Matrix stiffness-induced platelet activation determines immunomodulation of macrophages

Ruiqiang Hang; Zhenlong Wang; Hui Wang; Yi Zhang; Yuyu Zhao; Long Bai; Xiaohong Yao

doi:10.1016/j.bioadv.2023.213356

Matrix stiffness-induced platelet activation determines immunomodulation of macrophages

Biomater Adv. 2023 May:148:213356. doi: 10.1016/j.bioadv.2023.213356. Epub 2023 Feb 23.

Authors

Ruiqiang Hang¹, Zhenlong Wang², Hui Wang³, Yi Zhang², Yuyu Zhao², Long Bai⁴, Xiaohong Yao²

Affiliations

¹ Shanxi Key Laboratory of Biomedical Metal Materials, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China. Electronic address: hangruiqiang@tyut.edu.cn.
² Shanxi Key Laboratory of Biomedical Metal Materials, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
³ Shanxi Key Laboratory of Biomedical Metal Materials, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China; Shanxi Xinhua Chemical Defense Equipment Research Institute Co., Ltd, Taiyuan 030008, China.
⁴ Organoid Research Center, Institute of Translational Medicine, Shanghai University, Shanghai 200444, China. Electronic address: bailong@shu.edu.cn.

PMID: 36848742
DOI: 10.1016/j.bioadv.2023.213356

Abstract

Although various bone defect repair materials have been used clinically, the influence of the material properties on bone repair and regeneration as well as the underlying mechanisms are not fully understood. We hypothesize that the material stiffness affects initial platelet activation during hemostasis phase, which in turn mediates subsequent osteoimmunomodulation of macrophages, finally determining clinical outcomes. To verify the hypothesis, the present work used polyacrylamide hydrogels with different stiffness (10, 70, and 260 kPa) as model materials to investigate matrix stiffness induced platelet activation behavior and its mediation on osteoimmunomodulation of macrophages. The results showed that the matrix stiffness was positively related with activation degree of platelets. However, the extracts of platelets incubated on middle-stiff matrix polarized macrophages to pro-healing M2 phenotype when compared with that on soft and stiff matrixes. ELISA results showed when compared with that on soft and stiff matrixes, the platelets incubated on middle-stiff matrix released more TGF-β and PGE₂, both of which could polarize macrophages to M2 phenotype. The M2 macrophages could promote angiogenesis of endothelial cells and osteogenesis of bone marrow mesenchymal stem cells, two important and coupled processes involved in bone repair and regeneration. These findings suggest bone repair materials with 70 kPa stiffness can mediate proper platelet activation, which can polarize macrophages to pro-healing M2 phenotype, potentially contributing to bone repair and regeneration.

Keywords: Bone repair materials; Immunomodulation; Macrophages; Matrix stiffness; Platelet activation.

MeSH terms

Endothelial Cells*
Immunomodulation
Macrophages*
Osteogenesis
Platelet Activation