CELL AND GENETIC APPROACHES TO ENAMEL BIOMIMETICS

牙釉质仿生学的细胞和遗传学方法

• 批准号: 6516537
• 负责人: Malcolm L. Snead
• 金额: $ 32.7万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6516537
• 关键词: bioengineering /biomedical engineering; biomaterial development /preparation; biomaterial evaluation; biomimetics; dental development; dentin; dentinogenesis; genetically modified animals; laboratory mouse; tissue engineering; tissue support frame; tooth enamel

Teeth are tissue composites in which each tissue produces a unique matrix whose protein component(s) direct biomineralization. The outer covering of teeth is a highly ordered, acellular bioceramic called enamel. Enamel is built upon dentin, similar but distinctive from bone. We predict that hierarchical gene expression for dental proteins results in a structural hierarchy. In this application we will acquire information about enamel structural hierarchy needed to produce an enamel biomimetic. The protein template directing the inorganic phase will be analyzed in vitro using recombinant produced an enamel proteins. The unique interface between enamel and dentin, the dentin enamel junction (DEJ), plays a critical role in the biomechanical function of the tooth. Presently there is a paucity of information about DEJ development, the proteins contributing to formation and the organization of these proteins yielding an interface between materials of such dissimilar biomechanical properties. To produce an enamel biomimetic requires the ability to recapitulate the DEJ. We will test the hypothesis that DEJ formation is dependent upon the expression of specific genes encoding structural proteins that undergo admixture at the interface and this mixture at the interface and this mixture is essential to bonding enamel to dentin. We will modulate the DEJ interface and the bulk enamel in transgenic animal using tissue specific promoters to express selected protein at the DEJ and within enamel. The complementary approach of targeted gene deletion will be used to ablate the contribution of selected structural proteins. Genetically stable lines of mice will be created whose teeth will reflect novel morphologic and structural features. A first generation enamel tissue replacement, complete with DEJ, will be produced using immortal ameloblast-like cells organized into a tissue-like three dimensional scaffold yielding an enamel biomimetic complete wit DEJ. Collaborative research with Dr. Baer and Dr. Sarikaya will identify biomechanical properties of teeth from control mice as well as from ~gain or loss of function~ mice. Four specific aims are proposed: 1) Determine the effect(s) of selected tooth specific proteins on mineral deposition and composition in vitro; 2) Using transgenic animals as part of a gain of function test, determine the effects of excessive amounts of selected tooth specific proteins on tooth biomineralization in vivo; 3) Alter the dentin enamel junction and/or bulk enamel using homologous recombination to reduce or eliminate a tooth specific protein in vivo as part of a loss of function test; 4) Produce artificial enamel by providing a three-dimensional framework for enamel biomineralization under the control of reconstituted enamel organ epithelia. These experiments, coupled to collaborative interactions with material scientist at University of Washington and Case Western Reserve University will enable a rational design for a human enamel biomimetic device.

牙齿是组织复合材料，每个组织都会产生独特的 其蛋白质成分直接生物矿化的基质。 这 牙齿的外覆盖是高度有序的细胞生物陶瓷 称为搪瓷。 搪瓷建在牙本上，相似但独特 从骨头。 我们预测牙齿的分层基因表达 蛋白质导致结构层次结构。 在此应用中，我们 将获取有关所需的搪瓷结构层次结构的信息 产生牙釉质仿生。 指导蛋白质模板 使用重组产生的重组者将在体外分析无机阶段 牙釉质蛋白。 搪瓷和牙本质之间的独特接口， 牙本质搪瓷结（DEJ）在 牙齿的生物力学功能。 目前有很少的 有关DEJ开发的信息，蛋白质有助于 这些蛋白质的形成和组织产生 这种不同的生物力学材料之间的接口 特性。 要产生搪瓷仿生剂，需要能够 概括DEJ。 我们将测试DEJ形成的假设 取决于编码特定基因的表达 结构性蛋白质在界面上发生混合，这 界面的混合物和该混合物对于粘结至关重要 搪瓷到牙本质。 我们将调制DEJ接口和批量 使用组织特异性启动子到转基因动物的搪瓷 在DEJ和牙釉质内表达选择的蛋白质。 这 靶向基因缺失的互补方法将用于 消除所选结构蛋白的贡献。 遗传 将创建稳定的小鼠线，其牙齿将反映出新颖 形态和结构特征。 第一代搪瓷 将使用DEJ替换的组织替换 不朽的成成木细胞形成了组织样的三个 尺寸脚手架产生牙釉质仿生完整的机智。 与Baer博士和Sarikaya博士的合作研究将确定 来自对照小鼠的牙齿的生物力学特性以及 〜功能〜小鼠的增益或丧失。 提出了四个具体目标：1） 确定选定牙齿特异性蛋白的效果 体外矿物沉积和成分； 2）使用转基因 动物作为功能测试的一部分，确定 牙齿上过多的选定牙齿特异性蛋白 体内生物矿化； 3）更改牙本质搪瓷结和/或 使用同源重组来减少或消除大量搪瓷 牙齿特异性蛋白在体内作为功能测试丧失的一部分； 4） 通过提供三维框架生产人造搪瓷 在重构的控制下，用于搪瓷生物矿化 搪瓷器官上皮。 这些实验与协作结合 与华盛顿大学的物质科学家的互动和 案例西部储备大学将为一个理性设计 人搪瓷仿生装置。