Secondary Structure of DNA Aptamer Influences Biomimetic Mineralization of Calcium Carbonate

Calcium materials, such as calcium carbonate, are produced in natural and industrial settings that range from oceanic to biomedical. An array of biological and biomimetic template molecules have been employed in controlling and understanding the mineralization reaction but have largely focused on small molecule additives or disordered polyelectrolytes. DNA aptamers are synthetic and programmable biomolecules with polyelectrolyte characteristics but with predictable and controllable secondary structure akin to native extracellular moieties. This work demonstrates for the first time the influence of DNA aptamers with known Gquadruplex structures on calcium carbonate mineralization. Aptamers demonstrate kinetic inhibition of mineral formation, sequence and pH-dependent uptake into the mineral, and morphological control of the primarily calcite material in controlled solution conditions. In reactions initiated from the complex matrix of ocean water, DNA aptamers demonstrated enhancement of mineralization kinetics and resulting amorphous material. This work provides new biomimetic tools to employ in controlled mineralization and demonstrates the influence that template secondary structure can have in material formation.

Automated summary

This study demonstrates the influence of DNA aptamers with known G-quadruplex structures on calcium carbonate mineralization for the first time. Aptamers show kinetic inhibition of mineral formation, sequence and pH-dependent uptake into the mineral, and morphological control of calcite material in controlled solution conditions. In reactions initiated from ocean water, DNA aptamers enhance mineralization kinetics and result in amorphous material. This work provides new biomimetic tools for controlled mineralization and highlights the importance of template secondary structure in material formation.