Cell therapy is a technique whereby healthy normal cells or stem cells are infused into the body to treat disease.  In that cell therapy aims to replace damaged or diseased cells in the human body with normal cells or stem cells, it is necessary that scientists accurately target these therapeutic cells to diseased organs or tissues. In a discovery that may help speed use of cell therapy, French scientists reported their development of a way to deliver these therapeutic cells to diseased areas within the body using a simple magnetic effect.  Rawil Fakhrullin, from Ecole Normale Superieure (France), and colleagues have devised a process to make "stabilized" superparamagnetic iron oxide nanoparticles (SPIONs) in the laboratory, which are then attached to therapeutic cells. Their technique did not introduce toxicity, and enabled their delivery by a magnetic effect.  Observing that: “The magnetically responsive cells are viable and able to colonize and grow on substrates. Magnetically facilitated microorganization of functionalized cells into viable living clusters is demonstrated,” the study authors conclude that: “The technique described here may find a number of potential applications in cell-based therapies and in development of whole-cell biosensors.”