Biomimetic Synthesis of an Enamel-Like Material

描述（由申请人提供）：生物技术的最新进展使得牙釉质的细胞外基质的蛋白质和蛋白酶可用，并促进了它们的体外功能研究，以及允许首次尝试在人工环境中合成这种钙化组织。 本提案的总体目标是确定蛋白质引导的材料开发所需的物理化学条件，该材料与人类牙釉质的组成、结构和性质相当。 这项工作应导致更好地了解釉原蛋白，剪接变体LRAP+和两种蛋白酶在离子和分子水平上的生物矿化过程中的功能，以及如何使用这些信息在体外合成釉质。 要测试的假设是，当在特定的物理化学条件下在矿化溶液中与所选的蛋白酶组合时，通过使用全长和剪接的人釉原蛋白，可以仿生合成釉质样材料的薄层，包括组成、微观结构和性质。 这一假设将通过以下三个具体目标进行检验：（1）确定促进全长釉原蛋白和剪接变体LRAP+介导的生物矿化的物理化学条件;（2）确定釉原蛋白诱导的生物矿化是否依赖于磷灰石基质的晶体学取向;和（3）在矿化进行的同时，通过使用重组MMP-20和丝氨酸蛋白酶逐渐降解釉原蛋白基质来合成釉质样材料。

DESCRIPTION (provided by applicant): Recent advances in biotechnology made proteins and proteases of the extra cellular matrix of enamel available and facilitate the study of their function in-vitro as well as allowing the first attempts to synthesize this calcified tissue in an artificial environment. The overall objective of the current proposal is to determine the physical-chemical conditions required for a protein-guided development of a material that is comparable to the composition, structure and properties of human enamel. This work should lead to an improved understanding of how amelogenin proteins, the spliced variant LRAP+ and two proteases function in the biomineralization process on an ionic and molecular level and how this information can be used to synthesize enamel in-vitro. The hypothesis to be tested is that a biomimetic synthesis of thin layers of an enamel-like material, including composition, microstructure and properties is feasible by the use of full-length and spliced human amelogenins, when combined with selected proteases in mineralizing solutions at specific physical-chemical conditions. This hypothesis will be tested by the following three specific aims: (1) To determine the physical-chemical conditions that promote biomineralization mediated by full-length amelogenin and the spliced variant LRAP+; (2) To determine if amelogenin-induced biomineralization depends on the crystallographic orientation of the apatite substrate; and (3) To synthesize an enamel-like material by gradually degrading the amelogenin matrix using recombinant MMP-20 and serine proteinase while mineralization proceeds.