Modulatory Effects of the Composition and Structure on the Osteogenic Enhancement for Superparamagnetic Scaffolds

Suisui Hao 1, # 

Yaoyi Shen 1, # 

Haoan Wu 2, # 

Jie Meng 1

Lifei Xie 1

Tao Wen 1

Ning Gu 2

Jian Liu 1, Email 

Yu Zhang 2, Email

Haiyan Xu 1, Email

1 Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China

2 School of Biological Sciences and Medical Engineering, Southeast University, Nanjing 210096, China

#These authors contributed equally to this work

Abstract

Increasing evidence shows that superparamagnetic scaffolds can enhance the osteogenesis under magnetic fields. The aim of this work is to compare the magnetization and the osteogenic enhancement of superparamagnetic scaffolds composed of different compositions with different microstructures. Herein 9 kinds of superparamagnetic scaffolds of PLA, polyurethane and gelatin were fabricated by incorporating iron oxide nanoparticles in polymeric matrices, and using the process of electrospinning, salt-leaching, and solution casting to obtain microstructure of nanofibrous, porous and smooth respectively, while hydroxyapatite nanoparticles were incorporated in all the scaffolds with the same percentage. It was showed that the magnetization behavior of the scaffolds was associated with the composition and microstructure as well as with the osteogenic enhancement of the scaffolds. The nanofibrous scaffold composed of PLA, nHA and MNPs possessed the strongest magnetization, and significantly promoted the osteogenic differentiation of pre-osteoblasts and bone marrow derived mesenchymal stem cells (bMSCs) under magnetic fields, evidenced by the upregulated gene expression of Runx2 and BMP2, the increased ALP activity, OPN and OCN of the cells. The optimal scaffold recruited more bMSCs and enhanced the osteogenic differentiation and the cross talk among the bMSCs, macrophages and fibroblasts under the magnetic field.

Modulatory Effects of the Composition and Structure on the Osteogenic Enhancement for Superparamagnetic Scaffolds