Chemical synthesis and stabilization of magnesium substituted brushite

Hydroxyapatite (Ca-10(PO4)6(OH)(2)) is the most ubiquitous calcium phosphate phase used in implant coatings and more recently in gene/drug delivery applications due to its chemical stability under normal physiological conditions (37 degrees C, pH similar to 7.5, 1 atm.). However, different calcium phosphate phases, such as brushite (CaH (PO4)center dot 2(H2O)) and tricalcium phosphate (Ca-3(PO4)(2)) which are thermodynamically unstable under physiological conditions are also being explored for biomedical applications. One way of stabilizing these phases under physiological conditions is to introduce magnesium to substitute for calcium in the brushite lattice. The role of magnesium as a stabilizing agent for synthesizing brushite under physiological conditions at room temperature has been studied. Chemical analysis, Fourier transform infrared spectroscopy and X-ray diffraction have also been conducted to validate the formation of magnesium substituted brushite under physiological conditions. (C) 2010 Elsevier B.V. All rights reserved.