Fabrication and characterization of a new, strong and bioactive ceramic scaffold for bone regeneration

In this study we developed new ceramic compositions with competent mechanical properties at highly porous state. Strontium(Sr) doped hardystonite(Ca2ZnSi2O7) powder was mixed with aluminium oxide (Al2O3) powder of different weight fractions(0, 5, 10, 15 and 30 wt%) and the resultant ceramic labelled as SH, SH5, SH10, SH15 and SH30, respectively. Polymer sponge method was used to prepare the different ceramic scaffolds. Developed ceramics showed a unique microstructure consisted of three phases of (1) Sr doped Ca2ZnSi2O7 grains, (2) a wetting glass phase at the grain boundaries and (3) submicron crystals of ZnAl2O4(Gahnite) embedded in the glass phase. The scaffolds at 85% porosity, average pore size of 400 mu m and similar to 100% interconnectivity between the pores, achieved a compressive strength range of 0.8-4.1 MPa, modulus range of 48-173 MPa and failure strain range of 0.4-3.1%. In-vitro cytotoxicity results not only indicated the biocompatibility of these scaffolds, but also their positive effects on inducing the proliferation of primary human osteoblasts (HOBs). (C) 2013 Elsevier B.V. All rights reserved.