Fabrication and osteogenic differentiation performance of the electrospun magnetic P(VDF-TrFE)/Fe3O4 composite fibrous membranes

Abstract

The design of magnetoactive hybrid scaffolds based on biocompatible piezoelectric polymers and magnetic nanoparticles (NPs) holds great promise for advanced bone tissue regeneration applications. In this study, electrospun magnetoactive poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] composite fibrous membranes doped with different concentrations of oleic acid-modified Fe₃O₄ (Fe₃O₄-OA) NPs were successfully fabricated via the electrospinning technology. The as-prepared P(VDF-TrFE)/Fe₃O₄-OA composite membranes exhibited a uniform fibrous morphology with an average fiber diameter of approximately 0.2 µm, and the piezoelectric crystalline β-phase was predominant. The homogeneous dispersion of Fe₃O₄-OA NPs endowed the composite fibrous membranes with typical ferromagnetic behaviour and tunable saturation magnetisation. In vitro biological evaluations confirmed the excellent biocompatibility of the composite membranes with bone marrow mesenchymal stem cells (BMSCs). CCK-8 assays indicated that the viability of BMSCs cultured on all composite membrane groups increased over time, and live/dead staining further verified that all composite membranes supported high BMSC viability. F-actin staining results revealed that BMSCs could effectively attach and spread on the composite membranes with well-developed cytoskeletal structures. Moreover, the osteogenic differentiation potential of the BMSCs on the composite membranes was systematically evaluated at the early, middle and late stages of osteogenic induction. Alkaline phosphatase (ALP) activity assays revealed that the composite membranes containing Fe₃O₄-OA NPs exhibited significantly elevated ALP activity compared with the pure P(VDF-TrFE) membrane, and RUNX2 immunofluorescence staining confirmed enhanced early osteogenic transcriptional activation in the BMSCs cultured on the Fe₃O₄-OA-doped composite membranes. Collectively, these findings suggest that the electrospun magnetic P(VDF-TrFE)/Fe₃O₄-OA composite fibrous membranes exhibit good cytocompatibility and support the osteogenic differentiation of BMSCs, indicating their potential as scaffold materials for bone tissue engineering.