Effects of Iron on Physical and Mechanical Properties, and Osteoblast Cell Interaction in β-Tricalcium Phosphate.

Iron (Fe) is a vital element and its deficiency causes abnormal bone metabolism. We investigated the effects of Fe and its concentration in β-tricalcium phosphate (β-TCP) on physicomechanical properties and in vitro proliferation and differentiation of osteoblasts. Our results showed that Fe addition at concentrations of 0.5 wt.% (0.5 Fe-TCP) and 1.0 wt.% (1.0 Fe-TCP) inhibits the β-TCP to α-TCP phase transformation at sintering temperature of 1250 °C. Addition of 0.25 wt.% Fe (0.25 Fe-TCP) increased the compressive strength of β-TCP from 167.27 ± 16.2 to 227.10 ± 19.3 MPa. After 3 days of culture, surfaces of 0.5 Fe-TCP and 1.0 Fe-TCP samples were covered by osteoblast cells, compared to that of pure and 0.25 Fe-TCP. Cells grew to confluency on all Fe-doped samples after 7 days of culture and monolayer sheet-like cellular structure was found at 11 days. Optical cell density and alkaline phosphatase activity were significantly higher on Fe-doped samples and the highest values were found in 0.5 Fe-TCP samples. Our results show that Fe concentration had significant effect on physical and mechanical properties of TCP ceramics, and also on the in vitro osteoblast cellular interactions in TCP ceramics.