Letter abstract


Nature Nanotechnology 3, 36 - 40 (2008)
Published online: 23 December 2007 | doi:10.1038/nnano.2007.418

Subject Categories: Nanobiotechnology | Nanomagnetism and spintronics

Nanomagnetic actuation of receptor-mediated signal transduction

Robert J. Mannix1,4, Sanjay Kumar1,2,4, Flávia Cassiola1, Martín Montoya-Zavala1, Efraim Feinstein3, Mara Prentiss3 & Donald E. Ingber1


Complex cell behaviours are triggered by chemical ligands that bind to membrane receptors and alter intracellular signal transduction. However, future biosensors, medical devices and other microtechnologies that incorporate living cells as system components will require actuation mechanisms that are much more rapid, robust, non-invasive and easily integrated with solid-state interfaces. Here we describe a magnetic nanotechnology that activates a biochemical signalling mechanism normally switched on by binding of multivalent chemical ligands. Superparamagnetic 30-nm beads, coated with monovalent ligands and bound to transmembrane receptors, magnetize when exposed to magnetic fields, and aggregate owing to bead–bead attraction in the plane of the membrane. Associated clustering of the bound receptors acts as a nanomagnetic cellular switch that directly transduces magnetic inputs into physiological cellular outputs, with rapid system responsiveness and non-invasive dynamic control. This technique may represent a new actuator mechanism for cell-based microtechnologies and man–machine interfaces.

Top
  1. Vascular Biology Program, Departments of Pathology and Surgery, Harvard Medical School and Children's Hospital, Boston, Massachusetts 02115, USA
  2. Department of Bioengineering, University of California, Berkeley, California 94720, USA
  3. Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
  4. These authors contributed equally to this work.

Correspondence to: Donald E. Ingber1 e-mail: donald.ingber@childrens.harvard.edu