牙釉质发育、成熟过程中晶体“水合层”的演变及作用机制研究

Enamel defect is one of the most common diseases in the clinic. Currently, investigation of the exact mechanism by which organic matrix mediates nano-hydroxyapatite (nano-HAP) is a very important research direction in the field of stomatology. “Hydrated layer” is the special “non-apatitic environment” on the surface of nano-HAP, which plays important role in the deposition of inorganic ions, adsorption of organic molecules and crystal fusion. We hypothesized that organic matrix accurately mediates the behavior of nano-HAP by virtue of “hydrated layer”. However, there was no systematic investigation about the development and the function of “hydrated layer” during the enamel amelogenesis until now. The present project starts to analyze the in vitro synthetic nano-HAP. Then recombinant amelogenin will be added for the following in vitro analysis. Lastly, the incisor enamel crystals of mice in vivo will be acquired at different maturation stages and then analyzed. To elucidate the structure and composition of the “hydrated layer” during the enamel development, Fourier Transform Infrared, Raman and solid nuclear magnetic resonance spectrum will be used to monitor the alterations of peculiar domains within “hydrated layer” in real time. Further, the morphology, crystallinity and maturity of crystals and the information of organics will be complementarily investigated. It is hoped that the current project will provide the detail mechanism of amelogenesis. More importantly, the current project is hoped to inspire the biomimetic mineralization for repairing the enamel defect.

牙釉质缺损是口腔临床上最常见的牙体疾患之一。目前，深入探索有机基质模板对无机晶体的精细调控是牙釉质缺损仿生修复的重要研究方向。“水合层”是纳米羟基磷灰石（Nano-HAP）表面一种可动态变化的特殊结构，与Nano-HAP晶体的无机离子沉积、有机物响应、晶体间融合组装等行为密切相关。我们推测有机基质通过“水和层”精密调控无机晶体行为，但目前尚无“水合层”在整个牙釉质发育、成熟过程的演变机制及作用研究。本项目从体外单一Nano-HAP的结晶、成熟过程着手，再引入基因重组釉原蛋白对Nano-HAP进行调控，并最终构建小鼠切牙在不同发育、成熟期的体内釉质模型。借助光谱学手段对上述体内、外模型进行实时监测，阐明牙釉质发育过程中“水合层”结构、成分的演变过程，再辅以其它多种先进技术手段进行同期相应有机基质和无机晶体的信息补充，力图深入理解牙釉质发育机制，为牙釉质缺损仿生修复提供新的关键思路。

牙釉质缺损是口腔临床上最常见的牙体疾患之一。深入探索有机基质模板对无机晶体的精细调控是牙釉质缺损仿生修复的重要研究方向。“水合层”是纳米羟基磷灰石（Nano-HAP）晶体表面一种可动态变化的特殊结构，与Nano-HAP晶体的无机离子沉积、有机物响应、晶体间融合组装等行为密切相关。.本项目从体外单一Nano-HAP晶体的结晶、成熟过程着手，再引入不同氨基酸等有机物对Nano-HAP进行调控，同时对牙釉质和本质中HAP晶体在不同微环境中的变化进行研究。这些结果阐明了晶体发育过程中不同时期成熟度、结晶度的变化以及“水合层”结构、成分等信息,为深入理解牙釉质发育机制及牙釉质缺损仿生修复提供新的思路。