Osteoderms of Heloderma suspectum - A new nano-micro hierarchical biomineralized structure in vertebrates

作者：亚历山大Kirby 1合作者：Michael Jossi 1 Meiden Moazen 2，Susan Evans 3，Sergio Bertazzo 11伦敦大学学院医学物理与生物医学工程系，London WC 1 E 6 BT，UK 2伦敦大学学院机械工程系，托灵顿Place，London WC 1 E 7 JE，UK 3伦敦大学学院细胞与发育生物学系，Gower Street，London WC 1 E 6 BT，UK摘要：Helodermatidae是一个有毒蜥蜴家族，在皮肤内进化出了骨皮。自从他们第一次被报道以来，骨皮通常被描述为骨或骨样结构，这一概念从未受到彻底的挑战。在该项目中，评估了Helicobacter suspectum（Gila monster）骨胚层的纳米/微米特征，并与来自同一动物的骨骼和牙齿样品进行了比较。该表征研究将使用先进的物理化学分析进行，例如与聚焦离子束（FIB）相关的电子显微镜。在微观尺度上，扫描电子显微镜的结果将证明或反驳，吉拉怪物的骨皮可以分为三个区域：一个高度矿化的致密材料存在于骨皮的上部区域;一个骨样材料贯穿骨皮，显然围绕着脉管系统;和矿化区域，其中直径约10微米的胶原纤维组织成三维网。在纳米尺度上，通过FIB制备的样品的透射电子显微照片将证明或反驳这一假设，即三个不同区域中的每一个都是独特的，呈现出不同的纳米结构和不同的结晶度，如X射线衍射法所示。我们还假设，与取自同一动物的骨骼和牙齿样本的比较表明，骨胚层确实是一种独特的矿化组织，而不是简单的骨样组织。然后，这些结果可能证明一个迹象，在脊椎动物中，自然的非病理性硬组织比怀疑的更多样化，这表明存在着全新的细胞和生化生物矿化系统。进一步的初步结果表明，这里描述的三个结构的吉拉怪物是蜥蜴的骨皮的基本组成部分，在不同物种之间的形状和比例的变化，这三个结构。最后，除了在脊椎动物中发现的新硬组织的生物、进化和生态意义之外，本文描述的迄今为止未知的纳米/微米结构可能在未来的转化应用中被证明是有价值的，包括创造具有特殊性能的仿生和仿生材料。由于这些原因，本研究与EPSRC生物材料研究领域以及开发未来疗法、物理干预前沿和先进材料的战略/重大挑战保持一致。作者声明，本研究不需要伦理批准。

Author:Alexander Kirby1Collaborators:Michael Jossi1 Mehran Moazen2, Susan Evans3, Sergio Bertazzo11Department of Medical Physics & Biomedical Engineering, University College London, London WC1E 6BT, UK2Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK 3Department of Cell & Developmental Biology, University College London, Gower Street, London WC1E 6BT, UKSummary:Helodermatidae is a family of venomous lizards that has evolved osteoderms within the skin. Since they were first reported, osteoderms have generally been described as bone or bone-like structures, and this concept has never been thoroughly challenged. In this project, the nano/micro characteristics of the osteoderms of Heloderma suspectum (Gila monster) are evaluated and compared to bone and tooth samples from the same animal. This characterization study is to be done using advanced physical-chemical analyses, such as electron microscopy associated with focused ion beam (FIB). At the micro scale, scanning electron micrograph results will prove or disprove that the osteoderm of the Gila monster can be divided into three regions: a highly mineralised dense material present in the upper region of the osteoderm; a bone-like material that runs through the osteoderm, apparently surrounding vasculature; and a mineralised region, with collagen fibers of approximately 10 microns of diameter organized in a three-dimensional mesh. At the nano scale, transmission electron micrographs of samples prepared by FIB will prove or disprove the hypothesis that each of the three different regions is unique, presenting different nanostructures and different crystallinity, as demonstrated by x-ray diffractometry. We also hypothesise that comparison with samples of bone and teeth taken from the same animal reveal that the osteoderm is indeed a unique mineralised tissue and not a simple bone-like tissue. These results then may prove an indication that in vertebrates, natural non-pathological hard tissues are more diverse than suspected, suggesting the existence of completely novel cellular and biochemical biomineralization systems. Further preliminary results indicate that the three structures described here for the Gila monster are the fundamental components of osteoderms in lizards, with variations in the shape and proportion of these three structures between species. Finally, beyond the biological, evolutionary and ecological significance of a new hard tissue discovered in vertebrates, the hitherto unknown nano/micro structures described here may potentially prove valuable in future translational applications, including the creation of biomimetic and bioinspired materials with special properties. For these reasons, this study is well aligned to the EPSRC research area of biomaterials and the strategies/grand challenges of developing future therapies, frontiers of physical intervention and advanced materials.The authors declare that no ethical approval was required for this study.