Page 136 - IJB-9-5

International Journal of Bioprinting

RESEARCH ARTICLE
Pore size-mediated macrophage M1 to M2

transition affects osseointegration of 3D-printed
PEEK scaffolds

Xiaopeng Yang , Jianbo Gao , Shenyu Yang , Yan Wu , Huilong Liu ,
2
1,2
2
2
2
Danyang Su , Dichen Li *
2
1
1 State Key Lab for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049,
China
2 The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
Abstract
Increasing evidence indicates that macrophages play an important role in angiogenesis
and bone regeneration. Because the phenotypic polarization of macrophage is
extremely sensitive to the pore size of materials, poly(ether-ether-ketone) (PEEK)
scaffolds with pore sizes of 0, 200, and 400 μm were prepared, and the influence
of pore size-mediated macrophage polarization on subsequent angiogenesis and
osteogenesis was examined. The interaction results of macrophages and scaffolds
indicated that macrophages were responsive to the pore size of three-dimensional
(3D)-printed PEEK scaffolds, and large pore size scaffolds showed greater potential
in inducing M1 to M2 transition of macrophage and enhanced macrophage
secretion of high concentrations of osteogenesis-related and angiogenesis-related
cytokines. When human umbilical vein endothelial cells (HUVECs) and bone marrow
mesenchymal stem cells (BMSCs) were cultured in the conditioned medium derived
*Corresponding author:
Dichen Li (dcli@mail.xjtu.edu.cn) from co-culture of macrophages and scaffolds, HUVECs showed good angiogenic
responses in terms of cell migration and angiogenic gene expression, while BMSCs
Citation: Yang X, Gao J, Yang S,
et al., 2023, Pore size-mediated showed good osteogenic differentiation effect in in vitro mineralization and
macrophage M1 to M2 transition osteogenesis-related gene expression. The results of bone defect repair showed that
affects osseointegration of the bone volume/total volume ratio and trabecular thickness of the large pore size
3D-printed PEEK scaffolds.
Int J Bioprint, 9(5): 755. PEEK scaffold were significantly higher, and it had better biomechanical properties
https://doi.org/10.18063/ijb.755 and achieved a better osseointegration effect. Our data demonstrate that large-pore
PEEK scaffolds promote angiogenesis and osteogenic differentiation in vitro and
Received: December 1, 2022
Accepted: February 12, 2023 osseointegration in vivo, most likely because scaffolds with larger pore size are able
Published Online: May 17, 2023 to mediate a higher degree of M1 to M2 transition in macrophages.
Copyright: © 2023 Author(s).
This is an Open Access article
distributed under the terms of the Keywords: PEEK; 3D printing; Pore size, Macrophage, Osseointegration
Creative Commons Attribution
License, permitting distribution,
and reproduction in any medium,
provided the original work is
properly cited. 1. Introduction
Publisher’s Note: Whioce In the past decades, in order to improve the osseointegration ability of bone repair
Publishing remains neutral with materials with host bone, researchers have mainly focused on designing or modifying
regard to jurisdictional claims in bone repair materials to induce differentiation of bone marrow mesenchymal stem
published maps and institutional
affiliations. cells (BMSCs) into osteoblasts [1,2] . However, when the bone repair material is implanted

Volume 9 Issue 5 (2023) 128 https://doi.org/10.18063/ijb.755