Investigators at the School of Medicine have shown that engineered nanoparticles can be safely administered in a mouse study. Their finding, published April 20 in Science Translational Magazine, could bring about human trials that utilize the nanoparticles in the detection of colorectal and other cancers.

Nanoparticles are gold-centered balls that are tinier than viruses, measuring 100 nanometers in diameter. The materials that coat the gold centers have subtle optical properties, and the centers themselves are roughed up for detection by Raman microscopes.

“Photoimaging with these nanoparticles holds the promise of very early disease detection, even before any gross anatomical changes show up, without physically removing any tissue from the patient,” Sanjiv Sam Gambhir, a senior author of the study, said in a press release.

But before the nanoparticles can be used in human beings, scientists had to first prove that they are not harmful. The Stanford study was, in fact, the first to prove the safety of these nanoparticles.

To demonstrate this, scientists administered the nanoparticles to two groups of mice, each including 30 male and 30 female animals. The first group received the nanoparticles rectally and the second group received the treatment intravenously. In both cases, the investigators did not find signs of toxicity.

This good news may mean that similar intravenous treatments could be applied to human beings in the diagnosis of colorectal cancer. Gambhir and his colleagues are in the process of filing for Food and Drug Administration (FDA) approval to move to clinical trials.

The University’s Department of Radiology, the National Cancer Institute and the Canary Foundation sponsored the recent nanoparticles study.

–An Le Nguyen