Posted: January 22, 2007

Chitosan nanoparticles suppress liver cancer growth

(Nanowerk News) Nanoparticles made of chitosan, a naturally occuring polymer isolated from crab and shrimp shells, have shown promise as carriers of anticancer drugs, antitumor genes, and other novel therapeutic agents. In addition, chitosan nanoparticles by themselves appear toxic to various types of malignant cells. To better understand this latter observation, Lifeng Qi, Ph.D., at West Virginia University, working with colleagues at Zhejiang University in Hangzhou, China, has conducted a detailed study evaluating the effect of chitosan nanoparticles on human liver cancer cells.
The investigators, who published the results of these studies in the European Journal of Cancer ("In vitro and in vivo suppression of hepatocellular carcinoma growth by chitosan nanoparticles"), prepared chitosan nanoparticles with an average diameter of 40 nanometers and added various concentrations of these nanoparticles to human liver cancer cells growing in culture. The researchers also administered chitosan nanoparticles orally to mice bearing human liver tumors.
From these studies, the researchers found that chitosan nanoparticles are capable of changing the composition of the cell membrane of malignant cells. The investigators found that chitosan nanoparticles also neutralized the surface charge of human liver tumor cells and altered the charge of the membrane surrounding the cells’ mitochondria. The researchers noted that lipid metabolism increased in the membranes of cells treated with these nanoparticles. The effect of these changes in tumor cell membranes appears to retard the growth of tumors growing in mice by as much as 60 percent. The fact that these nanoparticles were delivered orally bodes well for future studies aimed at using chitosan nanoparticles to deliver anticancer agents to tumors.
Source: National Cancer Institute