Brushite: Synthesis, Properties, and Biomedical Applications
Khalil Issa, Abdulaziz A. Alanazi, Khalid A. Aldhafeeri, Ola Alamer, Mazen Alshaaer
Abstract
In this chapter, besides its biomedical applications, the synthesis and properties of brushite were investigated. Brushite consists of two types of crystals, platy and needle-like, and their formation depends on the pH of the medium during precipitation. Platy crystals are formed in a slightly acidic medium, pH = 5, and needle-like crystals at a higher pH = 6.5–7. In this study, the monoclinic brushite crystals were synthesized using dissolution-precipitation reactions. It is found that the brushite crystal growth occurs mainly along the (020) crystallographic plane. The thermogravimetric analysis confirms the presence of the two structural water molecules, which decompose at a temperature range between 80 and 220°C. Brushite was used in the preparation of tetracalcium phosphate mineral, which is the powder component for calcium phosphate cement (CPC). CPC was subsequently prepared from TTCP and phosphate-based hardening solution. In vitro evaluation of the resultant CPC using Hanks’ Balanced Salt Solution results in the growth of nanofibrous crystals of Calcium-deficient hydroxyapatite (CDHA) layers on the surfaces of the CPC. The cultured CPC exhibits new connective tissues and throughout the CaP matrix.