Cells do things (or stop doing things) because of internal
homeostatic (or other) regulatory mechanisms, or because of
communication with the “outside” via receptor sites located on
the cell membrane. To get cells to do what we want (produce more
or less of a hormone, for instance, or simply to die as in the
case of cancer cells) it would be nice to have a machine that
you point at a patient, program a few dials and buttons, and
then affect the receptor sites in that person’s cells. Well, the
production model isn’t quite ready yet, but such a device now
exists on both the drawing board and in preliminary experimental
work. Don Ingber, MD, PhD, and Robert Mannix, PhD, of Children’s
program in Vascular Biology, in collaboration with Mara
Prentiss, PhD, a physicist at Harvard University, devised a way
to get tiny beads – 30 nanometers (billionths of a meter) in
diameter – to bind to receptor molecules on the cell surface.
When exposed to a magnetic field, the beads themselves become
magnets, and pull together th