Curcumin and quercetin as templates in the in vitro biomineralization of CaCO3: A comparative study on phase modulation

Biomineralization of calcium-based biominerals is influenced by organic molecules containing oxygen donor atoms. In this work, we were able to synthesize and stabilize the least stable crystalline phase of CaCO3, vaterite, using the biologically useful organic molecule curcurnin as the template. The vaterite phase formed was stable in solution at least for 18 h. A comparative study with chemically similar molecule quercetin, a flavonoid, was performed. Though quercetin as a template could not stabilize the vaterite phase, an interesting observation was made in terms of the morphology of the calcite particles obtained. A dumbbell-shaped morphology, different from the usual rhombohedral morphology of the calcite crystals was obtained under ambient conditions. The maturation of the CaCO3 crystals in solution with time was studied to observe the changes in terms of phase and morphology of the particles. Additionally, extended studies were performed to investigate the influence of the change in parameters such as; template concentration, the sequence of addition, temperature and ionic strength on the phase, morphology and size of the particles in the presence of both the templates.

Automated summary

In this study, organic molecules were used as templates to synthesize and stabilize the least stable crystalline phase of CaCO3, vaterite. While curcumin successfully stabilized the vaterite phase, quercetin did not, leading to an interesting observation of dumbbell-shaped calcite crystals. Various parameters such as template concentration, sequence of addition, temperature, and ionic strength were investigated to understand the influence on the phase, morphology, and size of the particles during the biomineralization process.