Magnetic nanomaterials are increasingly impacting the field of biology and medicine. Their versatility in terms of shape, structure, composition, coating, and magnetic responsivity make them attractive for drug delivery, cell targeting and imaging. Adipose derived-mesenchymal cells (ASCs) are intensely scrutinized for tissue engineering and regenerative medicine. However, differentiation into musculoskeletal lineages can be challenging. In this paper, we show that uncoated nickel nanowires (Ni NW) partially released from their alumina membrane offer a mechanically-responsive substrate with regular topography that can be used for the delivery of magneto-mechanical stimulation. We have used a tailored protocol for improving ASCs adherence to the substrate, and showed that cells retain their characteristic fibroblastic appearance, cytoskeletal fiber distribution and good viability. We report here for the first time significant increase in osteogenic but not adipogenic differentiation of ASCs on Ni NW exposed to 4 mT magnetic field compared to non-exposed. Moreover, magnetic actuation is shown to induce ASCs osteogenesis but not adipogenesis in the absence of external biochemical cues. While these findings need to be verified in vivo, the use of Ni NW substrate for inducing osteogenesis in the absence of specific differentiation factors is attractive for bone engineering. Implant coating with similar surfaces for orthopedic and dentistry could be as well envisaged as a modality to improve osteointegration.

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A micromagnetic model based on the finite element method (FEM) is proposed in order to investigate the specific role of the magnetoelastic anisotropy in the axial magnetization reversal process of highly magnetostrictive amorphous glass-coated nanowires with cylindrical symmetry, prepared by means of rapid quenching from the melt. Using a radially distributed magnetoelastic anisotropy term, we demonstrate that both the magnitude and the shape of the anisotropy distribution affect the value of their nucleation field, and, in well-defined cases, of their switching field. The analysis provides a good explanation framework for the characteristics of magnetic bistability in magnetostrictive glass-coated amorphous nanowires, enhancing the potential applicability of these novel ferromagnetic amorphous nanosized materials.

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