It looks like this guy managed to control the calcium intake of cells using nanomagnets. Their work, for anyone who hasn’t seen X-Men, is the first to prove that such a level of control over cells is possible. They asserted this biomagnetic control by hijacking an immune-system cell that normally mediates allergic reactions (normally, these are the guys who call for the release of histamine). Nanoparticles with iron oxide cores were used to mimic antigens in vitro, and each attached to a molecule that in turn attached to a single receptor on an immune cell. When cells bound with these particles were exposed to a weak magnetic field, the nanoparticles become magnetic and draw together, causing the cell receptors to cluster. This reaction caused the cells to take in calcium. When the magnetic field is turned off, the particles are no longer attracted to each other, the receptors move apart, and the influx of calcium stops.
Abstract: 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.
Man-machine interfaces? Not only do these guys want to be Magneto, they want to be cyborgs too. In all seriousness, though, this prospect opens up an incredible amount of doors for advances in medicine. Most medicine relies heavily upon chemical responses in cells — releasing hormones, inhibitors, and all sorts of drugs that cannot be immediately stopped if something goes wrong. However, with an immediate on/off switch (the magnetic field), we won’t have to administer a drug, then wait and see what happens. The allergic reactions or long waiting times would be a thing of the past, if we managed to correctly apply this type of technology.
Ingber’s lab began this project in response to a call by (who else?) the Defense Advanced Research Projects Agency (DARPA) for new cell-machine interfaces. He acknowledges that his work is in its early stages. In fifty years, however, he expects that there will be devices that “seamlessly interface between living cells and machines.”
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