Evaluation of silver ion bioavailability from silver doped hydroxyapatite

The in vitro behavior of silver doped hydroxyapatite (HAp/Ag) prepared by two wet precipitation routes were studied in water and simulated body fluid (SBF). In order to evaluate the silver ion bioavailability from HAp/Ag, the samples were soaked in SBF or water and kept at 37°C for fixed periods of time up to one year. After fixed periods of time, analyses of SBF and water solutions were performed and silver ion concentration within the solutions determined. According to silver release data from dense and porous HAp/Ag ceramic scaffolds, release rate of silver ions were reduced in water as the ion exchange there was slower compared to SBF solution. X-ray diffraction and scanning electron microscopy analysis approved the formation of hydroxyapatite type layer on the surfaces of scaffolds after one year soaking in SBF.