Study Examines Drug Delivery With Liposomes
Several chemotherapy drugs can only be given at certain doses because they're highly toxic to healthy cells, and at those doses, the concentration of the drug that reaches cells in the tumor may be quite low.
Scientists have been investigating the use of liposomes, hollow spheres of fat molecules, to deliver chemotherapy drugs directly to tumors. These liposomes melt and release their contents when exposed to heat.
In a new study, Ana M. Ponce and Mark W. Dewhirst, D.V.M., Ph.D., of Duke University Medical Center, and colleagues injected doxorubicin-containing liposomes into rats bearing fibrosarcomas. The researchers monitored the rats continuously using magnetic resonance imaging to watch how the liposomes distributed in the body. They also tracked whether it was most effective to inject the liposomes before, during, or before and during heating of the tumor, which triggers the liposomes to dissolve and release the doxorubicin inside.
Based on their results, the researchers conclude that the drug distribution was most effective when the liposomes were given while the tumor was being heated.