a1 Department of Materials Science and Engineering and Center for Bone and Tissue Repair and Regeneration, Missouri University of Science and Technology, Rolla, MO 65409, USA.
Bioactive glass is an attractive scaffold material for use in filling bone defects because of its widely recognized ability to support the growth of bone cells and to bond firmly with hard and soft tissue. Use of bioactive glasses in the form of porous three-dimensional scaffolds for bone repair applications has been receiving considerable interest in recent years. However, bioactive glass scaffolds have been limited to the repair of low-load bone defects because of their low strength. In the present work, porous and strong bioactive glass scaffolds with an oriented microstructure were prepared by unidirectional freezing of camphene-based suspensions, and evaluated for their ability to regenerate bone in a non-healing rat calvarial defect model. Scaffolds of 13-93 glass (53SiO2, 6Na2O, 12K2O, 5MgO, 20CaO, 4P2O5; wt%) with a porosity of 50% and columnar pores of diameter 50–150 μm showed a compressive strength of 47 ± 5 MPa and an elastic modulus of 11 ± 3 GPa. Total bone regeneration in the oriented scaffolds, 18% after implantation for 12 weeks to 24% after 24 weeks, was not significantly different from that in 13-93 scaffolds with a microstructure similar to that of dry human trabecular bone (control group). The results indicated that these oriented bioactive glass (13-93) scaffolds could potentially be used in the regeneration of loaded bone.