Inspired by the pioneering work of Prof. Rüdiger Kniep on fluorapatite‐gelatin nanocomposites also known as “Kniep's Dumbbells,” this study investigates carbonated fluorapatite‐gelatin aggregates synthesized by the double diffusion technique within a gelatin gel. The carbonate incorporation varies from 0.3 to 7.5 wt.% and occurs through B‐type substitution at phosphate sites. These materials closely resemble apatite‐based biological hard tissues and particularly enameloid of fish teeth. Electron microscopy reveals a complex composite structure of materials and morphogenesis pathway, progressing via branching process from elongated seed via dumbbell to spherulites. The morphogenesis is strongly affected by carbonate content by decreasing anisotropy of apatite crystal growth and pre‐impregnation of gelatin by calcium or phosphate ions. These findings provide valuable insight into biomineralization process of fluorapatite‐based biological hard tissues.
Sturm et al. (Mon,) studied this question.