Crystallization behavior mediated by silicon in the hydration reaction of polycrystalline tricalcium phosphate cements

Calcium phosphate bone cement (CPC) has the advantages of good biocompatibility, injectability and arbitrary molding, and is an ideal bone repair material. However, CPC lacks good biodegradability, which affects its application in bone repair. In our work, we improved the degradation performance of CPC through two approaches: 1. By controlling the sintering process, we synthesized tricalcium phosphate (TCP) in situ as hydration raw material and made its hydration products generate dibasic calcium phosphate (DCPD). 2. Si was introduced as an inducer of hydration crystallization behavior of CPC, and the hydration products showed a long flake-like morphology. In addition, the introduction of moderate amount of Si as a nucleating agent affected the growth and porosity of the crystals inside the CPC, and improved the mechanical properties of the CPC; The coagulation time was shortened and did not have a great impact on injectability. The strength was increased from 17 +/- 1.23 MPa to 32.53 +/- 8.51 Mpa, an enhancement of about 91.35%. It is proposed that Si played a role in the crystal nucleus during hydration and induced the generation of DCPD crystal phase. Then, the mass retention rate of the biphasic CPC continues to decline in the whole degradation process, which shows the sustainable degradation behavior.

Automated summary

Adding a moderate amount of Si can improve the biodegradability and mechanical properties of CPC, without affecting injectability.