Collaborative Research: Bone as an interpenetrating composite material

非技术摘要：这个由材料研究部的生物材料计划授予伊利诺伊大学Urbana-Champion大学和加州大学圣地亚哥分校的合作项目是为了研究一种新的骨材料模型，即骨中的两个相蛋白质和矿物是相互渗透的(连续的)，并探索这一假说对骨骼的力学性能(包括强度和抗折性)有什么影响。骨骼由胶原蛋白和其他蛋白质、纳米矿物和水组成，所有这些都是分级自组装的。由于其复杂的等级结构，骨骼具有优异的性能；它坚固、僵硬、坚韧、重量轻。然而，导致这些优良特性的因素仍然没有被很好地理解。这项基础性和跨学科的研究将包括最先进的实验和多尺度建模，并将重点放在猪发育中的骨骼(0-48个月)，它的结构和成分随着年龄的增长而发生显著变化。这项研究的结果将导致对人类骨质量的更好预测，这仍然是一个突出的临床问题，并将指导设计具有优异力学性能的新型合成复合材料，应用于生物医学、交通运输和能源领域。来自不同背景的学生将参与这项前沿研究。将开发新的课程，并向技术和非专业观众提供短期课程和其他演示。技术摘要：骨是一种由胶原和其他蛋白质、羟基磷灰石矿物和水组成的生物纳米复合材料，它们都是分级组装的。这种复杂的结构使骨骼具有优越的特性(坚固、僵硬、坚韧和重量轻)。然而，造成这一现象的因素仍未得到很好的理解。在这个合作项目中，研究人员将检验两个假设：1)骨是由互穿的有机相和矿物相组成的复合材料；2)与分散增强相的复合材料相比，具有互穿相的合成生物灵感复合材料将具有更好的机械性能。更具体地说，这些研究人员将通过多尺度实验和建模来确定互穿模型是否适用于不同矿化程度和不同微观结构的骨骼。开发猪骨(0-48个月龄)将作为该项目的一部分进行研究，它展示了一系列的微观结构和矿物质含量。使用高能X射线在小角度和广角衍射，将胶原蛋白/矿物质水平上的应变作为施加应力的函数，与理论上获得的应变进行比较。此外，还将设计和测试具有互穿相的合成生物灵感材料，并将其性能与分散增强的复合材料的性能进行比较。该项目有望提供对骨骼层次结构的基本了解，从而更好地预测骨骼质量，并将指导针对不同应用的新型生物灵感合成复合材料的设计。来自不同背景的学生预计将参与这项尖端研究，包括第五章拉美裔高中的学生。将开发新的课程，并向技术和非专业观众进行演讲。

Non-Technical Abstract: This collaborative project award by the Biomaterials program in the Division of Materials Research to University of Illinois Urbana-Champion and University of California San Diego is to investigate a new model of bone as a material that the two phases in bone, proteins and minerals, are interpenetrating (continuous), and to explore what implications this hypothesis has on bone's mechanical properties, including strength and resistance to fracture. Bone is made of collagen and other proteins, nano-sized minerals and water, all hierarchically self-assembled. Bone has excellent properties due to its complex hierarchical structure; it is strong, stiff, tough and light weight. However, factors contributing to these superior properties are still not well understood. This fundamental and interdisciplinary study will include state-of-the art experiments and multiscale modeling, and will focus on porcine developing bone (0-48 months) which exhibits significant changes in its structure and composition with age. Results from this research will lead to better predictions of bone quality in humans, which is still an outstanding clinical issue, and will guide in the design of novel synthetic composite materials with superior mechanical properties for applications in biomedical, transportation and energy fields. Students from diverse backgrounds will participate in this cutting-edge research. New courses will be developed and short courses and other presentations will be given to technical and lay audiences. Technical Abstract: Bone is a biological nanocomposite material made of collagen and other proteins, hydroxyapatite minerals and water, all hierarchically assembled. This complex structure gives bone its superior properties (strong, stiff, tough and light weight). However, the contributing factors are still not well understood. In this collaborative project, researchers will test two hypotheses: 1) bone is a composite material made of interpenetrating organic and mineral phases; and 2) synthetic bioinspired composites with interpenetrating phases will have superior mechanical properties, compared to composites with a dispersed reinforcing phase. More specifically, these investigators will determine if the interpenetrating model is valid for bone with varying degrees of mineralization and different microstructures via multiscale experiments and modeling. Developing porcine bone (0-48 months old), which exhibits a range of microstructures and mineral contents will be studied as part of this project. Strains at the collagen/mineral level as a function of applied stress, using high energy x-rays diffracting at small- and wide-angles, will be compared with those obtained theoretically. In addition, synthetic bioinspired materials with interpenetrating phases will be designed and tested, and compared their properties to those of composites with a dispersed reinforcement. This project is expected to provide fundamental understanding of bone's hierarchical structure, which will lead to better predictions of bone quality and will guide the design of new bioinspired synthetic composites for different applications. Students from diverse backgrounds are expected to participate in this cutting-edge research, including the students from Title V Hispanic-serving high schools. New courses will be developed, and presentations will be given to technical and lay audiences.