The advent of colorectal cancer (CRC) screening, notably colonoscopy, has reduced deaths from this common and deadly malignancy by 30 percent. Unfortunately, colonoscopy misses about 24 percent of small and flat polyps, which often develop into aggressive forms of CRC.

Now Wellington Pham, PhD, and colleagues report that a novel fluorescent nanobeacon can discern normal from pathological tissues in freshly biopsied human colonic specimens obtained from Vanderbilt University Medical Center and a hospital in Osaka, Japan.

The topical nanobeacon consists of polystyrene nanoparticles with coumarin 6 dyes encapsulated in the core and coated with peanut agglutinin (PNA). PNA, in turn, has a high affinity for the Thomsen–Friedenreich (TF) antigen, which is expressed on cell surfaces and has a proven link to CRC.

Reporting in the International Journal of Nanomedicine, the researchers found that the nanobeacon emits a strong fluorescent signal suitable for tissue imaging and can discern adenoma and adenocarcinoma from normal tissues. Nearly all cases of CRC begin as benign adenomatous polyps.