Magnetoactive electrospun hybrid scaffolds based on poly(vinylidene fluoride-co-trifluoroethylene) and magnetite particles with varied sizes

The development of functional magnetoactive materials fabricated in the form of electrospun scaffolds is of paramount importance for modern medicine and pharmaceuticals. To precisely control the morphology and magnetic properties of the composite magnetoactive scaffolds, the electrospinning conditions, incorporation method of magnetic particles into the polymer solution to avoid agglomeration, and the shape/size of the particles should be thoroughly studied. In this study, hybrid magnetoactive scaffolds based on poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)), doped with either unmodified magnetite (Fe₃O₄) or magnetite particles modified with oleic acid (Fe₃O₄/OA), have been fabricated by electrospinning. Modification of magnetite particles by oleic acid results in the formation of nanosized particles in comparison with submicron-sized Fe₃O₄ particles (37 vs. 329 nm), which reveal a greater affinity to P(VDF-TrFE) due to their hydrophobic surface. Composite scaffolds prepared using 30 wt% polymer solution with 8 wt% Fe₃O₄ and Fe₃O₄/OA reveal saturation magnetization values of 9.14 and 5.8 emu/g, respectively. The saturation magnetization of composite scaffolds agrees well with the saturation magnetization of the initial magnetites. Considering the better dispersion of Fe₃O₄/OA in the polymer solution, a series of composite scaffolds with 4 and 12 wt% concentrations of magnetite have been studied. Cytotoxicity tests demonstrated that all the fabricated composite scaffolds are nontoxic to human cells. Variation of magnetite particles content in the polymer fibers enables to obtain composite scaffolds with tailored saturation magnetization, which can be potentially used as perspective magnetoactive and magnetoelectric materials for biomedical application.