Enhanced osteoinduction of electrospun scaffolds with assemblies of hematite nanoparticles as a bioactive interface

Abstract

Shanshan Ma,1,* Zibin Wang,2,* Yu Guo,1 Peng Wang,3 Zukun Yang,1 Liping Han,1 Jianfei Sun,4 Yang Xia1,4 1Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, Jiangsu 210029, China; 2Analysis and Test Center, Nanjing Medical University, Nanjing, Jiangsu 211166, China; 3Department of Sports Medicine and Adult Reconstructive Surgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, Jiangsu 210008, China; 4Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China *These authors contributed equally to this work Purpose: Electrospun scaffolds have been studied extensively for their potential use in bone tissue engineering. However, their hydrophobicity and relatively low matrix stiffness constrain their osteoinduction capacities. In the present study, we studied polymer electrospun scaffolds coated with hydrophilic hematite nanoparticles (αFeNPs) constructed using layer-by-layer (LbL) assembly to construct a bioactive interface between the scaffolds and cells, to improve the osteoinduction capacities of the scaffolds.Materials and methods: The morphology of the αFeNPs was assessed. Surface properties of the scaffolds were tested by X-ray photoelectron spectroscopy (XPS), surface water contact angle, and in vitro protein adsorption test. The stiffness of the coating was tested using an atomic force microscope (AFM). In vitro cell assays were performed using rat adipose-derived stem cells (ADSCs).Results: Morphology characterizations showed that αFeNPs assembled on the surface of the scaffold, where the nano assemblies improved hydrophilicity and increased surface roughness, with increased surface stiffness. Enhanced initial ADSC cell spread was found in the nano assembled groups. Significant enhancements in osteogenic differentiation, represented by enhanced alkaline phosphatase (ALP) activities, elevated expression of osteogenic marker genes, and increased mineral synthesis by the seeded ADSCs, were detected. The influencing factors were attributed to the better hydrophilicity, rougher surface topography, and harder interface stiffness. In addition, the presence of nanoparticles was believed to provide better cell adhesion sites.Conclusion: The results suggested that the construction of a bioactive interface by LbL assembly using αFeNPs on traditional scaffolds should be a promising method for bone tissue engineering. Keywords: layer-by-layer assembly, osteogenesis, nanotechnology, bone tissue engineering, surface, αFeNPs  

Keywords

• layer-by-layer assembly
• osteogenesis
• nanotechnology
• bone tissue engineering
• interface.