Innovation

Glowing Dye: Stanford Researchers Develop Fluorescent Dye To Help Doctors Identify Tumors, Cancer Inside Your Body

Fluorescent Dye
Stanford University researchers have developed a fluorescent dye to help better identify cancers and tumors inside the body. Stanford University

Fluorescent dye can help doctors identify different cancer and tumors just beneath patient's skin. However, many of the dyes available take time to leave the body and may be potentially harmful — or at least it did before researchers from Stanford University conducted a study to solve these problems. Their findings are available now in Nature Materials.

"The difficulty is how to make a dye that is both fluorescent in the infrared and water soluble," first author Alex Antaris, a graduate student at Stanford, said in a press release. "A lot of dyes can glow but are not dissolvable in water, so we can't have them flowing in human blood. Making a dye that is both is really the difficulty. We struggled for about three years or so and finally we succeeded."

When the fluorescent dye enters the bloodstream, doctors use a near-infrared (NIR-II) imaging to "probe at centimeter depths, which is sufficient for a whole range of skin, thyroid, and head and neck cancers," Antaris told Medical Daily in an email. The particles within the Stanford team's dye emit light within a certain wavelength, thus making them visible to NIR-II imaging — longer than those emitted by particles found in previous dyes. The long wavelengths allow for better picture quality, even through layers of skin and tissue. The dye makes images so accurate that it "can allow surgeons to perform image-guided surgery that lets them see the glowing tumor while the background tissue is dark," Antaris said.

"This allows for a more complete and precise removal of tumors. With only cancerous tissue glowing, doctors can cut out tumors without missing cancer cells or excessively cutting out healthy tissue," he added.

The researchers' dye is incredibly different from the contrast dye used in CT scans to highlight specific organs, tissues. or blood vessels in the body so its easier to spot. While an impressive imaging modality, Antaris said, it's not without its drawbacks.

"For instance, CT scans employ ionizing radiation, which is a safety concern, the CT setups are relatively expensive compared to fluorescence imaging setups, and they have inferior time and spatial resolution compared to NIR-II imaging," he said. The Stanford dye's ability to be captured in real time can help identify tumors and cancers in seconds compared to minutes CT scans require.

As important as this real-time capturing is, the real achievement of the fluorescent dye is how quickly it can be excreted from the body. "The exciting aspect of our dye is that it emits in the NIR-II, yet has all the excretion properties of FDA-approved optical contrast agents," Antaris said.

He continued: "Previous nanomaterial contrast agents emitted in the NIR-II, yet were trapped in the liver and spleen and excreted slowly. It is very exciting that we have found a class of materials that have NIR-II optical properties as well as good excretion."

Outside of detecting cancers and tumors, Antaris says the dye can be used to detect lymph nodes in a specific area for removal, allowing surgeons to accurately connect small blood vessels to grafted tissues during reconstructive surgery. This would produce clear images of blood vessels in the eye, which could greatly advance our knowledge (and potential treatment of) certain eye diseases.

Source: Antaris A, et al. A small-molecule dye for NIR-II imaging. Nature Materials. 2015.

Loading...