Biomimetic Octacalcium Phosphate Bone Has Superior Bone Regeneration Ability Compared to Xenogeneic or Synthetic Bone.

Jooseong Kim,Sukyoung Kim,Inhwan Song

doi:10.3390/ma14185300

Abstract

Octacalcium phosphate (OCP) is a precursor of biological apatite crystals that has attracted attention as a possible bone substitute. On the other hand, few studies have examined this material at the experimental level due to the limitations on OCP mass production. Recently, mass production technology of OCP was developed, and the launch of OCP bone substitutes is occurring. In this study, the bone regeneration capacity of OCP products was compared with two of the most clinically used materials: heat-treated bovine bone (BHA) and sintered biphasic calcium phosphate (BCP). Twelve rabbits were used, and defects in each tibia were filled with OCP, BHA, BCP, and left unfilled as control (CON). The tibias were harvested at 4 and 12 weeks, and 15 μm slides were prepared using the diamond grinding method after being embedded in resin. Histological and histomorphometric analyses were performed to evaluate the bone regeneration ability and mechanism. The OCP showed significantly higher resorption and new bone formation in both periods analysed (p < 0.05). Overall, OCP bone substitutes can enhance bone regeneration significantly by activating osteoblasts and a rapid phase transition of OCP crystals to biological apatite crystals (mineralization), as well as providing additional space for new bone formation by rapid resorption.

Highlights

Autogenous bone is still the best option for regenerating bone defects because it meets all the indicated requirements of an ideal bone graft material for osteoinduction and osteoconduction [1,2,3]
Bio-Oss (Geistlich Pharma AG, Wolhusen Switzerland), which is produced by deproteination at high temperatures, favors the proliferation of blood vessels and bone cell migration through the interconnecting micropores. Another comparative testing sample was a biphasic calcium phosphate (BCP) product (MBCP+) that consists of 20:80% of HA and β-tricalcium phosphate (β-TCP)
The Octacalcium phosphate (OCP) sample, which consisted mainly of OCP, had the fastest resorption rate in the in vivo test environment compared to the rates for BHA, which was composed mainly of low crystalline HA and MCP, which was comprised of high crystalline HA and β-TCP

Summary

Introduction

Autogenous bone is still the best option for regenerating bone defects because it meets all the indicated requirements of an ideal bone graft material for osteoinduction and osteoconduction [1,2,3]. Synthetic bone or biomimetic bone materials as alternatives to autogenous bone have been evaluated as artificial bone in orthopedics and dentistry These alternative materials should provide a variety of shapes and sizes with mechanical strength and biocompatibility suitable for use in the regeneration of bone defect sites. Numerous physicochemical features of scaffolds, such as surface chemistry, surface roughness, topography, mechanical properties, and interfacial free energy (hydrophobic/hydrophilic balance) are important for cell attachment, proliferation, and differentiation. These factors are critical to the overall biocompatibility and bioactivity of a particular material [5,6,7]

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Conclusion