The Effect of Hydroxyapatite-Gelatin Composite with Alendronate as Injectable Bone Substitute on Various Hydroxyapatite-Based Substrate

Patients with osteoporosis in the world reached 9 million cases. The treatment for this case nowadays was using oral medication and therapy. The recent development to treat osteoporosis used injectable bone substitute. This study focused on synthesis and characterization of injectable bone substitute based on hydroxyapatite and gelatin with the addition of alendronate on various substrate. The synthesis was started by mixing hydroxyapatite, 2% (w/v) gelatin, 10% alendronate and 2% (w/v) hydroxypropyl methylcellulose to form a suspension. The substrates used in this study were HA, HA-SBF, HA-GEL, and HA-GEL-SBF. The setting time test showed that the addition of alendronate could increase the time of setting from 240-420 min in original substrate to 179-251 min in the other substrates. The density and porosity increased in all substrates which were 0.074-0.132 gr/cm3 and 28-40% for density and porosity, respectively. The pore size was 229.2-578.6 μm from morphology test. The compressive stress of the substrate increased to 1.56-3.24 MPa which was a good mechanical properties compared to compressive strength of human spine which was 0.5-50 MPa.