Intergrowth and Interfacial Structure of Biomimetic Fluorapatite–Gelatin Nanocomposite: A Solid-State NMR Study

The model system fluorapatite–gelatin allows mimicking the formation conditions on a lower level of complexity compared to natural dental and bone tissues. Here, we report on solid-state NMR investigations to examine the structure of fluorapatite–gelatin nanocomposites on a molecular level with particular focus on organic–inorganic interactions. Using ³¹P, ¹⁹F, and ¹H MAS NMR and heteronuclear correlations, we found the nanocomposite to consist of crystalline apatite-like regions (fluorapatite and hydroxyfluorapatite) in close contact with a more dissolved (amorphous) layer containing first motifs of the apatite crystal structure as well as the organic component. A scheme of the intergrowth region in the fluorapatite–gelatin nanocomposite, where mineral domains interact with organic matrix, is presented