Document Actions
Exploring Nano-Magnets to Fight Disease
Researchers at Children’s Hospital (Boston, Mass.) are exploring ‘magnetic control’ at the single-cell level, which researchers say could lead to finely-tuned but noninvasive treatments for disease.
Don Ingber, MD, PhD is on the team looking to use nano-magnets to diagnose and treat disease.
The work was done by 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,
The work represents the first time magnetism has been used to harness specific cellular signaling systems normally used by hormones or other natural molecules. The research was published in January’s Nature Nanotechnology, and describes how physicians and researchers devised a way to get tiny beads (30 nanometers in diameter) to bind receptor molecules to a cell’s surface.
When exposed to a magnetic field, the beads become ‘magnets,’ and the resulting pull drags the cell’s receptors into large clusters, mimicking what happens when drugs or other molecules bind to them. In turn, this clustering activates the receptors, triggering a cascade of biochemical signals that influence different cell functions.
The technology could lead to non-invasive ways of controlling drug release or physiologic processes such as heart rhythms and muscle contractions.
At 30nms, the beads provides the optimal crystal geometry to make them “superparamagnetic” – the ability to be magnetized and demagnetized over and over, researchers said.
“This technology allows us to control the behavior of living cells through magnetic forces rather than chemicals or hormones, [and it may provide a new way to interface with machines or computers in the future, opening up entirely new ways of controlling drug delivery, or making detectors that have living cells as component parts,” Ingber said.
Prior to publishing, Ingber and Mannix showed that the beads, when bound to cell receptors and exposed to a magnetic field, could stimulate an influx of calcium into the cells. (Calcium influx is a fundamental signal used by nerve cells to initiate nerve conduction, by heart and muscle cells to stimulate contractions and by other cells for secretion.) Magnetic fields alone, without the beads, had no effect.
The beads were made to attach to the mast-cell receptors by pre-coating them with antigens; these antigens then bound to antibodies that coated the receptors, similar to the way antibodies bind to antigens in the immune system. “Our goal was to have one antigen coating each bead, so that each bead would bind to just one receptor,” Mannix says.
Electrical stimuli have been used to influence the activity of nerve cells, but isn’t effective in cells that aren’t electrically excitable by nature, the researchers said. The advantage of a “nanomagnetic” control system is that it can be used in a broad range of cell types and provides a near-instantaneous on-off switch, unlike hormones and chemicals that can take minutes to hours to act and then may linger in the body. In addition, magnets are portable and have low power requirements, allowing their use in mobile or battlefield situations.
Among the innovations Ingber envisions are pacemakers that would involve an injection of nanoparticles into the heart that could be controlled magnetically. Or transdermal glucose sensors for diabetics to monitor insulin levels and even control insulin production itself.
The work represents the first time magnetism has been used to harness specific cellular signaling systems normally used by hormones or other natural molecules. The research was published in January’s Nature Nanotechnology, and describes how physicians and researchers devised a way to get tiny beads (30 nanometers in diameter) to bind receptor molecules to a cell’s surface.
When exposed to a magnetic field, the beads become ‘magnets,’ and the resulting pull drags the cell’s receptors into large clusters, mimicking what happens when drugs or other molecules bind to them. In turn, this clustering activates the receptors, triggering a cascade of biochemical signals that influence different cell functions.
The technology could lead to non-invasive ways of controlling drug release or physiologic processes such as heart rhythms and muscle contractions.
At 30nms, the beads provides the optimal crystal geometry to make them “superparamagnetic” – the ability to be magnetized and demagnetized over and over, researchers said.
“This technology allows us to control the behavior of living cells through magnetic forces rather than chemicals or hormones, [and it may provide a new way to interface with machines or computers in the future, opening up entirely new ways of controlling drug delivery, or making detectors that have living cells as component parts,” Ingber said.
Prior to publishing, Ingber and Mannix showed that the beads, when bound to cell receptors and exposed to a magnetic field, could stimulate an influx of calcium into the cells. (Calcium influx is a fundamental signal used by nerve cells to initiate nerve conduction, by heart and muscle cells to stimulate contractions and by other cells for secretion.) Magnetic fields alone, without the beads, had no effect.
The beads were made to attach to the mast-cell receptors by pre-coating them with antigens; these antigens then bound to antibodies that coated the receptors, similar to the way antibodies bind to antigens in the immune system. “Our goal was to have one antigen coating each bead, so that each bead would bind to just one receptor,” Mannix says.
Electrical stimuli have been used to influence the activity of nerve cells, but isn’t effective in cells that aren’t electrically excitable by nature, the researchers said. The advantage of a “nanomagnetic” control system is that it can be used in a broad range of cell types and provides a near-instantaneous on-off switch, unlike hormones and chemicals that can take minutes to hours to act and then may linger in the body. In addition, magnets are portable and have low power requirements, allowing their use in mobile or battlefield situations.
Among the innovations Ingber envisions are pacemakers that would involve an injection of nanoparticles into the heart that could be controlled magnetically. Or transdermal glucose sensors for diabetics to monitor insulin levels and even control insulin production itself.