Changes in gene expression profile of normal human fibroblasts on P(VDF-TrFE) scaffolds highly doped with Fe₃O₄-CA nanoparticles under alternating magnetic field stimulation

The design of novel hybrid magnetoactive scaffolds based on biocompatible piezopolymers and magnetic nanoparticles is of interest for medicine, mainly for tissue regeneration, because application of an external either static or alternating magnetic field to cells that settled on a magnetoactive scaffold offers an opportunity for remote control of cellular functions. This study describes fabrication of electrospun magnetoactive poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] scaffolds highly doped with 20 wt% of magnetite nanoparticles modified with citric acid (Fe₃O₄-CA). The electrospun P(VDF-TrFE)/Fe₃O₄-CA scaffolds have defect-free morphology with a fiber diameter of approximately 1 μm and contain both an electroactive β-phase (predominantly) and a lesser amount of an γ-phase. A high content of uniformly distributed Fe₃O₄-CA nanoparticles within P(VDF-TrFE) fibrous scaffolds resulted in a high saturation magnetization of 12.1 emu/g and ferrimagnetic behavior of the composite P(VDF-TrFE)/Fe₃O₄-CA scaffolds. They were proved to be biocompatible with normal human cells: normal human fibroblasts and human mesenchymal stem cells adhered to the scaffold and retained their viability. According to high-throughput RNA-sequencing data, the adhesion of fibroblasts to the scaffolds upregulated genes related to key stages of tissue regeneration such as coagulation (genes THBD and SERPINB2) and wound healing (IL24, PDGFB, F3, and PLAU) and affected TGFβ, BMP, and Wnt signaling pathways. Alternating-magnetic-field exposure of the magnetoactive P(VDF-TrFE)/Fe₃O₄-CA scaffolds with fibroblasts settled on the surface activated extracellular and intracellular cell signaling pathways.