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

Abstract

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 inorgan-ic 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 genera-tion of materials with improved mechanical, chemical and physical properties. We thus attempt to follow nature‟s fabrication strategy of using biomolecules and study the min-eralization process in-situ which might shed light on the mechanistic aspects of control-ling 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 re-sults 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 struc-tural and mineralization mechanisms were compared with the biological samples. The comparative studies of the structural features will help to optimize the structure of mate-rials for improved mechanical properties.