙（ACC）团聚体；在非平衡、非线性快速结晶生长条件下，由ACC团聚体原位快速自相变的文石和球文石及方解石团粒，以其独特放射、枝晶及针梭晶团簇等分形自组装生长方式结晶生长，构成不规则多边形初始珍珠层生长基板；由文石微板片集群构成螺旋珍珠层具有严格{001}择优结晶取向，单个文石微板片螺旋露头为珍珠层螺旋自组装生长界面提供永驻台阶源。无数微米级文石微板片以螺旋露头为生长中心，沿c轴方向呈蜷线状逐层向前紧密堆垛生长，最终形成的珍珠层具高度有序螺旋自组装生长组构，其形貌、微生长结构呈现多样性；项目尚采用Matlab程序语言和R2014a成图软件等建模环境，就珠母贝珍珠层界面处生物矿物多级自组装生长过程进行计算机数值建模与分析，并获得珍珠层螺旋自组装生长与演化过程的数值模拟生长模式。研究成果对于深层次探索生物矿化机制，拓展并完善生物矿化理论具有重要科学意义，并为生态环境、生命科学、纳米新材料研发及珍珠养殖技术改善等方面提供科学依据。