An international team of scientists has shown for the first time that living organisms are able to manufacture biominerals with organization of up to eight levels. The research focused on the skeleton of Mediterranean red coral. This coral, shown on the photography made by Joaquim Garrabou, has a crystalline order that is almost perfect at nanometric scale and could help in the development of new materials.
“This research into red coral shows for the first time that biominerals (minerals synthesised by living beings) display a crystalline order made up of up to eight hierarchical levels of modules”, explains Joaquim Garrabou, co-author of the study and a biologist at the CSIC Institute of Marine Sciences, “each module is made up of other smaller ones, and is in turn a component of other larger ones”.
The study, published in the journal American Mineralogist, was led by researchers from the Marseilles Interdisciplinary Nanoscience Centre (France), with collaboration from the California Institute of Technology (United States). The work focuses on red coral (corallium rubrum), an invertebrate that lives in the rocky depths of the Mediterranean and Western Atlantic.
Researchers at the Max Planck Institute of Colloids and Interfaces and collaborators at the University of California at Santa Barbara and the University of Chicago believe they have uncovered the basis how marine mussels use the byssus, a bundle of tough and extensible fibres, to fasten securely to wave-swept rocky coastlines.
(I) Mussels attach to hard surfaces in the marine intertidal zone with the byssus. (II) Byssal threads are extensible fibers with a hard and rough-textured protective cuticle (scanning electron microscopy). The knobby morphology of the cuticle originates from granular inclusions embedded in a continuous matrix. (III) The amount of dopa-iron complexes was found to be much higher in the granules than the matrix, which likely leads to their differences in mechanical performance during stretching. (Image: Matt Harrington, Max Planck Institute of Colloids and Interfaces)