Hierarchical architecture and real structure in a biomimetic nano-composite of fluorapatite with gelatine: a model system for steps in dentino- and osteogenesis?

The morphogenesis of hierarchically ordered, spherical aggregates of fluorapatite–gelatine-nanocomposites starts with elongated hexagonal prismatic seeds, followed by fractal branchings and the development of growing dumbbell states. The general principles of this dramatic process of self-organisation are not yet known but should be laid out already in the real structure of the central seed (P. Simon, W. Carrillo-Cabrera, P. Formanek, C. Göbel, D. Geiger, R. Ramlau, H. Tlatlik, J. Buder and R. Kniep, J. Mater. Chem., 2004, 14, 2218, ). Here we describe the structure and inner architecture of the fluorapatite composite seeds which consist of self-similar nano-subunits nucleated by gelatine macromelecules. Although grown without any cell activities, the biomimetic composite closely resembles natural biomaterials based on interactions between collagen and apatite.