Brown chemists create cancer-detecting nanoparticles

The illustration (top) shows how a RGD peptide-coated iron oxide nanoparticle binds with an integrin-rich tumor cell. At bottom left is a MRI of a mouse with the implanted U87MG... Click here for more information.

PROVIDENCE, R.I. [Brown University] — Magnetic resonance imaging (MRI) can be a doctor's best friend for detecting a tumor in the body without resorting to surgery. MRI scans use pulses of magnetic waves and gauge the return signals to identify different types of tissue in the body, distinguishing bone from muscle, fluids from solids, and so on.

Scientists have found that magnetic nanoparticles can be especially helpful in locating cancerous cell clusters during MRI scans. Like teeny guide missiles, the nanoparticles seek out tumor cells and attach themselves to them. Once the nanoparticles bind themselves to these cancer cells, the particles operate like radio transmitters, greatly aiding the MRI's detection capability.

Now, Brown University chemist Shouheng Sun and a team of researchers have created the smallest magnetic nanoparticles to date that can be employed on such seek-and-find missions. With a thinner coating, the particles also emit a stronger signal for the MRI to detect.

The results have been published online this week in the Journal of the American Chemical Society. Brown graduates students Jin Xie, Chenjie Xu and Sheng Peng collaborated on the research, along with Professor Xiaoyuan Chen and his associates from Stanford University.