Preparation and evaluation of bioresorbable porous octacalcium phosphate bone precursor

Abstract

Reaction of mono calcium phosphate monohydrate (MCPM) and calcium carbonate at 36.5°C was applied to prepare octacalcium phosphate (OCP) porous compact expected to be a bioresorbable bone precursor in accord with autologous bone recycling process. XRD analysis confirmed that intermediate product of porous dicalcium phosphate dihydrate (DCPD) compact is synthesized practically in the first period of 2 hours, and that DCPD crystalline is reasonably decomposed into OCP through the hydrolysis reaction within 7 days. The pH value of phosphate buffered solution exerts an influence on the CO2 gas evolution reaction and hence the transformation rate of DCPD crystalline into OCP. OCP porous compacts were evaluated in simulated body fluid (SBF) for its transformation ability to hydroxyapatite (HAp). SEM micrographs, XRD and EDS analyses demonstrated that petaloid shaped calcium-deficient HAp should be crystallized on the basis of the bone-like apatite layers in OCP crystalline structure.