Biogenic preparation of biphasic calcium phosphate powder from natural source of snail shells: bioactivity study

Abstract

Abstract In this present work, carbonated apatite powder (CAP) and β-tricalcium phosphate (β-TCP) were prepared from waste snail shells via thermal decomposition followed by chemical precipitation method with phosphoric acid in a one step process. The CAP produced was thereafter reacted with a pore forming agent solution of ammonium bicarbonate to formed carbonated apatite powder- ammonium bicarbonate scaffold composites (CAP-AMB) and was deployed in a bioactivity experiment with simulated body fluid (SBF) media. The phase purity, crystallinity, particle size, thermal behaviour, elemental composition, morphology as well as the functional groups of snail shells, synthesized CAP and CAP-AMB scaffold were assessed by XRD, FE-SEM, TGA, EDX, TEM and FT-IR. XRD and selected area electron diffraction (SAED) results confirmed the synthesized apatite as pure amorphous powder which upon heat treatment, transformed to polycrystalline powder. Analysis of FT-IR results revealed that the apatite produced from snail shells (SS) contains phosphates and hydroxyl functional groups. Furthermore, the formation of carbonated apatite was also confirmed from the FT-IR result with peaks which appeared at 882 and 1484 cm−1 respectively, thus depicting a B-type apatite. Microscopy analyses by FE-SEM and TEM indicated that the prepared apatite is composed of different morphologies in the range of 5 to 200 nm long. The presence of trace elements such as K, C, Na, Mg and Mg which could play crucial functions in biological applications were detected by EDX measurement alongside Ca and P. The mixture of CAP with AMB produced interconnected pores structure with porosity in the range of 35–67%. The bioactivity study of the SBF treated CAP-AMB composite confirmed apatite formation on the scaffold surface which totally covered the pores after seven days of incubation. Thus, waste biomaterial of snail shells origin can be use for the production of pure apatite that could be useful in medical application. Graphical abstract

Keywords

• Apatite
• Bioactivity
• Calcinations
• Carbonated powder
• Snail shells