Nanoparticle 'smart bomb' targets drug delivery to cancer cells

February 12, 2009

Researchers at North Carolina State University have successfully modified a common plant virus to deliver drugs only to specific cells inside the human body, without affecting surrounding tissue. These tiny "smart bombs" - each one thousands of times smaller than the width of a human hair - could lead to more effective chemotherapy treatments with greatly reduced, or even eliminated, side effects.

Drs. Stefan Franzen, professor of chemistry, and Steven Lommel, professor of plant pathology and genetics, collaborated on the project, utilizing the special properties of a fairly common and non-toxic plant virus as a means to convey drugs to the target cells.

The researchers say that the virus is appealing in both its ability to survive outside of a plant host and its built-in "cargo space" of 17 nanometers, which can be used to carry chemotherapy drugs directly to tumor cells. The researchers deploy the virus by attaching small proteins, called signal peptides, to its exterior that cause the virus to "seek out" particular cells, such as cancer cells. Those same signal peptides serve as "passwords" that allow the virus to enter the cancer cell, where it releases its cargo.

"We had tried a number of different nanoparticles as cell-targeting vectors," Franzen says. "The plant virus is superior in terms of stability, ease of manufacture, ability to target cells and ability to carry therapeutic cargo."

Calcium is the key to keeping the virus' cargo enclosed. When the virus is in the bloodstream, calcium is also abundant. Inside individual cells, however, calcium levels are much lower, which allows the virus to open, delivering the cancer drugs only to the targeted cells.

"Another factor that makes the virus unique is the toughness of its shell," Lommel says. "When the virus is in a closed state, nothing will leak out of the interior, and when it does open,
it opens slowly, which means that the virus has time to enter the cell nucleus before deploying its cargo, which increases the drug's efficacy."

The researchers believe that their method will alleviate the side effects of common chemotherapy treatments, while maximizing the effectiveness of the treatment.

Source: North Carolina State University

Explore further: Biologist investigates how gene-swapping bacteria evade antibiotics

Related Stories

Olympic teams to swim, boat in Rio's filth

July 30, 2015

Athletes competing in next year's Summer Olympics here will be swimming and boating in waters so contaminated with human feces that they risk becoming violently ill and unable to compete in the games, an Associated Press ...

New defense mechanism against viruses discovered

September 11, 2014

Researchers have discovered that a known quality control mechanism in human, animal and plant cells is active against viruses. They think it might represent one of the oldest defense mechanisms against viruses in evolutionary ...

Virus rounds up enzymes, disarms plant

June 2, 2014

University of Tokyo researchers have described how a plant-virus protein suppresses an important plant defense mechanism that remembers viral genetic information, providing a new target for developing the first-ever chemical ...

Recommended for you

Gold nanomembranes resist bending in new experiment

October 9, 2015

The first direct measurement of resistance to bending in a nanoscale membrane has been made by scientists from the University of Chicago, Peking University, the Weizmann Institute of Science and the Department of Energy's ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Feb 12, 2009
Just COOL those cells and you will not have to KILL them. Their mitosis rate will slow and the mitochondria will regain control! You will be right back in there killing more cells next year!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.