Discovery of New Phenomena in Biomineral Formation

生物矿物形成新现象的发现

• 批准号: 1603192
• 负责人: Pupa Gilbert
• 金额: $ 45万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1603192&HistoricalAwards=false
• 关键词: Discovery; New; Phenomena; Biomineral; Formation

Non-technical: This award by the Biomaterials program in the Division of Materials Research to University of Wisconsin Madison is to investigate the mechanisms for the formation of natural biominerals. These biominerals are crystalline composite materials formed by living organisms. Despite being crystalline, they do not frequently exhibit the flat faces and sharp edges characteristic of geologic crystals, but have rounded surfaces, and shapes highly adapted to their functions. They grow by attachment of amorphous particles, as was first discovered in sea urchin biominerals, and later in eggshells and others, but never directly in the formation of seashells. This proposal will analyze these biominerals to study how they are formed. Using crystal orientation measurements, this award will study crystal growth in egg shells in a quantitative manner. The discoveries coming out of this study will greatly advance knowledge of biomineral formation mechanisms, and the results will be helpful for future biomimetic 3D printing of these biominerals, with potential use in bone repair and replacement, and other useful devices. The discoveries in these biominerals will be broadly disseminated in peer-reviewed publications, at conferences where the researcher gives frequent invited lectures, in popular science magazines, at the Conference for Undergraduate Women in Physics, to under-represented minority high-school students attending the "Pre-college EnrichmentOpportunity Program for Learning Excellence" program, to grade school women attending the Expanding Your Horizon yearly events, and in public lectures.Technical: The researcher and the team members will study new phenomena in forming biominerals, selected to maximize the likelihood of new, unexpected results because they have never been studied with the same objectives as planned here: Objective 1 is to identify amorphous precursor phases in fresh, forming mussel nacre and prismatic layers, and eggshells using x-ray absorption near-edge structure spectroscopy at the calcium L-edge, and localization in component-mapping with 20 nm spatial resolution, and 3 nm probing depth. Calcite, aragonite, and their amorphous precursors have distinct XANES spectral lineshape and are therefore identifiable. If there are amorphous precursor phases in forming eggshell, nacre and prisms, we will identify them as proto-aragonite or proto-calcite. These "polyamorphs" have the short-range order of aragonite and calcite, respectively, and are expected to transform into the corresponding crystalline phases. Objective 2 is to obtain a quantitative definition of spherulite from synthetic aragonite using polarization-dependent imaging contrast (PIC)-mapping at the oxygen K-edge. This definition will then be used to determine if nacre and eggshells do or do not grow spherulitically. Both component- and PIC-mapping are state-of-the-art synchrotron methods, which this researcher introduced and continues to improve.

非技术性：威斯康星大学麦迪逊分校的生物材料计划颁发的奖项是调查形成自然生物工厂的机制。这些生物矿物是由活生物体形成的结晶复合材料。尽管是结晶的，但它们并不经常表现出地质晶体的平坦面部和锋利的边缘，而是圆形的表面和形状高度适应其功能。它们是通过在海胆生物矿物和蛋壳和其他人的后来发现的无定形颗粒的附着而生长的，但从未直接直接形成贝壳。该提案将分析这些生物矿物质，以研究它们的形成方式。使用晶体取向测量值，该奖项将以定量的方式研究蛋壳中的晶体生长。这项研究的发现将大大提高生物矿物形成机制的知识，结果将有助于将来的仿生3D打印这些生物矿物质，并有可能在骨修复和更换中使用，以及其他有用的设备。 The discoveries in these biominerals will be broadly disseminated in peer-reviewed publications, at conferences where the researcher gives frequent invited lectures, in popular science magazines, at the Conference for Undergraduate Women in Physics, to under-represented minority high-school students attending the "Pre-college EnrichmentOpportunity Program for Learning Excellence" program, to grade school women attending the Expanding Your Horizo​​n yearly技术：研究人员和团队成员将研究新现象的形成生物工具，以最大程度地提高新的，出乎意料的结果的可能性，因为它们从未与此处计划的相同目标进行研究：目标1是为了确定新鲜的，NACRESS的不形成式群体和蛋sbless的范围，并识别出不形成的前体阶段。在钙l-边缘，并在组件映射中定位，并具有20 nm空间分辨率和3 nm探测深度。方解石，后者及其无定形前体具有不同的XANES光谱线形，因此可识别。如果在形成蛋壳，nacre和棱镜中存在无定形前体阶段，我们将把它们识别为原始的阿拉贡石或原始钙岩。这些“多形”分别具有后期和方解石的短距离顺序，并有望转化为相应的晶体。目标2是使用依赖于极化的成像对比度（PIC）映射的氧气K-边缘的偏振化成像对比度（PIC）从合成后期获得的定量定义。然后，将使用此定义来确定Nacre和蛋壳是否在球形上生长。组件映射和PIC映射都是最先进的同步物方法，该研究人员介绍并继续改进。