(55h) Mimicking Complex Morphologies of Calcium Biominerals

Biominerals found in living organisms have diverse biological functions and distinct properties arising from the particular structure, orientation, and morphology of the constituent minerals. The morphological evolution of biominerals grown in organic matrices, and the interaction of such matrices with the inorganic crystals are important for understanding biomineralization processes and for developing bioinspired materials. In this work, we employ hydrogels as model organic matrices and a ‘double-diffusion’ method to mimic the formation of calcium oxalate, the major constituent of kidney stones. Gel-mediated crystallization provides a great way to vary the local supersaturation through controlling the diffusion rate of the reacting ions. We study the nucleation, growth, type of polymorph, orientation and aggregation of the calcium oxalate particles as affected by the gel density, reservoir concentrations, and molar stock solution ratio. We also explore the inhibitory effects of anionic macromolecules or small organic molecules on the biomineral formation. These findings help our understanding of the mechanism of polymer incorporation in biomineral aggregates, and provide insights into the formation of organic-inorganic composite materials. Furthermore, they guide the design and synthesis of therapeutic agents (modifiers with molecular recognition for crystal faces) to control biomineralization-associated diseases.