Calcium orthophosphates, such as hydroxyapatite (Ca5(PO4)3OH) (HA), have long been employed as bone graft materials. Recent work has suggested that calcium pyrophosphate (Ca2P2O7) (CaPy) may strongly stimulate bone deposition. In this study we compare calcium orthophosphate and pyrophosphate precipitates as suitable bone regeneration materials. As well as HA, two forms of pyrophosphate precipitate were compared in this work: amorphous calcium pyrophosphate (amCaPy) and star particle calcium pyrophosphate (stCaPy). Briefly, 0.15M Na4P2O7·10H2O and 0.3M Ca2Cl·2H2O solutions of equivalent volume were combined and left to age before performing a series of filtration and re-suspension steps upon the precipitate. Drying yielded amCaPy powder. stAmPy was produced by the same procedure however the pH of the starting solutions were altered to pH7 before combination.Background
Methods
