Forced- and Self-Rotation of Magnetic Nanorods Assembly at the Cell Membrane: A Biomagnetic Torsion Pendulum

In order to give insights into how anisotropic nano-objects interact with living cell membranes, and possibly self-assemble, we designed magnetic nanorods with average size around 100 nm x 1$\mu$m by assembling iron oxide nanocubes within a polymeric matrix under a magnetic field. We then explored the nano-bio interface at the cell membrane under the influence of a rotating magnetic field. We observed a complex structuration of the nanorods intertwined with the membranes. Unexpectedly, after a magnetic rotating stimulation, the resulting macrorods were able to rotate freely for multiple rotations, revealing the creation of a bio-magnetic torsion pendulum.