The releasing behavior and in vitro osteoinductive evaluations of dexamethasone-loaded porous calcium phosphate cements

In the present study, the effect of adding different concentrations of dexamethasone (DEX) on setting time, apatite formation and mechanical properties of micro/macroporous calcium phosphate cements (CPCs) was studied. The liberation of loaded DEX was evaluated over 0–840 h in simulated body fluid (SBF). Differentiation of mesnchymal stem cells on DEX-free and loaded CPCs were also compared by expression of bone marker proteins. The results showed that setting time decreased by adding DEX to CPCs whereas mechanical strength and conversion rate of cement reactants into apatite phase. A sustained release of DEX was observed from the loaded CPCs in which the rate of DEX release increased by introducing macroporosity and higher portion of loaded DEX. Osteogenic differentiation of MSCs on DEX-loaded CPCs was confirmed by elevated gene expressions of bone markers such as alkaline phosphatase, osteopontin and osteocalcin. Overall, the results reveal that DEX-loaded CPCs may be potentially osteoinductive material with enhanced biological functions but more in vivo evaluations are required to prove this suggestion.