Protein Science Laboratory of the Ministry of Education, School of Life Science, Tsinghua University, Beijing, 100084, China.
Protein Science Laboratory of the Ministry of Education, School of Life Science, Tsinghua University, Beijing, 100084, China; Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang Province, 314006, China.
Biochem Biophys Res Commun. 2021 Jul 23;563:47-53. doi: 10.1016/j.bbrc.2021.05.067. Epub 2021 May 28.
Biomimetic materials inspired by biominerals have substantial applications in various fields. The prismatic layer of bivalve molluscs has extraordinary flexibility compared to inorganic CaCO. Previous studies showed that in the early stage, minerals expanded horizontally and formed prism domains as a Voronoi division, while the evolution of the mature prisms were thermodynamically driven, which was similar to grain growth. However, it was unclear how the two processes were correlated during shell formation. In this study, we used scanning electronic microscopy and laser confocal scanning microscopy to look into the microstructure of the columnar prismatic layer in the pearl oyster Pinctada fucata. The Dirichlet centers of the growing domains in mature prisms were calculated, and the corresponding Voronoi division was reconstructed. It was found that the domain pattern did not fit the Voronoi division, indicating the driving forces of the mature prisms evolution and the initiation stage were different. During the transition from horizontal expansion to vertical growth, the minerals broke through the inner periostracum and squeezed out the organic materials to the inter-prism space. Re-arrangement of the organic framework pattern was driven by elastic relaxation at the vertices, indicating the transition process was thermodynamically driven. Our study provided insights into shell growth in bivalves and pave the way to synthesize three-dimensional material biomimetically.
受生物矿化启发的仿生材料在各个领域都有广泛的应用。与无机碳酸钙相比，双壳类软体动物的棱柱层具有非凡的柔韧性。先前的研究表明，在早期，矿物质横向扩展并形成棱柱域，作为 Voronoi 划分，而成熟棱柱的演化是由热力学驱动的，类似于晶粒生长。然而，在贝壳形成过程中，这两个过程是如何相关的还不清楚。在这项研究中，我们使用扫描电子显微镜和激光共聚焦扫描显微镜观察珍珠贝 Pinctada fucata 的柱状棱柱层的微观结构。计算了成熟棱柱中生长域的 Dirichlet 中心，并重建了相应的 Voronoi 划分。结果表明，域模式不符合 Voronoi 划分，这表明成熟棱柱演化和起始阶段的驱动力不同。在从水平扩展到垂直生长的过渡过程中，矿物质突破了内壳层并将有机材料挤出到棱柱间空间。在顶点处的弹性松弛的驱动下，有机框架模式的重新排列表明过渡过程是由热力学驱动的。我们的研究为双壳类动物的贝壳生长提供了新的认识，并为仿生合成三维材料铺平了道路。
