Research Highlights

Photoacoustic Tomography Can Safely Examine the Gut using Frozen Nanonaps

2015-07-24 592

Professor Chulhong Kim

Using POSTECH Professor Chulhong Kim’s custom-built high-resolution photoacoustic imager, researchers were able to examine the combination of nanonaps and photoacoustic tomography illuminated inside the intestine of a mouse. (Credit: Chulhong Kim)
Millions of people worldwide who suffer from digestive diseases may soon have a safer alternative to traditional radiological techniques when visiting the hospital for imaging of the gastrointestinal tract.
Researchers from the Pohang University of Science and Technology (POSTECH), the University at Buffalo, and University of Wisconsin–Madison have discovered a new and safer way of making intestinal imaging non-invasive for patients.
Their new method of imaging, photoacoustic tomography (PAT), would use nanoparticles that can withstand the harsh conditions of the stomach and intestine, avoid systemic absorption, and provide good optical contrast. The development is described in the journal Nature Nanotechnology. POSTECH Professor Chulhong Kim of the Department of Creative IT Engineering (CiTE) was a corresponding author of the study.

images of system and intestine

Ultrasound, X-ray, computer tomography (CT) scan, and magnetic resonance imaging (MRI) are currently the most commonly used for diagnosing gastrointestinal conditions, but are often expensive and can be unsafe with repeated use. The small intestine is about 20 feet long which makes it difficult for doctors to pinpoint gastrointestinal diseases.
“Because of these challenges, our new imaging technique, PAT, will lead to a safer and non-invasive way to diagnose and treat gut diseases,” said Professor Kim.
The researchers’ new method will allow doctors to see how the small intestine operates in real-time as opposed to conventional instruments that only show images of the organ and blockages. They worked with dyes called naphthalcyanines encased in nanoparticles that move safely inside the digestive system without being absorbed into the blood.
Patients would be able to drink the concoction which would provide doctors with a noninvasive, real-time view of the small intestine with the use of a safe pulsed laser light, also known as PAT. For the experiment, the researchers orally administered the frozen nanonaps on mice and used PAT. The instrumentation cost of PAT is low and it is safe, non-invasive, and non-ionizing making it an attractive alternative to existing instruments.

The research was supported by grants from the Korean Ministry of Science, ICT and Future Planning (the IT Creative Consilience Program at CiTE and the Engineering Research Center at the Department of Mechanical Engineering at POSTECH), the National Institutes of Health, and the Department of Defense.