Spark plasma sintering of sol–gel derived 45S5 Bioglass®-ceramics: Mechanical properties and biocompatibility evaluation

This work aims to find an efficient sintering technique and optimal sintering conditions of a novel sol–gel derived Bioglass®-ceramic powder so as to achieve much improved mechanical properties compared to conventional Bioglass®. To this end, the spark plasma sintering (SPS) technique was for the first time used to densify the sol–gel derived Bioglass®-ceramic powder. It was found that the sol–gel derived Bioglass®-ceramics sintered with the SPS technique at 950 °C for 15 min had a high Young's modulus value of ~ 110 GPa, which was comparable to that of compact bone and significantly higher than the maximal value achieved by the conventional heat treatment. Moreover, the Bioglass®-ceramic compacts sintered with SPS released alkaline ions slowly and as a result, these highly densified Bioglass®-ceramics exhibited better cytocompatibility at the early stage of cell culture testing, compared to the conventional Bioglass®. Hence, the SPS technique is recommended to be used in the process of sol–gel derived Bioglass®-ceramics and its tissue engineering scaffolds.