10.04.2007
In this study, the research team used skinny cylindrical nanoparticles
composed of synthetic polymers to deliver the anticancer drug paclitaxel to a
human lung tumor tissue implanted in mice. Because the cylinders remained in
circulation for up to one week after injection, they also delivered a more
effective dose, killing more cancer cells and shrinking the tumors to a much
greater extent.
Spherical nanoparticles typically only stay in circulation for a few hours.
This discovery is also helping scientists understand why some viruses, such as
cylinder-shaped viruses like Ebola and H5N1 influenza, are so effective.
This study appeared online in Nature Nanotechnology in advance of print
publication in March 2007.
Researchers at the University of Pennsylvania School of Medicine & School of
Engineering and Applied Science have discovered a better way to deliver drugs
to tumors. By using a cylindrical-shaped carrier they were able sustain
delivery of the anticancer drug paclitaxel to an animal model of lung cancer
ten times longer than that delivered on spherical-shaped carriers. These
findings have implications for drug delivery as well as for better
understanding cylinder-shaped viruses like Ebola and H5N1 influenza.
This study appeared online in Nature Nanotechnology in advance of print
publication in March 2007.
“These are particles that go with the flow,” says Dennis E. Discher, PhD,
Professor of Chemical and Biomolecular Engineering at Penn’s Institute for
Medicine and Engineering. “The blood stream is constantly pumping, and these
cylindrical nanoparticles align with the flow and persist in circulation
considerably longer than any known spherical particles.”
In this study, the research team used skinny cylindrical nanoparticles
composed of synthetic polymers to deliver the anticancer drug paclitaxel to a
human lung tumor tissue implanted in mice. The cylinders have diameters as
small as 20 nm and lengths approaching the size of blood cells. The paclitaxel
shrunk the tumors and, because the cylinders remained in circulation for up to
one week after injection, they delivered a more effective dose, killing more
cancer cells and shrinking the tumors to a much greater extent. Spherical
nanoparticles typically only stay in circulation for a few hours.
The research team used nanoparticles that contained one water-loving chain of
a common polymer called polyethyleneglycol (PEG). PEGs are commonly found in
everyday items like shampoo and some foods. Although synthetic, PEGs have
already been approved as biocompatible to humans, making them ideal carriers,
note the researchers.
While these findings could impact the way lung cancer is treated, this
discovery of how to more effectively deliver drugs to the body could also
improve the treatment of such other illnesses as cardiovascular disease as
well as other types of cancers.
This discovery is also helping scientists understand why some viruses are so
effective. “Cylindrical delivery systems exist in nature, with two prime
examples being the Ebola virus and the H5N1 Influenza virus,” says Discher.
“These findings can help us understand how this shape evolved in nature and
the advantages of using it for treating people.”
In addition to Discher, Yan Geng, Paul Dalhaimer, Shenshen Cai, Richard Tsai,
and Manorama Tewari, all of Penn, and Tamara Minko of Rutgers University, are
co-authors. The National Institute of Biomedical Imaging and BioEngineering
provided funding for this research.
Karen Kreeger | Quelle: EurekAlert!
Weitere Informationen:
www.uphs.upenn.edu