Octacalcium phosphate microscopic superstructure self-assembly and evolution by dual-mediating combination

Abstract

The morphologies of biomimetic mineralized octacalcium phosphate (OCP) are extremely versatile. Numerous studies have addressed the gel phases, surfactants, polyelectrolytes and thin layers as convenient media to produce OCP nanostructures with various morphologies. However, hardly any studies have to date discussed the concept of controlling the structural evolution of these nanostructures by organic molecule mediation. This paper aims at opening the pathway to such OCP assemblies with levels of morphological expression and evolution from an aqueous solution consisting of highly diluted acidic macromolecule and amphiphilic small molecule as co-mediators. This approach differs in that the usual organic molecules are used to shape the single OCP morphology, and specifically establish an evolutionary relationship between the lamellar clusters and spherical aggregates. We present a possible model that gives qualitative description for the morphology of OCP grown in a variety of molar ratios between acidic macromolecule and small molecule surfactant. We believe that extension of the present approach to other biominerals and inorganic materials will prepare a large variety of highly flexible biomimetic nanostructures with elaborate superstructures across nanoscale to macroscopic dimensions.