Bio-inspired Magnetite Mineralization in Gelatin Hydrogels : A Small Angle Scattering Investigation

Biomineralization represents a sophisticated process of forming a highly hierarchically ordered mineral structure by a living organism. The process is carried out under strict biological control of specially designed biomacromolecules. Mineralization mechanisms permitting such sophistication control typically involve interaction between an inorganic mineral and an organic matrix interface. A clear understanding of the mechanisms of this process may pave way for exploration of new material design strategies and generation of materials with improved mechanical, chemical and physical properties. We thus attempt to follow nature‟s fabrication strategy of using biomolecules and study the mineralization process in-situ which might shed light on the mechanistic aspects of controlling the process. The aim of this work is to investigate, understand and probably control the mechanism of bio-inspired magnetite mineralization in organic matrices and the organic-inorganic hybrid structures by Small Angle Neutron and X-ray Scattering methods. The studies focus on the nucleation and growth of the magnetite particles in the gelatin hydrogel matrix by employing biomineralization strategies from three natural bio-minerals. The SANS contrast matching method was used by the variation of heavy water content in the H2O/D2O mixture in order to emphasize the structure of the individual components of the complex material on the different stages of biomineralization process. These results have provided structural information and understanding of the mechanisms of magnetite mineralization as well as in-situ. Several hypotheses have been introduced to explain functionality of the organic matrix in magnetite biomineralization. These structural and mineralization mechanisms were compared with the biological samples. The comparative studies of the structural features will help to optimize the structure of materials for improved mechanical properties.