DEJ--BIOMIMETIC MODEL FOR MATERIAL TISSUE INTERFACES

DEJ--材料组织界面仿生模型

• 批准号: 2649490
• 负责人: SALLY J MARSHALL
• 金额: $ 28.31万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 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/2649490
• 关键词: animal tissue; atomic force microscopy; biomaterial development /preparation; biomaterial interface interaction; dental bonding material; dental development; dental materials; dental stress analysis; dental structure; dentin; genetically modified animals; human tissue; laboratory mouse; tomography; tooth enamel

This project will quantify the structure-property relations at the dentin-enamel junction (DEJ) that are critical to tooth function and to determine if it embodies a fundamental design principle that can mimicked to produce fracture resistant interfaces of wide applicability. In addition it will also continue development of high resolution non- invasive imaging and measurement of nanolevel constituent properties that are critical to further understanding of calcified tissues. The DEJ unites two dissimilar calcified tissues. It plays a critical role in the biomechanical integrity of the tooth, is probably optimized for this function, and could serve as a biomimetic model for joining mechanically dissimilar biomaterials. Critical applications that could benefit from improved interfaces include orthopaedic and dental implants, as well as nearly all restorative dental procedures that relay on bonding or cementation. the central hypothesis is that the DEJ can be used as a biomimetic model for construction of new synthetic- biological substrate structures. Aim 1 will determine if the nanomechanical properties of the DEJ form a biomechanical interphase with graded mechanical properties across mammalian species (mouse, bovine, human) that leads to interfaces of enhanced fracture toughness. Novel methods of atomic force microscopy (AFM)-based nanoindentation allow measurement of modulus and nanohardness values. Fracture toughness will be determined using advanced methods that will validate new nanoscale fracture toughness methods for the DEJ. The structure- property relationships in transgenic mouse models with biomineralization defects of enamel or dentin will also be determined. Aim 2 will evaluate a 3-level (scallops, microscallops and nanostructure) DEJ model. X-ray tomographic microscopy, SEM and AFM will be used to define the architecture of the DEJ in human, bovine, mouse, and transgenic mouse teeth with mineralization defects. In Aim 3 current enamel bonding processes will be examined in light of the prior aims. The clinical success of enamel bonding procedures might stem from successful mimicry of the DEJ architecture as a byproduct of normal acid etching of enamel. The DEJ architecture may serve as an efficient means to bone and transmit forces between polymers and enamel, even in the absence of biological binding processes. Modifications that are more DEJ-like should improve bonding and fracture toughness. Aim 4 applies the most fracture resistant DEJ like architecture from the prior aims to a totally synthetic model to bond Si wafers to resin. The wafers will be patterned using lithography to determine the effects of each factor (microstructure, nanostructure, chemical bonding) on fracture toughness of the interface.

该项目将量化在 对牙齿功能至关重要的牙本质 - 内胺交界处（DEJ） 确定它是否体现了一个基本设计原则 模仿以产生较宽适用性的抗断裂界面。 此外，它还将继续发展高分辨率非 - 纳米级成分特性的侵入性成像和测量 这对于进一步了解钙化组织至关重要。 这 dej统一了两个不同的钙化组织。 它起着至关重要的作用 在牙齿的生物力学完整性中，可能已优化 此功能，可以作为加入的仿生模型 机械不同的生物材料。 可能的关键应用程序 改进的界面受益于骨科和牙科 植入物，以及几乎所有继电器的修复牙科程序 关于粘结或胶结。 中心假设是DEJ可以 用作构建新合成的仿生模型 生物底物结构。 AIM 1将确定是否 DEJ的纳米力学特性形成了生物力学之间 具有跨哺乳动物物种的机械特性（小鼠， 牛，人），导致骨折韧性增强的接口。 基于原子力显微镜（AFM）的新方法 允许测量模量和纳米性值。 断裂 将使用将验证的高级方法确定韧性 DEJ的新纳米级断裂韧性方法。 结构 - 具有生物矿化的转基因小鼠模型中的性质关系 也将确定搪瓷或牙本质的缺陷。 AIM 2意志 评估3级（扇贝，显微镜和纳米结构）DEJ 模型。 X射线断层扫描显微镜，SEM和AFM将用于定义 DEJ在人，牛，老鼠和转基因中的结构 矿物质缺陷的小鼠牙齿。 在AIM 3当前搪瓷 将根据先前的目的对粘结过程进行检查。 这 搪瓷粘结程序的临床成功可能源于成功 DEJ结构的模仿作为正常酸蚀刻的副产品 搪瓷。 DEJ架构可以作为骨骼的有效手段 并在聚合物和搪瓷之间传递力，即使在没有的情况下 生物结合过程。更类似于DEJ的修改 应该改善粘结和断裂韧性。 AIM 4最适合 从先前的目的到一个 完全合成的模型将si晶片粘合到树脂上。 晶片将 使用光刻来确定每个因素的影响 （微观结构，纳米结构，化学键合）骨折韧性 界面。