Electrostatic self-assembly of p Fe3O4 nanoparticles on graphene oxide: A co-dispersed nanosystem reinforces PLLA scaffolds

Wenjing Yang; Yancheng Zhong; Chongxian He; Shuping Peng; Youwen Yang; Fangwei Qi; Pei Feng; Cijun Shuai

doi:10.1016/j.jare.2020.04.009

Electrostatic self-assembly of p Fe₃O₄ nanoparticles on graphene oxide: A co-dispersed nanosystem reinforces PLLA scaffolds

J Adv Res. 2020 Apr 22:24:191-203. doi: 10.1016/j.jare.2020.04.009. eCollection 2020 Jul.

Authors

Wenjing Yang^{1

2}, Yancheng Zhong^{3

4}, Chongxian He¹, Shuping Peng^{3

4}, Youwen Yang¹, Fangwei Qi¹, Pei Feng², Cijun Shuai^{1

2

5}

Affiliations

¹ Institute of Bioadditive Manufacturing, Jiangxi University of Science and Technology, Nanchang 330013, China.
² State Key Laboratory of High Performance Complex Manufacturing, College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
³ School of Basic Medical Science, Central South University, Changsha 410083, China.
⁴ School of Energy and Machinery Engineering, Jiangxi University of Science and Technology, Nanchang 330013, China.
⁵ Shenzhen Institute of Information Technology, Shenzhen 518172, China.

Abstract

Cell responses and mechanical properties are vital for scaffold in bone regeneration. Fe₃O₄ nanoparticles with excellent magnetism can provide magnetic stimulation for cell growth, while graphene oxide (GO) nanosheets are commonly used as reinforcement phases due to their high strength. However, Fe₃O₄ or GO is tended to agglomerate in matrix. In present study, a novel co-dispersed Fe₃O₄-GO nanosystem was constructed through electrostatic self-assembly of positively charged Fe₃O₄ (pFe₃O₄) on negatively charged GO nanosheets. In the nanosystem, pFe₃O₄ nanoparticles and GO nanosheets support each other, which effectively alleviates the π-π stacking between GO nanosheets and magnetic attraction between pFe₃O₄ nanoparticles. Subsequently, the nanosystem was incorporated into poly _L-lactic acid (PLLA) scaffolds fabricated using selective laser sintering. The results confirmed that the pFe₃O₄-GO nanosystem exhibited a synergistic enhancement effect on stimulating cell responses by integrating the capturing effect of GO and the magnetic simulation effect of pFe₃O₄. The activity, proliferation and differentiation of cells grown on scaffolds were significantly enhanced. Moreover, the nanosystem also exhibited a synergistic enhancement effect on mechanical properties of scaffolds, since the pFe₃O₄ loaded on GO improved the efficiency of stress transfer in matrix. The tensile stress and compressive strength of scaffolds were increased by 67.1% and 132%, respectively. In addition, the nanosystem improved the degradation capability and hydrophilicity of scaffolds.

Keywords: Cell responses; Co-dispersed pFe3O4-GO nanosystem; Fe3O4; Graphene oxide; Mechanical properties.