Octacalcium phosphate bone substitute materials: Comparison between properties of biomaterials and other calcium phosphate materials

Abstract

Octacalcium phosphate (OCP) is a material that can be converted to hydroxyapatite (HA) under physiological environments and is considered a mineral precursor to bone apatite crystals. The structure of OCP consists of apatite layers stacked alternately with hydrated layers, and closely resembles the structure of HA. The performance of OCP as a bone substitute differs from that of HA materials in terms of their osteoconductivity and biodegradability. OCP manifests a cellular phagocytic response through osteoclastlike cells similar to that exhibited by the biodegradable material β-tricalcium phosphate (β-TCP). The use of OCP for human cranial bone defects involves using its granule or composite form with one of the natural polymers, viz., the reconstituted collagen. This review article discusses the differences and similarities in these calcium phosphate (Ca-P)-based materials from the viewpoint of the structure and their material chemistry, and attempts to elucidate why CaP materials, particularly OCP, display unique osteoconductive property.

Recent Developments of Biomaterials for Additive Manufacturing of Bone Scaffolds

“…[118] OCP is a unique calcium phosphate-based biomaterial with good osteoconductivity and biodegradability, which can be converted into hydroxyapatite under physiological conditions. [121,122] The porous OCP scaffold was successfully fabricated using 3D printing by Komlev et al, and its mechanical properties were improved from 2.5 to about 7.5 MPa by post-treatment. The in vivo results proved the scaffolds could promote bone regeneration.…”

Mutual chemical effect of autograft and octacalcium phosphate implantation on enhancing intramembranous bone regeneration

“…Mechanically mixed artificial bone substitutes and autologous bone have been clinically applied to fill in bone defects [ 51–54 ]. Although OCP is homogeneously dispersed in vehicles such as natural polymer materials, such as collagen and gelatin [ 55 , 56 ], to improve handling in some cases, a mixture of OCP and autogenous bone was implanted in the defects without any vehicle in this study. Thus, this study enabled us to estimate the direct bone tissue response without using vehicles.…”

Stem Cell-Friendly Scaffold Biomaterials: Applications for Bone Tissue Engineering and Regenerative Medicine

“…Higher biodegradability Innate brittleness makes it hard to sustain its shape Kamakura et al, 1999;Dvorak et al, 2004;Bigi et al, 2005;Wang et al, 2015;Suzuki et al, 2020;Yanagisawa et al, 2020 Bioglass BG SiO 2 Na 2 OCaOP 2 O 5 Osteoconduction Osteoinduction Biocompatibility…”

“…Although OCP has many suitable properties as a bone substitute, its innate brittleness results in difficulty in sustaining its shape and therefore limits its clinical applications. Nonetheless, OCP combined with natural polymers is explored to treat bone defects (Suzuki et al, 2020).…”