Tiny Smart Bombs Deliver Chemo Drug to Cancer
Cells with Fewer Side Effects
They are a modified plant virus one thousands of
times smaller than the width of a human hair
Feb. 13, 2009 A more effective chemotherapy
treatment with few or no side effects, a dream for many senior citizens
battling cancer, may be on the way in the form of tiny smart bombs
that carry their payload right to the targeted cancer cells.
Couples encouraged to examine each other for
suspicious moles that could be skin cancer. Researchers estimate that 40
50% of people in the U.S. who live to age 65 will have nonmelanoma
skin cancer at least once.
Sarcosine is better indicator of advancing disease
than traditional prostate specific antigen test (PSA); it is detected in
urine, researchers hopeful simple urine test can be used
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 "smart bombs" are one thousands of times smaller than the
width of a human hair.
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.
Keep up with the latest news for senior citizens, baby
boomers
Feb. 13, 2009 A more effective chemotherapy
treatment with few or no side effects, a dream for many senior citizens
battling cancer, may be on the way in the form of tiny smart bombs
that carry their payload right to the targeted cancer cells.
