Search

Moldable and injectable calcium-phosphate cements (CPCs) are material candidates for bone replacement applications. In the present study, we examined the effectiveness of sodium alginate and sodium citrate additives to the liquid phase of CPC, in improving its handling property as well as mechanical strength. The use of these additives enhanced the handling property significantly, in terms of consistency as compared to CPC without additives due to the liquefying effect caused by the adsorption of citrate ions on the cement particles. Sodium alginate and sodium citrate were added to CPC, which was set by the chelate-bonding capability of inositol phosphate, and was composed of mainly α-tricalcium phosphate (α-TCP) phase (>90%). The compressive strength of the CPC containing sodium alginate and sodium citrate was 3.4 ± 0.3 MPa, which was significantly higher than cement without additives. Furthermore, this cement exhibited favorable osteoconductivity and bioresorbability, and remained the α-TCP phase after 4-week implantation in a pig tibiae model. These results suggested that the cement is a potential candidate as a bioresorbable paste-like artificial bone. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2361-2370, 2018., (© 2017 Wiley Periodicals, Inc.)

Novel biodegradable β-tricalcium phosphate (β-TCP) cements with anti-washout properties were created on the basis of chelate-setting mechanism of inositol phosphate (IP6) using β-TCP powders. The β-TCP powders were ball-milled using ZrO₂ beads for 0-6 h in the IP6 solutions with concentrations from 0 to 10,000 ppm. The chelate-setting β-TCP cement with anti-washout property was successfully fabricated by mixing the β-TCP powder ball-milled in 3,000 ppm IP6 solution for 3 h and 2.5 mass% Na₂HPO₄ solution, and compressive strength of the cement was 13.4 ± 0.8 MPa. An in vivo study revealed that the above cement was directly in contact with host and newly formed bones without fibrous tissue layers, and was resorbed by osteoclast-like cells on the surface of the cement. The chelate-setting β-TCP cement with anti-washout property is promising for application as a novel injectable artificial bone with both biodegradability and osteoconductivity.