This is a standard response to a toxic substance and it suggests that the fish

This is a standard response to a toxic substance, and it suggests that the fish were trying to change the fullerenes into their constituent parts to get rid of them. However, she points out that despite the changes she found in their bodies, the fish appeared to be functioning normally. “They could eat just fine, and when I tried to catch them with a net, they were doing all the proper escape behaviours,” she says. “We think the damage was as debilitating as having a very bad migraine.”She says it is possible that the brain tissue might repair itself because there are cells in the brain that help the mending process, but the only way to find this out would be to carry out a follow-up study.In the fish livers, the buckyballs had switched on genes related to inflammation and involved in breaking down contaminants. This is quite new, and there is not a lot of hard data, according to Donaldson. He’s concerned about links that have been found between welding and Parkinson’s disease, because there is research showing that inhaled metals from welding-fume nanoparticles end up in the brain.In Oberdorster’s experiment, it seems that the buckyballs got into the fish brains by entering the bloodstream through the gills. “Inflammation in the lungs, unlike in the skin, for example, is not a trivial matter as it doesn’t take too much lung inflammation to compromise your breathing,” he says.Nanoparticles add another dimension because, being a similar size to viruses, they can get into the bloodstream through the lungs and can enter the brain directly via inhalation through the nose.

This immune response, Donaldson suggests, is to do with the large surface area of the lungs that is exposed. It may have evolved as a way to deal with invasion by bacteria. It could mean nothing or it could mean a lot,” he says.Donaldson’s interest in engineered nanoparticles comes by way of his work on asbestos, coal-mining dust and car pollution particles. It is well established that inhaling very small particles can cause inflammation in the lungs. “Attaching small molecules to the buckyball surface disrupts the electronic structure and therefore makes it less accommodating to extra electrons, so it doesn’t produce as many free radicals,” Kulinowski says.However, she warns against drawing any general conclusions about engineered nanoparticles. This work was published in the journal Bioconjugate Chemistry last summer.Encouragingly, both the Michigan and Rice groups have found that modifying the surface of these nanoparticles by attaching other molecules makes them far more body-friendly, and this may be a way to tune toxicity.

The team found that the size of the nanoparticle seemed to make a difference, with the smallest dendrimers having no adverse effects.A member of the team, Professor Mark Banaszak Holl, says that if the presence of nanoparticles can produce holes in cell membranes, it makes it easy for all sorts of molecules, including the nanoparticle itself, to get inside the cell. But we just don’t know,” says Ken Donaldson, Professor of Respiratory Toxicology at the University of Edinburgh “Some membranes have pores in them already. If you put therapeutic nanoparticles in the bloodstream and they started punching holes in the cells lining the blood vessels, it would seem to be a bad thing. We need to wait, she says, until scientists have properly investigated the relationship between structure and function for a wide range of nanoparticles.A great deal more work is also needed to see what happens inside the whole body, where cellular repair mechanisms, whole-organ and whole-body processes come into play “Every cell in the body is surrounded by a membrane.