doi:10.1038/nindia.2013.164 Published online 10 December 2013
Researchers have produced polysaccharide-modified superparamagnetic iron oxide nanoparticles that can be used as a contrast agent in magnetic resonance imaging (MRI) . They used these nanoparticles to image diseased livers in rats, indicating their potential to be used in the diagnosis of liver diseases.
Alcoholism can lead to liver disorders, such as fibrosis and cirrhosis, which can be cured if diagnosed early. Diseased liver cells express specific protein receptors, which have an affinity for carbohydrate polymers. Previous studies have shown that carbohydrate-modified magnetic nanoparticles can be used as a contrast agent for imaging malfunctioning livers. However, nanoparticles modified by low-molecular-weight dextran were found to cause renal failure.
To overcome this problem, the researchers modified superparamagnetic iron oxide nanoparticles with high-molecular-weight dextran. They then used human red and white blood cells, platelets and liver cancer cells to assess the blood compatibility and toxicity of the modified nanoparticles. They also used the nanoparticles as a contrast agent for imaging fibrosis-induced damage in rat liver.
The blood compatibility tests revealed that the modified nanoparticles had no harmful effects on human red blood cells in the concentration range used in the study. About eighty per cent of the liver cancer cells survived when exposed to the modified nanoparticles, indicating that these particles are nontoxic. In addition, the nanoparticles did not aggregate on human white blood cells and platelets.
The study found enhanced uptake of the nanoparticles in rat liver. The small size of the nanoparticles increased their permeability and retention in fibrosed liver. Damaged areas of the liver were well differentiated in the contrast images as hyperintense streaks.
"The developed nanomaterials selectively targeted diseased liver for imaging, sparing other healthy organs," says R. S. Jayasree, a senior author of the study.