Fluorine-substituted hydroxyapatite scaffolds hydrothermally grown from aragonitic cuttlefish bones

Porous hydroxyapatite scaffolds with different levels of fluorine substitution (46% and 85%) on the OH sites were produced via hydrothermal transformation of aragonitic cuttlefish bones at 200 degrees C and calcination at temperatures up to 1200 degrees C. The increasing level of F substitution reduces the kinetics and probably the yield of the reaction. The incorporation of F in the lattice of hydroxypatite caused a lowering of the unit cell volume due to reduction of the length of the a-axis. The crystallites formed were close in size to bone-like apatite and were orientated along the a-axis rather than the c-axis. There was evidence of AB-type carbonated apatite.