Nanoparticles for Anticancer Drug Delivery

Two recent studies have described the use of nanoparticles to deliver chemotherapeutic drugs for the treatment of cancer.

Investigators at the University of Pennsylvania (Philadelphia, USA ) used polymersomes (artificial cells with degradable membranes made of polyethylene glycol polyester) as a means to deliver the anticancer drugs paclitaxel and doxorubicin. Writing in the March 18, 2006, online edition of Molecular Pharamaceutics, they explained that when the polymer and the two drugs were mixed in an aqueous solution, polymersomes were generated that contained the water-insoluble paclitaxel embedded within the polyester shell, while doxorubicin, which is water-soluble, remained within the interior of the polymersome.

"The system provides a number of advantages over other Trojan horse-style drug delivery system, and should prove a useful tool in fighting a number of diseases,” said Dr. Dennis Discher, professor of engineering and applied science at the University of Pennsylvania. "Here we show that drug-delivering polymersomes will break down in the acidic environment of the cancer cells, allowing us to target these drugs within tumor cells.”

Investigators at the Massachusetts Institute of Technology (Boston, USA) also used a polyethylene glycol polymer to manufacture nanoparticles to transport the chemotherapeutic drug docetaxel into prostate cancer cells. The nanoparticles were targeted specifically for the tumor cells by incorporating RNA aptamers that recognize the extracellular domain of the prostate-specific membrane antigen (PSMA), a well-characterized antigen expressed on the surface of prostate cancer cells.

The nanoparticles were used to treat a group of mice that had been infected with human prostate cancers. Results published in the April 10, 2006, online edition of the Proceedings of the [U.S.] National Academy of Sciences revealed that a single injection of the nanoparticles completely eradicated the tumors in five of the seven treated animals, and the remaining animals also had significant tumor reduction, compared to the controls.



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University of Pennsylvania
Massachusetts Institute of Technology