07 April 2008

Perfluorocarbon nanoparticles for the treatment and diagnosis of tumors

Scientists at the University of Washington, working under the leadership of Dr. Gregory M. Lanza and Professor Samuel A. Wickline, argue that the use of nanotechnology will significantly reduce the doses of toxic antitumor drugs used to treat malignant tumors, and, accordingly, reduce the severity of undesirable side effects.

The nanoparticles proposed by the authors, whose diameter is about 200 nm, consist of perfluorocarbon, a safe compound used in the manufacture of blood substitutes. The authors applied antibodies to the surface of nanoparticles that interact specifically with proteins mainly found on cells of growing blood vessels, and molecules of the powerful fungal toxin fumagillin.

Earlier clinical trials of fumagillin have shown that its combinations with other antitumor drugs effectively suppress tumor growth. But in doses effective with traditional methods of administration, fumagillin has a neurotoxic effect. The results obtained by the authors indicate that this can be avoided by using nanoparticles for drug delivery.

The accumulation of nanoparticles in the areas of active vascular formation and the release of fumagillin into the cells of the vascular wall blocks the growth of blood vessels, deprives the tumor of nutrients and significantly suppresses its growth.

Experiments on rabbits have shown that this approach, which provides targeted delivery of a chemotherapy drug to tumors, allows for a 1000-fold reduction in the effective dose of the toxin compared to traditional methods of its administration.

In an earlier work, the researchers demonstrated the possibility of applying a large range of different drugs to the surface of perfluorocarbon nanoparticles. To obtain evidence of the effectiveness of the method, they opted for fumagillin, but plan to continue experiments using other variants of nanoparticles. They have already shown that the use of particles coated with a contrast agent made it possible to obtain detailed maps of the growth of tumor vessels using conventional MRI equipment. To the surprise of the authors, it turned out that the vessels are concentrated in limited areas on the surface of one side of the tumor, and not diffusely throughout its entire volume.

Perfluorane nanocapsules can be used to solve various medical problems. In addition to targeted drug delivery, such nanoparticles can provide visualization of specific targets during magnetic resonance imaging (MRI), gamma tomography and ultrasound diagnostics.

The researchers believe that the new technology will increase the effectiveness of monitoring short- and long-term results of tumor treatment. It will allow you to adjust the duration of treatment, the dose of drugs or even the choice of a therapeutic protocol.

Preliminary clinical trials of nanoparticles, the purpose of which will be to select the optimal method for their use as imaging agents, are scheduled for this year. The results obtained will be used as a basis for the development of a new class of therapeutic agents.

The developed technology, owned by Barnes-Jewish Hospital and the University of Washington, is patented by Kereos, whose scientific co-founders are Gregory Lanza and Samuel Wickline.

Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of ScienceDaily


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