Biomaterials

Biography

Biography: Eddy Eddy

Abstract

Introduction: Previously, we had proposed that beta tricalcium phosphate granular cement (β-TCPGC) is useful to prevent flowing out of the β-TCP granules from the bone defect. When the β-TCP granules were mixed with acidic calcium phosphate solution, it set to form interconnected porous structure. Although it seems promising, β-TCP granules need to be mixed with the acidic calcium phosphate solution. Calcium sulfate hemihydrate (CSH) has self-setting ability by converting to calcium sulfate dihydrate (CSD) when exposed to water. Furthermore, CSD is the component of Osteoset^®, which is a commercially available as a bone substitute. In this study, we fabricated CSH coated β-TCP granules through dissolution-precipitation method. This setting ability could inhibit the flowing out of the β-TCP granules from the bone defect.

Experimental Method: β-TCP granules were immersed in NaHSO₄ solution for 1, 3, 5 and 7 days at 70^oC. The samples were then heated at 120^oC for 4 hours. β-TCPGC was prepared by mixing the granules with saline solution at a L/P ratio of 0:3 and identified by XRD and SEM. The mechanical strength of the β-TCPGC was measured as a DTS by universal testing machine. β-TCPGC was implanted in rabbit femur for 4 weeks and the percentage of newly formed bone was calculated from histological analysis.

Results: β-TCP granules immersed in NaHSO₄ solution were coated by CSD and CSD became CSH after heating at 120ºC for 4 hours. CSH coated β-TCP granules mixed with saline solution were set and DTS value of β-TCPGC with 75 wt.% of CSH was 0.8±0.1 MPa. The percentage of newly formed bone of β-TCPGC with 75 wt.% of CSH was 28.7±0.5%. Meanwhile, β-TCP granules without coating were 19.9±1.1%.

Conclusion: CSH coated β-TCP were successfully fabricated and formed interconnected porous structure with good mechanical strength after mixing with saline solution.