Characterization and in vitro evaluation of biphasic α-tricalcium phosphate/β-tricalcium phosphate cement.

Biphasic calcium phosphate consisting of hydroxyapatite (HA) and β-tricalcium phosphate(β-TCP) is an excellent bone substitute with controllable bioresorbability. Fabrication of biphasic calcium phosphate with self-setting ability is expected to enhance its potential application as bone substitute. In this study, mixtures of α-TCP and β-TCP with various compositions were prepared through α-β phase transition of α-TCP powder at 1000°C for various periods. These powders were mixed with 0.25M Na2HPO4 at a P/L ratio of 2, and then hardened at 37°C at 100% RH for up to 24h. Material properties of biphasic HA/β-TCP cement with different α-TCP/β-TCP composition were characterized. These cements were also evaluated with respect to cell response in vitro using MC3T3-E1 cell lines. In conclusion, mechanical and biological properties of HA/β-TCP cement could be controlled by changing the heat treatment time of α-TCP powder at 1000°C. In vitro results indicated that cell proliferation and ALP activity increased with increase β-TCP content.