Achieving the desired effect is often only a question of the right place and the right moment - and this also applies to drugs. In order to be transported in the bloodstream, they need to be water-soluble.

Nanoparticles covered in brushes: controlled by temperature and salt content, the polymer chains enable the gold particles to move back and forth between an aqueous solution and an oil.

However, in order to get past cell membranes, they have to be fat-soluble. Scientists at the Max Planck Institute of Colloids and Interfaces have now developed a method with which they can channel nanoparticles originating from gold atoms from a water solution into an oil.

The water and oil system serves as a model for the boundary between the bloodstream and tissue. The researchers are able to overcome this boundary in a targeted manner, as they are able to coat the particles with a polymer whose solubility they can influence.

(Angewandte Chemie Online, November 2007)