January 9, 2008
Bioengineering Assistant Professor Sanjay Kumar, along with researchers at Children’s Hospital Boston have developed a new “nanobiotechnology” that enables magnetic control of events at the cellular level. They describe the technology, which could lead to finely-tuned but noninvasive treatments for disease, in the January issue of Nature Nanotechnology.
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 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. This drags the cell’s receptors into large clusters, mimicking what happens when drugs or other molecules bind to them. This clustering, in turn, 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, says Ingber, the study’s senior investigator. More importantly, it represents the first time magnetism has been used to harness specific cellular signaling systems normally used by hormones or other natural molecules.
The beads provide the optimal crystal geometry to make them “superparamagnetic”–able to be magnetized and demagnetized over and over, notes Mannix, who shares first authorship of the paper with Sanjay Kumar, MD, PhD. 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.