12 | NewScientist | 14 April 2012

DRUG-SMUGGLING nanoparticles could be the latest recruits in the fight against cancer. The first results from early-stage trials show that cancer drugs couriered by nanoparticles may reduce the size of tumours in humans.

Researchers from BIND Biosciences in Boston filled nanoparticles with the cancer drug docetaxel and injected them into the blood of 17 people who

had cancers that are normally resistant to the drug. Forty-two days later, two of the volunteers’ tumours had shrunk in size significantly, and the rest of the volunteers’ tumours had not grown (Science Translational Medicine, DOI: 10.1126/scitranslmed.3003651).

When injected into the body, docetaxel doesn’t discriminate between healthy and cancerous

Lighting cancer speeds diagnosis

INFRARED light can help spot cancerous tissue in an instant.

To look for cancer in a biopsy, the sample is stained to highlight DNA and a protein in cytoplasm. Cancer cells contain a higher ratio of DNA to protein and a larger nucleus, making it possible to judge whether cancer is present.

To make things more objective, Chris Phillips and his colleagues at Imperial College London used light. The chemical bonds in each molecule absorb infrared light of a characteristic wavelength. By measuring the level of absorption, the amount of DNA and protein in a sample can be calculated.

The team used the method to measure levels of the two types of molecule, then generated an image to highlight areas with a cancer-like ratio (Optics Express, DOI: 10.1364/oe.20.007290).

“You put in the tissue and you can get an image in 10 to 20 seconds,” says Phillips.

Social ants have deadly skin fungus licked

IF ONE of your neighbours had a life-threatening skin disease, your first response probably wouldn’t be to lick them. That’s because you are not a social insect. Ants in a colony lick their infected nest-mates, and doing so seems to inoculate them against future infection, protecting the colony.

Sylvia Cremer at the Institute of Science and Technology Austria in Klosterneuburg and colleagues exposed ants (Lasius neglectus) to an infectious fungus called Metarhizium anisopliae. The team then housed each infected ant with five uninfected

Mat

thia

s Ko

nr

ad,

ist

aust

ria

in BriEF

Nano-couriers deliver targeted chemo cells. However, the nanoparticles only released their payload when they reacted with molecules on the tumour’s surface, so up to 80 per cent less of the drug needed to be injected to get the same amount into the tumour.

As a result, physicians should be able to up the concentration of the drug without worrying about toxic side effects, says Jeffrey Hrkach, senior vice-president at BIND. He says larger clinical trials are in the pipeline.

fellows and watched what happened next.The healthy ants groomed their infected nest-mates,

licking the fungus off them (shown above). As a result they picked up slight infections themselves, although not enough to kill them. Afterwards, two immune-system genes specifically used to fight fungi became activated in the healthy nest-mates, which were then more able to beat the fungus. These effects were not seen in ants that could not touch their infected nest-mates, so the changes were not due to a social signal, such as a pheromone (PLoS Biology, DOI: 10.1371/journal.pbio.1001300).

Cremer thinks the ants were inoculating themselves against the fungal disease, just as humans once inoculated themselves with low levels of smallpox to prepare themselves for full-scale infections.

PLANETS and moons weren’t the only cosmic objects to get splattered with gold early on in the solar system’s history – small asteroids got some bling too.

Gold, platinum and other iron-loving, or “siderophile”, elements get dragged to the core of a planet if they are present when it is still forming. So siderophiles found in planets’ mantles must have been delivered later, by meteorites.

Now Christopher Dale of the University of Durham, UK, and colleagues have shown that smaller bodies like the asteroid Vesta also have siderophiles in their mantles. That suggests these bodies, which formed earlier than planets, also received gold from meteorites (Science, DOI: 10.1126/science.1214967).

How asteroids got their bling

120414_N_InBrief.indd 12 5/4/12 17:30:54