This is the conclusion reached by american researchers following tests on chickens and human cell cultures. Michael L. Shuler of cornell university in ithaca (new york state, u.S.) and colleagues hope to use this model to study the effects of various nanoparticles.
Tiny nanoparticles of various origins are already used in numerous materials. There are no clear results yet on the risks and side effects of this technology. Shuler’s team reports on the experiments in the journal "nature nanotechnology".
Nanoparticles are up to 100 nanometers in size and have different source materials. One nanometer corresponds to one millionth of a millimeter. The dwarf particles have a comparatively coarse surface in relation to their volume and can change the properties of materials. Nanoparticles are used in medicine, personal care products and as protective coatings.
The team used special 50-nanometer particles of polystyrene for its experiments. This plastic is used, for example, in food packaging. According to the authors, the substance is considered non-toxic to the body.
The researchers tested the particles on cultures of human cells lining the intestine. A high dose of nanoparticles was reported to increase iron transport in cell cultures by affecting the cell membrane. Chickens showed differences in iron uptake depending on whether they were fed nanoparticles over several weeks (chronic) or given them directly into the small intestine once (acute).
During acute administration, iron absorption by the intestine was lower than in chickens that had not received nanoparticles or had received them for several weeks. Those birds that ingested polystyrene particles over a long period of time had changes in the intestinal mucosa. The authors write that the surface for the potential absorption of iron in the intestine had become coarsened.
Researchers stress, however, that further studies are needed to draw conclusions about the effects of nanoparticles.