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.

牙齿是组织复合体，其中每个组织产生唯一的 其蛋白质成分(S)直接生物矿化的基质。这个 牙齿外层覆盖物是一种高度有序的脱细胞生物陶瓷。 叫做珐琅。牙釉质是建立在牙本质上的，相似但不同 从骨头里。我们预测牙科的基因表达具有层次性 蛋白质导致了一个结构层次。在此应用程序中，我们 将获取有关牙釉质结构层次结构的信息 生产一种仿生牙釉质。该蛋白质模板指导着 无机相将在体外用重组产物进行分析 一种釉质蛋白质。牙釉质和牙本质之间的独特界面， 牙本质釉质结合部(DEJ)在牙周组织中起着关键作用。 牙齿的生物力学功能。目前有一个稀缺的 关于DEJ发育的信息，这些蛋白质有助于 这些蛋白质的形成和组织产生一个 生物力学性能如此不同的材料之间的界面 属性。生产牙釉质仿生体需要有能力 简而言之，《美国司法部》。我们将检验DEJ形成的假设 取决于编码特定基因的表达 在界面上发生混合的结构蛋白，这 界面上的混合物，这种混合物对粘合是必不可少的 牙釉质到牙本质。我们将调制DEJ界面和主体 利用组织特异性启动子在转基因动物中的牙釉质 在DEJ和牙釉质中表达选定的蛋白质。这个 将使用靶基因缺失的互补方法来 消融选定的结构蛋白的作用。从基因上讲 将创造出稳定的老鼠品系，它们的牙齿将反映出新的 形态和结构特征。第一代珐琅 组织替换，包括DEJ，将使用以下技术生产 永生的成釉细胞样细胞排列成组织样的三个 三维支架产生牙釉质仿生完整。 与贝尔博士和萨里卡亚博士的合作研究将确定 对照小鼠牙齿的生物力学特性 ~功能的获得或丧失~小鼠.提出了四个具体目标：1) 确定选定的牙齿特异蛋白对牙齿的影响(S) 体外矿物沉积和组成；2)利用转基因 动物作为获得功能测试的一部分，确定了 牙齿上所选的牙齿特异性蛋白含量过高 活体生物矿化；3)改变牙本质牙釉质交界处和/或 大量釉质使用同源重组减少或消除 作为丧失功能测试的一部分的体内牙齿特异性蛋白；4) 通过提供三维框架来生产人造牙釉质 在重组的控制下进行牙釉质生物矿化 釉质器官上皮。这些实验，再加上协作 与华盛顿大学材料科学家的互动和 凯斯西储大学将为 人牙釉质仿生装置。