Transformable Carbonate Apatite Chains as a Novel Type of Bone Graft

Abstract

The aging global population is generating an ever‐increasing demand for bone regeneration. Various materials, including blocks, granules, and sponges, have been developed for bone regeneration. However, blocks require troublesome shaping and exhibit poor bone‐defect conformities; granules migrate into the surrounding tissues during and after filling of the defect, causing handling difficulties and complications; and sponges contain polymers that are subject to religious restrictions, lack osteoconductivity, and may cause inflammation and allergies. Herein, we present carbonate apatite chains that overcome the limitations of the conventional materials. Although carbonate apatite granules migrate, causing inflammation and ectopic calcification, the chains remain in the defects without causing any complications. The chains conform to the defect shape and transform into 3D porous structures, resulting in faster bone regeneration than that observed using granules. Thus, our findings indicate that even traditional calcium phosphates materials can be converted to state‐of‐the‐art materials via shape control.This article is protected by copyright. All rights reserved

Lamellar Septa-like Structured Carbonate Apatite Scaffolds with Layer-by-Layer Fracture Behavior for Bone Regeneration

“…Moreover, Hayashi et al reported bone formation in clinically used dense CAp granules of different sizes using the same bone defect model as that used in this study [26,46,47,52]. At week four after implantation, the bone percentages in the defects implanted with clinically used dense Cap granules that were 1-2, 0.6-1, and 0.3-0.6 mm in size were approximately 12% [45,52], 20% [26], and 21% [46], respectively. Thus, CAp-CB scaffolds can regenerate bone faster than clinically used dense CAp granules.…”

“…Thus, CAp-CB scaffolds can regenerate bone faster than clinically used dense CAp granules. Furthermore, Hayashi et al demonstrated that scaffolds with macropores, such as honeycomb, chain, and gearshaped scaffolds, promoted bone regeneration better than clinically used dense CAp granules [26,46,47,52]. These findings indicate that the lamellar septa-like cellular structure of the CAp-CB scaffold is as effective as the honeycomb, chain, and gear structures for bone regeneration.…”