- News Home
12 December 2013 1:00 pm ,
Vol. 342 ,
In an ambitious project to study 1000 years of sickness and health, researchers are excavating the graveyard of the now...
Stefan Behnisch has won awards for designing science labs and other buildings that are smart, sustainable, and...
The iconic 125-year-old Lick Observatory on Mount Hamilton near San Jose, California, is facing the threat of closure...
Recent results from the Curiosity Mars rover have helped scientists formulate a plan for the next phase of its mission...
A new, remarkably powerful drug that cripples the hepatitis C virus (HCV) came to market last week, but it sells for $...
In pretoothbrush populations, gumlines would often be marred by a thick, visible crust of calcium phosphate, food...
Evolutionary biologists have long studied how the Mexican tetra, a drab fish that lives in rivers and creeks but has...
Victorian astronomers spent countless hours laboriously charting the positions of stars in the sky. Such sky mapping,...
- 12 December 2013 1:00 pm , Vol. 342 , #6164
- About Us
14 May 1998 8:00 pm
A virus is like a smart bomb, its protein shell a warhead containing DNA or RNA that can subvert a cell's genetic machinery. Now researchers describe in today's issue of Nature how this vehicle might be put to peaceful use, delivering drugs into cells.
Trevor Douglas, a materials scientist at Temple University, spent many years assembling molecules that could be cradled inside ferritin, a protein that shuttles iron around the body. The problem with ferritin, he says, is that it only comes in one size. Then a few years ago, Douglas saw a cartoon of a hollow virus coat and realized that it could serve as a versatile container for molecules. With hundreds of known viruses, he says, "we have an entire library of shapes and sizes." Douglas teamed up with virologist Mark Young of Montana State University in Bozeman to tinker with making empty shells of the cowpea chlorotic mottle virus (CCMV).
CCMV, which normally mottles the leaves of cowpea plants, is a polyhedron, or many-sided ball. When the pH of a solution is higher than 6.5, the CCMV coat swells by 10%, opening up 60 holes about 2 nanometers in diameter. The researchers put empty virus heads, called virions, and particles of a well-known molecule called tungstate in a solution at above pH 6.5, and the tiny tungstate orbs flowed inside. After lowering the pH below 6.5, the holes in the virions closed, trapping tungstate inside. A researcher who wants to use the virus head to transport a drug could tailor the virion to meet the molecule's needs, Douglas says.
Using virions for drug delivery "is a neat concept," says Paul Robbins, a molecular geneticist at the University of Pittsburgh Medical School. However, he points out, several hurdles remain--including how to work with viruses that don't swell and contract in changing pH, and how to trick the immune system to not attack virions. "The work is pretty much a proof of concept at this point," Douglas says.