Effect of different synthesis conditions on physicochemical and biological properties of apatites

Abstract

Nanocrystalline, ionically modified hydroxyapatites mimicking bone apatite were synthesized. The powders obtained by the wet method were enriched with the main “foreign ions” naturally occurring in bone tissue: carbonates, sodium and magnesium ions. Various parameters of the wet method synthesis were modified: pH, the concentration of reagents, the temperature during the precipitation, and ageing time. The materials were subjected to physicochemical analysis with the use of various analytical methods, such as powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectroscopy (ICP-OES) and Fourier transform infrared spectroscopy (FT-IR). All the obtained materials were also biologically tested in vitro for their potential cytotoxicity and biocompatibility. The morphology, crystallite sizes and crystallinity indices were investigated and the content of hydrogen phosphates, carbonates, magnesium and sodium were analysed. The concentration of reagents and temperature affect the size and shape of crystallites, while pH and ageing time affect the amount of doped ions and the biocompatibility of materials. Optimal conditions for the synthesis of highly biomimetic and biocompatible materials have been identified.