Addressing of different synthetic and shaping approaches for β-tri calcium phosphate macro-microporous scaffold fabrication

Abstract

The importance of facile and reliable route for preparing pure beta-tricalcium phosphate (β-TCP) is immense for bone grafting application. In addition to compositional purity, repercussions related with control over development of porosity, i.e. shaping, are even greater. In this study, we considered two facile synthesis paths from aqueous solutions of calcium nitrate and diammonium hydrogenphosphate for preparation of β-TCP based powder; (I) controlled approach; a slow calcium deficient hydroxyapatite (CDHA) precipitation method with controlled pH, and (II) fast approach; a rapid CDHA precipitation, followed by calcination to obtain the β-TCP based form. After synthesis, we experimentally optimised the parameters for the production of ceramic templates with various morphology and microstructure through: (I) 3D printing, and (II) foam replication templating. Regarding the synthesis, X-ray diffraction (XRD) confirmed that the slow precipitation method yields pure β-TCP after calcination, while for the fast method, β-TCP in mixture with minor β-CPP (beta-calcium pyrophosphate) quantities was obtained. For both approaches, hydroxyapatite (HA) was not observed even in traces. The prepared porous ceramic bodies were broadly characterized through their total porosity (Archimedes' method), microporosity and specific surface (adsorption-desorption isotherms) and morphology by scanning electron microscopy (SEM). Characterisations give rise to a reliable synthetic route for preparing of highly porous monophasic β-TCP bodies. The course of shaping and porosity development of β-TCP bodies was meticulously considered.