Porous Strontium-Containing Ceramic Granules as Bone Graft Substitutes

We have synthesized calcium phosphate-based, strontium (Sr) containing, porous ceramic granules for use as bone graft substitutes. The granules with a particle size between 1 and 2 mm and a (macro)-pore size around 200–500μm were mixed with a fibrin sealant to form a moldable composite material. The starting material with Sr contents between 0 and 100% Sr were precipitated from Ca/Sr solutions with appropriate Ca/Sr ratios, and ammonium phosphate solution using a published protocol with slight variations. A selection of the resulting powders was calcined, milled, mixed with urea as porogen and compacted into disks. These disks were fractured to result in raw granules, which were then sintered at high temperature. In preparation for in vivo implantation, the granules were mixed with fibrin sealant (ArtissTM, Baxter) to create a cohesive, moldable composite material that can be used as a bone graft substitute.