To avoid sudden release of fluoride, F-substituted hydroxyapatite (FHA)
porous microspheres were prepared for the treatment of F-deficiency tissues.
In the absence of any template-directing reagents, FHA microspheres with
diameters of about 30 ?m were successfully fabricated via hydrothermal
method with urea as homogeneous precipitant to regulate the nucleation,
growth and self-assembly process. Urea concentration and hydrothermal
temperature played an important role in the formation and regulation of
spherical hydroxyapatite. The synthesized FHA microspheres with large
specific surface area, large pore volume and complex porous structure were
efficient for the adsorption and long-term stable release of ionic extracts.
Concentration of F- ions in physiological salt solution was maintained in
the range of the therapeutic window without exceeding the toxic threshold
within 30 days. The ionic extracts of FHA porous microspheres promoted the
proliferation of human osteoblast-like cells (MG-63). The fabricated FHA
microspheres may be a potential candidate as bioactive fluoride-release
carriers for the treatment of osteoporosis and bone defects.