Effect of biomimetic zinc‐containing tricalcium phosphate (Zn–TCP) on the growth and osteogenic differentiation of mesenchymal stem cells

Several studies have shown the effectiveness of zinc‐tricalcium phosphate (Zn–TCP) for bone tissue engineering. In this study, marine calcareous foraminifera possessing uniform pore size distribution were hydrothermally converted to Zn–TCP. The ability of a scaffold to combine effectively with mesenchymal stem cells (MSCs) is a key tissue‐engineering aim. In order to demonstrate the osteogenic ability of MSCs with Zn–TCP, the scaffolds were cultured in an osteogenic induction medium to elicit an osteoblastic response. The physicochemical properties of Zn–TCP were characterized by XRD, FT–IR and ICP–MS. MSCs were aspirated from rat femurs and cultured for 3 days before indirectly placing four samples into each respective well. After culture for 7, 10 and 14 days, osteoblastic differentiation was evaluated using alizarin red S stain, measurement of alkaline phosphatase (ALP) levels, cell numbers and cell viability. XRD and FT–IR patterns both showed the replacement of CO₃^2– with PO₄^3–. Chemical analysis showed zinc incorporation of 5 mol%. Significant increases in cell numbers were observed at 10 and 14 days in the Zn–TCP group, while maintaining high levels of cell viability (> 90%). ALP activity in the Zn–TCP group was statistically higher at 10 days. Alizarin red S staining also showed significantly higher levels of calcium mineralization in Zn–TCP compared with the control groups. This study showed that MSCs in the presence of biomimetically derived Zn–TCP can accelerate their differentiation to osteoblasts and could potentially be useful as a scaffold for bone tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd.