http://www.davidicke.com/forum/archive/index.php/t-617-p-4.html
Nanoparticles allow researchers to initiate biochemical events at will.
Friday, January 18, 2008
For the first time, researchers have demonstrated a means of controlling cell functions with a physical, rather than chemical, signal. Using a magnetic field to pull together tiny beads targeted to particular cell receptors, Harvard researchers made cells take up calcium, and then stop, then take it up again.
Ingber's group demonstrated its method for biomagnetic control using a type of immune-system cell that mediates allergic reactions. Targeted nanoparticles with iron oxide cores were used to mimic antigens in vitro. Each is attached to a molecule that in turn can attach to a single receptor on an immune cell. When Ingber exposes cells bound with these particles to a weak magnetic field, the nanoparticles become magnetic and draw together, pulling the attached cell receptors into clusters. This causes the cells to take in calcium. (In the body, this would initiate a chain of events that leads the cells to release histamine.) 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.
Magnetic pacemakers could use cells instead of electrodes to send electrical pulses to the heart.
Ingber, who began the project in response to a call by the Defense Advanced Research Projects Agency for new cell-machine interfaces, 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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