Nanorods Tag Tumors For Surgery

Doctors in the future might be able to detect early-stage ovarian cancer with the help of rod-shaped gold nanoparticles, according to a study reported in ACS Nano (DOI: 10.1021/nn304347g). After injecting mice with the nanorods, researchers from Stanford University used a combination of photoacoustic imaging and surface-enhanced Raman spectroscopy (SERS) to image various types of ovarian tumors in the rodents and visualize them during surgery. Three hours after the injection, the team, led by Sanjiv S. (Sam) Gambhir, observed a peak photoacoustic signal from tumors in the mice that absorbed the nano­rods. Then, during surgery, the researchers used SERS imaging to identify the boundaries of those tumors and ensure complete removal of the troublesome tissue. The SERS signal comes from a near-infrared dye bound to the outsides of the nanorods. This is the first time a combination of photo­acoustic and SERS imaging has been used to find ovarian tumors in living mice, the researchers say. These two techniques complement one another because the former deeply penetrates tissue and the latter can sensitively detect molecular tags.