Fabrication of interconnected porous calcite by bridging calcite granules with dicalcium phosphate dihydrate and their histological evaluation

Abstract

Interconnected porous calcite has attracted attention as an artificial bone replacement material and as a precursor for the fabrication of carbonate apatite, which is also an artificial bone replacement material. In this study, calcite granules were exposed to acidic calcium phosphate solution, and the feasibility of fabricating interconnected porous calcite using this process was evaluated. No setting reaction was observed under the nonloading condition. In contrast, under loading conditions, calcite granules were bridged with dicalcium phosphate dihydrate crystals, and the calcite granules set into interconnected porous calcite foam. When applied 0.4 MPa of loading pressure during sample preparation, compressive strength of the obtained interconnected porous calcite was ∼1.5 MPa. The exposure of the calcite granules to acidic calcium phosphate solution under loading conditions was the key for the setting reaction to occur. This is because calcite granules cannot contact one another under the nonloading condition because of bubble formation on the surfaces of the calcite granules. The interconnected porous calcite revealed excellent tissue response, and new bone was able to penetrate into the porous calcite 2 weeks after implantation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A 104A: 652-658, 2016.

Fabrication and evaluation of carbonate apatite-coated calcium carbonate bone substitutes for bone tissue engineering

“…In vivo observations in all groups revealed much more cell‐mediated granule resorption in the bone tissue, because all granules did not show remarkable dissolution in diffusion chambers under the acellular condition (Figures and ). MNGCs found on granules in rabbit femoral defects were most likely to contribute to material resorption (Figure ), as previously observed on CaCO 3 blocks in the rabbit femur (K. Ishikawa et al, ) and CO 3 Ap granules in the rat tibia and rabbit femur (Ayukawa et al, ; Hasegawa, Doi, & Uchida, ). CO 3 Ap clearly showed less resorption even in bone tissue compared with CaCO 3 (Figures ).…”

“…After immersion, the granules were separated by filtration. The concentration of Ca 2+ in the physiological saline solution was calculated by ICP‐AES (K. Ishikawa, Koga, Tsuru, & Takahashi, ).…”

<i>In vivo</i> bioresorbability and bone formation ability of sintered highly pure calcium carbonate granules

“…Coral harvesting is costly and may damage the surrounding marine environment 19) . Several studies have focused on fabricating calcium carbonate blocks and bulk composites for use as biomaterials, such as calcite block from calcium hydroxide compact 20) and gypsum block 21) , interconnected porous calcite bridged by dicalcium phosphate dehydrate 22,23) , calcium carbonate with phosphate glasses 24,25) , calcium carbonate with gypsum 26) , with poly(lactic-glycolic acid) 27) , with poly(lactic acid) 28) , and calcium carbonate coating on titanium 29,30) , due to their high bioresorbability. Attempts have also been made to use porous or hollow calcium carbonate in biomedical applications 23,[31][32][33][34] .…”

Validity check of easy-to-use torsion test method for bioceramics

“…In order to avoid this problem, porous apatite ceramics have been developed, in which cells can penetrate into the pores and proliferate. And artificial bones (porous apatite ceramics) directly bind to natural bone at an early date [3][4][5][6][7][8][9][10]. This makes it clear that bioceramics must be strong enough not to be fractured or seriously damaged, even when subjected to abrupt loading during a clinical course.…”