The effect of calcium sulfate incorporation on physiochemical and biological properties of 3D-printed mesoporous calcium silicate cement scaffolds

Development of 3D porous scaffolds with proper mechanical strength is crucial in bone tissue engineering. In this study, calcium sulfate hemihydrate (CSH) cement was functionally incorporated into mesoporous calcium silicate (MCS) through a 3D printing technique in order to improve the scaffold strength. Compared to printed MCS scaffolds, the characterizations revealed that 20% CSH incorporation had enhanced their compressive strength by 2 times via 4 weeks’ hydration. Furthermore, CSH incorporation prevented the fast pH value rise and achieved a balanced degradation rate. SEM observations showed a good apatite formation on the surfaces of both MCS and MCS/CSH scaffolds. Cellular experiments demonstrated no significant differences between MCS and MCS/CSH scaffolds in promoting osteoblast-like cell (OCT-1) adhesion, alkaline phosphatase (ALP) activity, proliferation and bone-related gene expressions. Furthermore, MCS component in the composite scaffolds exhibited sustained release behavior of dexamethasone drugs to assist bone regeneration.