Nanoparticles Deliver Targeted Micro-Doses of Toxic Drugs

Cancer researchers have described a technique for the guided delivery of very small doses of chemotherapeutic drugs that would otherwise be too toxic to use.

Investigators at Washington University School of Medicine (St. Louis, MO, USA) worked with the drug fumagillin, which is produced by the fungus Aspergillus fumigatus that block blood vessel formation by binding to the enzyme methionine aminopeptidase. Unfortunately, while fumagillin suppressed angiogenesis in cancer models and clinical trials, it was found to be a neurotoxin at systemic doses.

In the current study, the investigators incorporated very small doses of fumagillin into perfluorocarbon nanoparticles. The nanoparticles were coated with proteins to target them specifically to the blood vessel producing region of tumor growth.

Details published in the March 24, 2008, online edition of The FASEB Journal described how tumor-bearing rabbits were treated on days six, nine, and 12 post-implantation with targeted fumagillin nanoparticles (30 µg/kg), targeted nanoparticles without drug, nontargeted fumagillin nanoparticles (30 µg/kg) or saline. Furthermore, the investigators described the use of their nanoparticles in conjunction with MRI imaging to monitor tumor growth and morphology.

Results of the study revealed that tumor volume was reduced among rabbits receiving targeted fumagillin nanoparticles compared with the three control groups. MRI scans showed that blood vessel formation tended to concentrate in limited areas on the surface at one side of tumors instead of dispersing uniformly.

"What this report clearly demonstrates is that our nanoparticles can carry chemotherapeutic drugs specifically to tumors and have an effect at the tumor site,” said senior author Dr. George Lanza, associate professor of medicine and biomedical engineering at Washington University School of Medicine. "Sometimes when I give presentations about our nanotechnology, people react as if it was science fiction or at best a technology of the distant future. But we have shown that the technology is ready for medical applications now.”


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