Preparation of Chinese mystery snail shells derived hydroxyapatite with different morphology using condensed phosphate sources

Chinese mystery snail is a popular aquatic food in China, resulting in tonnes of shells as waste every year. In present work, these shells were recycled as calcium source to prepare HA. Initially, shells were found to decompose within 860 °C to porous CaO. The calcined shells were then hydrothermally utilized to synthesize HA with the help of different phosphate sources (PO43−, P2O74−, P3O105−, and P6O186−). Under hydrothermal processing, condensed phosphate ions could be hydrolyzed into PO43− to react with Ca2+. The prepared HA was subsequently characterized by XRD, FTIR, SEM, EDX and TEM. It was found condensed phosphates could result in significant changes to the morphology of HA in comparison to orthophosphate. In particular, P6O186− related HA appeared to be mesoporous. The cytocompatibility of different phosphate source related HA was also investigated.