Bioactive Star Gels

Star gels hybrid materials, suitable for use in bone repair, have been synthesized by the sol−gel method, incorporating a calcium alkoxide to the synthesis process. To determine the network connectivity and the Ca 2+ cation location into the hybrid network, the physical and chemical properties of star gels with different compositions have been studied. In vitro bioactivity tests evidence that the star gels develop an apatite-like phase on their surface in contact with simulated body fluid, although this property depends on the Si/Ca ratio. Finally, the study of mechanical properties demonstrated that star gels are less rigid than conventional bioactive glasses, show similar fracture toughness values than cortical bone, and point to excellent long-term fatigue behavior.