Influence of polarization on the bioactivity of nanopowders of hydroxyapatite

Polarization can accelerate the bioactivity of HAp immersed in an SBF solution. However a careful choice of polarization conditions has to be made. One relevant issue is to have long relaxation times of the polarization and this is related to the amount of water in Hap, which was to be kept as low as possible during poling. It was shown that the precipitation mechanism needs negative charges on the Hap surface. Under positive charge the mechanism is inhibited.