Thermodynamic Aspects of Biomineralized Tissue Formation
Dr. Igor Zlotnikov, B CUBE – the Center for Molecular Bioengineering at the Technical University of Dresden, Germany
Living organisms form complex mineralized composites that perform a variety of essential functions, ranging from structural and mechanical support, to optical, magnetic or sensing capabilities. This remarkable diversity in functionality is accomplished from a relatively narrow range of constituent inorganic materials that form hierarchically structured mineral-organic architectures. The control over biomineral shape, at all hierarchical levels, is a key aspect of the structure-to-function relationship in these materials. Although many studies have emphasized the critical role of biochemical regulation during biogenic mineral formation, the physical constraints that govern the growth process of naturally occurring biocomposite assemblies and determine the form of the constituent biomineral building blocks are not yet understood. Here, the fundamental question of how nature takes advantage of thermodynamic principles to generate complex morphologies will be addressed. Using analogies to well-known principles from classical materials science, the basis for understanding the physical processes and the forces that control the morphogenesis of biomineralized tissues in time and in space will be provided. The formation of two types of tissues will be highlighted: the calcium carbonate shells of molluscs that exhibit a large diversity of unconventional mineral morphologies, and amorphous glass spicules from marine sponges that are a paradigm of symmetry in biological systems.