Fabrication of self‐setting β‐tricalcium phosphate granular cement

Abstract

Bone defect reconstruction would be greatly improved if β-tricalcium phosphate (β-TCP) granules had the ability to self-set without sacrificing their osteoconductivity potential. This study aimed to identify a method to permit β-TCP self-setting whilst maintaining good osteoconductivity. When mixed with acidic calcium phosphate solution, β-TCP granules were found to readily set, forming a fully interconnected porous structure. On mixing, dicalcium phosphate dihydrate crystals formed on the surface of β-TCP granules, bridging the granules and resulting in the setting reaction. The setting time of the β-TCP granular cement (β-TCP GC) was approximately 1 min and its mechanical strength, in terms of diametral tensile strength, was approximately 0.8 MPa. The β-TCP GC and β-TCP granules both showed the same level of osteoconductivity within rat calvaria bone defects. At 2 and 4 weeks post-implantation, new bone formation was comparable between the two β-TCP based bone substitutes. We conclude that β-TCP GC has excellent potential for use as a cement in bone defect reconstruction. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 800-807, 2018.

Effects of acidic calcium phosphate concentration on setting reaction and tissue response to β‐tricalcium phosphate granular cement

“…Reconstruction surgery of the rat calvarial bone defect using the β‐TCP GC was much easier compared to β‐TCP granules. Four weeks after implantation, the amount of new bone formed at the β‐TCP GC reconstructed bone defect area was comparable to those using pure β‐TCP granules . The β‐TCP GC seems to have high potential value as a bone grafting material due to its self‐setting ability, with the additional advantage of the osteoconductive behavior similar to that of β‐TCP granules.…”

“…The precipitated DCPD crystals on the surface of β‐TCP granules bridge β‐TCP granules to one another . Although the amount of DCPD increased with the concentration of acidic Ca‐P solution up to 20 mmol/L, no further DCPD increase was observed even when higher concentrations of acidic Ca‐P solution were used.…”

“…β‐TCP granules were prepared from calcium carbonate (CaCO 3 , Wako Pure Chemical Industries Ltd., Osaka, Japan) and DCPD (Wako Pure Chemical) as reported previously . In brief, CaCO 3 and DCPD powders were mixed homogeneously with 99.5% ethanol at a Ca/P ratio of 1.5 using a planetary ball mill (Pulverisette 5, Fritsch, Idar‐Oberstein, Germany) at a speed of 200 rpm for 6 h. The liquid was removed by filtration and air‐dried.…”

“…Preparation of β-TCP granules β-TCP granules were prepared from calcium carbonate (CaCO 3 , Wako Pure Chemical Industries Ltd., Osaka, Japan) and DCPD (Wako Pure Chemical) as reported previously. 9,10 In brief, CaCO 3 and DCPD powders were mixed homogeneously with 99.5% ethanol at a Ca/P ratio of 1.5 using a planetary ball mill (Pulverisette 5, Fritsch, Idar-Oberstein, Germany) at a speed of 200 rpm for 6 h. The liquid was removed by filtration and airdried. The dried powder was then placed in a stainless-steel mold (ϕ30 mm) and pressed uniaxially at 50 MPa using an oilpressure press machine (MT-50HD, NPa System, Saitama, Japan).…”

“…Four weeks after implantation, the amount of new bone formed at the β-TCP GC reconstructed bone defect area was comparable to those using pure β-TCP granules. 9 The β-TCP GC seems to have high potential value as a bone grafting material due to its self-setting ability, with the additional advantage of the osteoconductive behavior similar to that of β-TCP granules. The only potential problem could be the body's cellular response to implantation.…”