PROVIDENCE, R.I. [Brown University] Hepatocellular carcinoma is the most common cancer to strike the liver. More than 500,000 people worldwide, concentrated in sub-Saharan Africa and Southeast Asia, are diagnosed with it yearly. Most of those afflicted die within six months.
A big obstacle to treatment of liver cancer is the lack of early diagnosis. Current techniques, including ultrasound, CT and MRI scans, spot tumors only when they have grown to about 5 centimeters in diameter. By that time, the cancer is especially aggressive, resisting chemotherapy and difficult to remove surgically.
Now a research team led by Brown University reports some promising results for earlier diagnosis. In lab tests, the team used gold nanoparticles ringed by a charged polymer coating and an X-ray scatter imaging technique to spot tumor-like masses as small as 5 millimeters. The approach, detailed in the American Chemical Society journal Nano Letters, marks the first time that metal nanoparticles have been used as agents to enhance X-ray scattering signals to image tumor-like masses.
"What we're doing is not a screening method," said Christoph Rose-Petruck, professor of chemistry at Brown University and corresponding author on the paper. "But in a routine exam, with people who have risk factors, such as certain types of hepatitis, we can use this technique to see a tumor that is just a few millimeters in diameter, which, in terms of size, is a factor of 10 smaller."
The team took gold nanoparticles of 10 and 50 nanometers in diameter and ringed them with a pair of 1-nanometer polyelectrolyte coatings. The coating gave the nanoparticles a charge, which increased the chances that they would be engulfed by the cancerous cells. Once engulfed, the team used X-ray scatter imaging to detect the gold nanoparticles within the malignant cells. In lab tests, the nontoxic gold nanoparticles made up just 0.0006 percent of the cell's volume, yet
|Contact: Richard Lewis|