Squeezing life into patients
Engineers at Duke and Harvard universities have developed a “magnetic sponge” that after implantation into a patient can “squeeze” out drugs, cells, or other agents when passed over by a magnet. The researchers demonstrate that the new material — called a macroporous ferrogel — can be compressed as much as 70 percent by an applied magnetic field. The reversible compression quickly forces out the drugs, cells, or proteins embedded in the ferrogel. While porous biomaterials are used today as scaffolds for tissue regeneration and cell therapy, they are mostly passive in that the drug or cells usually diffuse or migrate out of the materials. The new scaffold the Duke and Harvard engineers have developed, on the other hand, can be controlled by external cues to release drugs and cells on command. The macroporous ferrogel contains magnetic iron nanoparticles, which respond to magnetic fields. Just as important, the researchers said, the new ferrogel has...