| The often astonishing materials properties of crystalline biominerals are generally related to the hierarchical assembly of specifically interacting organic and inorganic components. A yet unfulfilled dream of many scientists is to synthesize new materials with similar advanced properties applying Nature?s biomimeralization strategies. An absolute prerequisite for the design of such hybrid materials with predetermined structure and properties is to unravel the mechanisms of biologically and biomimetically controlled mineral formation. To achieve this I will combine my expertise on designer polymer systems and advanced cryo-transmission electron microscopy (cryoTEM) to study biomimetic mineral formation. Although the approach is applicable to many different minerals, the program will concentrate on the biomedically and industrially important calcium phosphate and calcium carbonate. In bio(mimetic) mineral formation three hierarchical levels can be distinguished, associated with: 1) pre-nucleation clusters, 2) amorphous mineral phases and 3) the crystalline state. Within three projects the emergence of these subsequent stages and the pathways leading from one to another will be investigated: 1) The structure, composition and aggregation behavior of the recently discovered prenucleation clusters will be analyzed in detail. The generality of their role and their existence in materials other than calcium carbonate and calcium phosphate will be investigated. 2) We will investigate how charged (bio)polymers control the formation and development of amorphous precursor phases and how these polymers eventually become embedded within the crystal. The project will study the interaction between designer polymers and pre-nucleation clusters, the nature of which will determine the degree of inclusion of the polymer. 3) In Nature crystallization occurs in confined space and in a gel-like environment which both affect the amorphous-to-crystal transition. Internally structured block copolymer nanospheres will be used as soluble templates to study the details of these effects in solution. Our state-of-the-art cryoTEM facilities will be crucial in unraveling these details. |
