These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
2 files

Tuning the Magnetic Vortex State in Magnetite Nanodiscs for Remote Control of Biological Signalling

revised on 12.12.2019 and posted on 19.12.2019 by Danijela Gregurec, Alexander W. Senko, Andrey Chuvilin, Pooja Reddy, Ashwin Sankararaman, Dekel Rosenfeld, Po-Han Chiang, Francisco Garcia, Ian Tafel, Georgios Varnavides, Eugenia Ciocan, Polina Anikeeva
In this work, we demonstrate the application of anisotropic magnetite nanodiscs (MNDs) as transducers of torque to mechanosensory cells under weak, slowly varying magnetic fields (MFs). These MNDs possess a ground state vortex configuration of magnetic spins which affords greater colloidal stability due to eliminated dipole-dipole interactions characteristic of isotropic magnetic particles of similar size. We first predict vortex magnetization using micromagnetic stimulations in sub-micron anisotropic magnetite particles and then use electron holography to experimentally investigate the magnetization of MNDs 98–226 nm in diameter. When MNDs are coupled to MFs, they transition between vortex and in-plane magnetization allowing for the exertion of the torque on the pN scale, which is sufficient to activate mechanosensitive ion channels in cell membranes.


Email Address of Submitting Author


Massachusetts Institute of Technology


United States

ORCID For Submitting Author


Declaration of Conflict of Interest

P.A., A.W.S., D.G., and P.D.R. are authors of a patent application based on this work.