Collaborative Research: Ontogeny, Mechanics and Function of the Tessellated Skeleton of Cartilaginous Fishes

合作研究：软骨鱼棋盘状骨骼的个体发育、力学和功能

• 批准号: 1027058
• 负责人: Adam Summers
• 金额: --
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1027058&HistoricalAwards=false
• 关键词: Collaborative; Research; Ontogeny; Mechanics; Function

This research project is a multi-level, interdisciplinary investigation of the structure and function of the mineralized portion of the cartilaginous skeleton. Cartilage is usually perceived as an articular material, a bearing surface between bony elements, or as contour-filler in the nose and ears. However, sharks and their relatives use cartilage as their skeletal material. This form of cartilage is lightly mineralized, with a surface coating of small, discrete blocks that completely cover the surface. Two factors make this 'tessellated' form of cartilage particularly interesting: 1) sharks abandoned a bony skeleton in favor of this cartilage so we may see the developmental and biochemical traces of early bone formation in the mineralization processes; and 2) since sharks, like human, cannot heal their cartilage it must be particularly resistant to fatigue damage over the life of the animal. Understanding the basis for this fatigue resistance may uncover a new class of biological materials that are both stiff and able to dissipate energy well. Preliminary data shows many differences between the mineralization process in tessellated cartilage and bone. The calcifying cells of tessellated cartilage do not enlarge and die as they do in bone, nor are the cells organized into files, but just as in bone there is a distinct region of organized collagen fibers on the edges of the mineralizing front. This may signal similarities at the developmental level. The researchers will investigate the extent of these similarities with histological techniques that probe for distinctive biochemical signals of developing bone. They will also use cryogenic scanning electron microscopy to examine the shape and arrangement of the cells in the developing mineralizing tissue. This microscopic and developmental investigation will be complemented by a study of the mechanics of the tessellated skeleton. Whole skeletal elements will be tested with a Periometer capable of measuring damping in living tissue to test the hypothesis that this tissue is very good at dissipating strain energy. These studies will be augmented with model-based investigations of the effect of mineralized block size and unmineralized cartilage stiffness on the damping qualities. A rapid prototyper will be used to 'print out' models with different block sizes and shapes, which will then be examined on a conventional material testing system. These experiments will be carried out by a collaboration between labs at the University of California - Irvine, George Washington University, the Max Planck Institute in Stuttgart, Germany and the Institute for Interdisciplinary Marine Sciences in La Paz, Mexico. The scientists, including graduate and undergraduate students, performing the research include developmental biologists, biomechanists, mechanical engineers and surface biologists. Several members of the group are under-represented minorities including one of the principal investigators and four of the graduate students.

该研究项目是对软骨骨骼矿化部分的结构和功能的多层次、跨学科研究。软骨通常被视为一种关节材料、骨元件之间的支撑表面，或鼻子和耳朵中的轮廓填充物。然而，鲨鱼及其近亲使用软骨作为骨骼材料。这种形式的软骨是轻度矿化的，具有完全覆盖表面的小而离散块的表面涂层。有两个因素使这种“棋盘格”形式的软骨特别有趣：1）鲨鱼放弃了骨骨骼，转而使用这种软骨，因此我们可以在矿化过程中看到早期骨形成的发育和生化痕迹； 2）由于鲨鱼和人类一样，无法治愈软骨，因此在动物的一生中必须特别能抵抗疲劳损伤。 了解这种抗疲劳性的基础可能会发现一类新型生物材料，这种材料既坚硬又能够很好地耗散能量。初步数据显示，棋盘状软骨和骨骼的矿化过程存在许多差异。棋盘状软骨的钙化细胞不会像骨骼中那样扩大和死亡，细胞也不会组织成文件，但就像骨骼一样，在矿化前沿的边缘有一个明显的有序胶原纤维区域。 这可能标志着发育水平上的相似性。研究人员将利用组织学技术来研究这些相似性的程度，这些技术可探测骨骼发育的独特生化信号。 他们还将使用低温扫描电子显微镜来检查发育中的矿化组织中细胞的形状和排列。这种微观和发育研究将通过对棋盘格骨架的力学研究进行补充。整个骨骼元件将使用能够测量活体组织阻尼的周长计进行测试，以检验该组织非常擅长耗散应变能的假设。 这些研究将通过基于模型的矿化块尺寸和未矿化软骨刚度对阻尼质量影响的研究得到加强。快速原型机将用于“打印”具有不同块尺寸和形状的模型，然后在传统材料测试系统上进行检查。 这些实验将由加州大学欧文分校、乔治华盛顿大学、德国斯图加特马克斯普朗克研究所和墨西哥拉巴斯跨学科海洋科学研究所的实验室合作进行。 进行这项研究的科学家，包括研究生和本科生，包括发育生物学家、生物力学学家、机械工程师和表面生物学家。该小组的几名成员是代表性不足的少数族裔，包括一名主要研究人员和四名研究生。