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

Abstract

Calcium carbonate-based bone substitutes derived from natural coral exoskeleton (aragonite) are resorbed and remodeled faster than calcium phosphate-based substitutes. However, coral species with structures appropriate for use as bone substitutes are very limited. Therefore, it is important to evaluate potential of artificial calcium carbonate ceramics as a bone substitute. In this study, calcium carbonate granules with various porosities and pore sizes were prepared by sintering a highly pure (>99.98%) calcium carbonate powder (calcite), and their resorption properties and bone formation abilities were examined in vivo for the first time. The sintered calcium carbonate was resorbed faster than β-tricalcium phosphate, which has a similar structure. However, sintered calcium carbonate did not promote new bone formation during long-term implantation. Furthermore, both resorption and new bone formation were affected by the pore structure. The optimal structures of the artificially sintered calcium carbonate bone substitute were also discussed.

Calcium carbonate: controlled synthesis, surface functionalization, and nanostructured materials

“…226 Highly pure and monodisperse calcite can be assembled without any sintering aid under flowing CO 2 at atmospheric pressure to fabricate porous CaCO 3 ceramics with porosities in the range of 10–75%. 227 The obtained CaCO 3 ceramics exhibit faster resorption than β-tricalcium phosphate. Furthermore, both resorption and new bone formation are affected by the pore structure.…”

“…225 In addition, CaCO 3 cements exhibit excellent biodegradability and biocompatibility properties compared to other synthetic bone substitutive cements such as CaP, tricalcium phosphate, and hydroxyapatite, both in vitro and in vivo , and they can enhance gene expression in specific osteogenic markers. 226,227 Moreover, CaCO 3 is not only a possible calcium source for the preparation of calcium-based materials such as hydroxyapatite and other CaP salts due to its fast biodegradability, 228 but is also a functional additive that can be incorporated into CaP-based cements to improve their performances in bioresorbability and bone formation. 225,229 The slow resorption rate of bone graft substitutes, such as CaP cements and apatite, inhibits their replacement by new bone tissues and ultimate bone defect repair.…”

“…234 Porous CaCO 3 ceramics can be obtained via strategic methods, such as the carbonation of Ca(OH) 2 , 234 introduction of sintering agents at low melting temperature, 226 and sintering under a CO 2 atmosphere. 227 CaCO 3 with macropores of over 100 μm can be prepared using NaCl as a pore generator by means of the carbonation of Ca(OH) 2 /NaCl composite solutions. 234 CaCO 3 composite ceramics were fabricated via the fast sintering of CaCO 3 at 650 °C using the sintering agent phosphate-based glass (50P 2 O 5 ·18CaO·12MgO·20Na 2 O), which has a low melting temperature.…”

Bone augmentation with a prototype coral exoskeleton-derived bone replacement material applied to experimental one-wall infrabony defects created in alveolar bone

“…The FTIR peak at approximately 1,082 cm −1 was observed only in the spectrum of calcium carbonate of the aragonite phase, whose CO 3 2− ions were inactive in the infrared region 29) . Calcium carbonate bone replacement materials derived from natural coral exoskeleton (aragonite) were resorbed and reconstructed more quickly than were calcium phosphate bone replacement materials 30) . Similar to coral exoskeleton-derived bone replacement materials commercially available in Europe and the United States, CG may promote bone regeneration in the alveolar and periapical bone.…”

Fabrication of interconnected porous Ag substituted octacalcium phosphate blocks based on a dissolution-precipitation reaction

“…The attachment of an interconnected porous structure (i.e., foam) to a scaffold has been an effective way to accelerate the replacement of the scaffold to bone, because the attachment occurs only on the surface of the scaffold [ 1 – 3 ]. Foams have been known to enhance tissue response because their interconnected pores allow cells and tissues to penetrate the interior of the scaffold; thereby, facilitating the supply of vital nutrients by vascular ingrowth [ 1 , 4 – 6 ].…”