Osteogenesis/Angiogenesis Properties of Pulp Cell on Injectable Silica Doped-TCP Cement

Objective:  β-tricalcium phosphate (β-TCP) is an osteoconductive material in the clinical. In this study, we have doped silica (Si) into β-TCP and enhanced its bioactive and osteostimulative properties. To check its effectiveness, a series of Si-doped with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Method: The reagent grade SiO₂ and β-TCP powders were used as matrix materials and sintered at 1,400°C for 3 h using a high-temperature furnace. Formation of the diametral tensile strength, ions released and weight loss of cements was considered after immersion. In addition, we also examined the behavior of human dental pulp cell (hDPCs) cultured on Si-doped β-TCP cements.  A one-way analysis of variance statistical analysis was used to evaluate the significance of the differences between the means in the measured data. Result: The results showed that setting time and injectability of the Si-doped β-TCP cements were decreased as the Si content was increased. At the end of the immersion point, weight losses of 30.1%, 36.9%, 48.1%, and 55.3% were observed for the cement doping 0%, 10%, 20%, and 30% Si into β-TCP cements, respectively. In vitrocell experiments shows that the Si-rich cements promote human dental pulp cells (hDPCs) proliferation and differentiation. However, when the CS quantity in the composite is more than 20%, the amount of cells and osteogenesis protein of hDPCs were stimulated by Si released from Si-doped β-TCP cements. Conclusion: The degradation of β-TCP and osteogenesis of Si gives strong reason to believe that these Si-doped β-TCP cements may prove to be promising bone repair materials.