Dresden 2009 – wissenschaftliches Programm
CPP 16.2: Poster
Dienstag, 24. März 2009, 14:00–16:30, P3
Allocation of crystalline and amorphous minerals in calcified tissues: A confocal Raman study — •Sabine Hild1,2, Helge Fabritius2, Torsten Fischer2, and Dierk Raabe2 — 1Institut für Polymerwissenschaften, JKU Linz, Linz, Austria — 2Max-Planck-Institut fuer Eisenforschung, Duesseldorf
The mineralized exoskeleton formed by the cuticle of crustaceans is an excellent model to study biological nano-composite materials. In spite of the diversity of crustacean species they share a similar structural principle for their cuticle: An organic matrix composed of chitin-protein fibers associated with variable amounts of biominerals. The most widespread mineral is crystalline and amorphous calcium carbonate and to lower amounts calcium phosphate. In contrast to calcium carbonate, only little is known about the modification, the distribution and the function of the latter. Using the combination of electron microscopy, Energy-Dispersive X-Ray Analysis, Raman spectroscopy and atomic force microscopy we studied the mineral distribution within the claw cuticle of the american lobster Homarus americanus. Similar to other crustaceans, in the lobster cuticle crystalline calcium carbonate is restricted to the exocuticle forming a continuous calcite layer only close to the surface. Further inside the crystalline phase forms a post-like structure. Amorphous calcium carbonate (ACC) is localized in between the crystalline domains and appears homogenously distributed within the endocuticle. It is accompanied by amorphous calcium carbonate (ACP). Selective dissolution and SFM nano-indentation experiments will provide further information about the function of ACC and ACP.