Page 453 - IJB-10-2

International

Journal of Bioprinting

RESEARCH ARTICLE
Roles of pore architecture of artificial bone

grafts in invasion competition between
bone and fibrous tissue and orientation

of regenerated bone

Keigo Shibahara, Koichiro Hayashi, * Yasuharu Nakashima,
1,2
2
1
and Kunio Ishikawa 1
1 Department of Biomaterials Faculty of Dental Science, Kyushu University, Maidashi, Higashi-ku,
Fukuoka, Japan
2 Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University,
Maidashi, Higashi-ku, Fukuoka, Japan
(This article belongs to the Special Issue: Advanced Biomaterials for 3D Printing and Healthcare Application)

Abstract

In the reconstruction of bone defects close to soft tissue, preventing the invasion
of fibrous tissue into the bone defect is key to successful bone reconstruction. In
this study, we clarified the effects of the pore architecture of artificial bone grafts
on the penetration of bone and fibrous tissue, and the orientation of regenerated
bone. Carbonate apatite grafts with uniaxial pores along the long- (L-graft) or short-
axis (S-graft) direction of the graft and biaxial pores along the long- and short-axes
(LS-graft) were used. These grafts were implanted in bone defects created by rabbit
*Corresponding author: ulnae amputation. The pores of the L-, S-, and LS-grafts opened into the bone stumps,
Koichiro Hayashi muscles, and bone stumps and muscles together, respectively. In the L-graft, the graft
(khayashi@dent.kyushu-u.ac.jp)
pores developed bone from the bone stump to the graft center, while preventing
Citation: Shibahara K, Hayashi K, excessive invasion of fibrous tissue. In S- and LS-grafts, the graft pores along the short
Nakashima Y, Ishikawa K. Roles axis allowed the invasion of fibrous tissue into the grafts. Consequently, although the
of pore architecture of artificial
bone grafts in invasion competition bone grew to the edge regions in these grafts, further bone ingrowth was inhibited
between bone and fibrous tissue by the fibrous tissue. Furthermore, the pore architecture of the grafts affected the
and orientation of regenerated bone. orientation of the regenerated bone. The degree of orientation of the bone formed
Int J Bioprint. 2024;10(2):2323.
doi: 10.36922/ijb.2323 in the L- and S-grafts was 1.6-fold higher than that formed in the LS-grafts. Thus,
controlling the pore architecture allowed the growth of bone to predominate over
Received: November 28, 2023
Accepted: January 22, 2024 that of fibrous tissue and induced the formation of bone with an ordered orientation.
Published Online: March 1, 2024
Copyright: © 2024 Author(s). Keywords: Pore architecture; Bone; Apatite; Tissue regeneration; Graft
This is an Open Access article
distributed under the terms of the
Creative Commons Attribution
License, permitting distribution,
and reproduction in any medium, 1. Introduction
provided the original work is
properly cited. Owing to the aging global population, the incidence of non-union bone fractures is
1-4
Publisher’s Note: AccScience increasing. Non-union bone fractures reduce quality of life and impose an economic
Publishing remains neutral with burden on patients. In terms of the pathology of non-unions, fibrous tissue is always
3,4
regard to jurisdictional claims in 5,6
published maps and institutional present in the defective region and prevents bone regeneration. Notably, in bone defects
affiliations. close to the soft tissue, such as fractures of long bones with segmental bone loss, fibrous

Volume 10 Issue 2 (2024) 445 doi: 10.36922/ijb.2323