The advance could help diagnose irritable bowel syndrome, celiac disease, Crohn's disease and other gastrointestinal ailments.
Located deep in the human gut, the small intestine is not easy to examine. X-rays, MRIs and ultrasound images provide snapshots but each suffers limitations.
Researchers at the University at Buffalo are developing a new imaging technique involving nanoparticles suspended in liquid to form "nanojuice" that patients would drink.
Upon reaching the small intestine, doctors would strike the nanoparticles with a harmless laser light, providing an unparallelled, non-invasive, real-time view of the organ.
"Conventional imaging methods show the organ and blockages, but this method allows you to see how the small intestine operates in real time," said corresponding author Jonathan Lovell.
"Better imaging will improve our understanding of these diseases and allow doctors to more effectively care for people suffering from them," said Lovell.
Sandwiched between the stomach and large intestine, the small intestine is where much of the digestion and absorption of food takes place.
To assess the organ, doctors typically require patients to drink a thick, chalky liquid called barium.
Doctors then use X-rays, magnetic resonance imaging and ultrasounds to assess the organ, but these techniques are limited with respect to safety, accessibility and lack of adequate contrast, respectively.
Lovell and a team of researchers worked with a family of dyes called naphthalcyanines. These small molecules absorb large portions of light in the near-infrared spectrum, which is the ideal range for biological contrast agents.
They are unsuitable for the human body, however, because they don't disperse in liquid and they can be absorbed from the intestine into the blood stream.
To address these problems, the researchers formed nanoparticles called "nanonaps" that contain the colourful dye molecules and added the abilities to disperse in liquid and move safely through the intestine.
In laboratory experiments performed with mice, the researchers administered the nanojuice orally. They then used photoacoustic tomography (PAT), which is pulsed laser lights that generate pressure waves that, when measured, provide a real-time and more nuanced view of the small intestine.
The research was published in the journal Nature Nanotechnology.