Calcium carbonate bio - precipitation in gelling environments via counter - diffusion

Zusammenfassung

O ver the last 3500 Myr or so, fi rst prokaryotes and then eukaryotes developed the ability to form minerals. From that time, organisms from many diff erent phyla evolved the ability to form the almost 70 diff erent biogenic minerals known to date.1 Biominerals are composite materials made of a mineral and an organic component, the so-called organic matrix. Th e most common minerals are calcium phosphate and calcium carbonate salts. Th ey give structural support to, for example, endoskeletons in mammals and birds and exoskeletons or shells of many diff erent organisms. Other examples include silica or elements rarely presented in organisms, such as iron and gold. Th e organic component of biominerals is composed of proteins, polysaccharides, glycoproteins, lipids, etc. In general, biominerals are used for many diff erent purposes depending on its nature, i.e. protection, mechanical strength, cutting, ions storage, optical, gravity or magnetic receptor. Biomineralization refers to the process by which organisms form biominerals. Th e formation of these hybrid organic-inorganic composites is a highly regulated process at diff erent levels, from the nanoscopic to the macroscopic scale, and leads to complex and unusual morphologies endowed of physical properties in many cases unparalleled yet by their synthetic counterparts. Th is huge control over mineral nucleation, growth and organization of the mineral crystals, leading in most cases to hierarchical structures, is a source of inspiration for materials scientists and fi nd applications in other disciplines as, for example, Biomedicine or Palaeontology. Interest in understanding and elucidating the mechanisms of biomineralization is not new but because of its potential applications in diff erent fi elds, it has grown tremendously in the last years.