Medicines are most helpful when they directly affect the diseased organs or cells - for example, tumour cells. Scientists at the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany, and Ludwig-Maximilian-University in Munich, have come one step closer to that goal: they have intentionally released a substance in a tumour cell. The scientists placed the substance in a tiny capsule which gets channelled into cancer cells, and is then "unpacked" with a laser impulse. The laser light cracks its polymer shell by heating it up and the capsule'^TMs contents are released. (Angewandte Chemie, July 2006).

Treating malignant tumours is difficult. Doctors have to destroy the tumour, but healthy tissue needs to be preserved. Chemotherapy tends to kill diseased cells, at the same time causing great damage to the body in general. So scientists are looking for ways to destroy only the rampant tumour cells. One way to achieve this is to transport substances inside of microcapsules into the tumour cells and release them there. Researchers led by Andre Skirtach and Gleb Sukhorukov at the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany, along with Wolfgang Parak at Ludwig-Maximilian-University in Munich, have now used a laser as a means of opening microcapsules inserted into a tumour cell. The capsules subsequently release their contents, a fluorescent test substance, into the cell. The scientists used a light microscope to monitor how the luminous materials distribute themselves within the cell.

The vehicle that the researchers used was a polymer capsule only a few micrometres in diameter. The walls of the capsules were built from a number of layers of charged polymers, alternating positive and negative. In the laboratory, at least, this is an established way of producing transport containers for medicines, cosmetics, or nutrients, which can also pass through cell membranes. Andre Skirtach and his colleagues equippe
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Contact: Dr. Andre Skirtach
skirtach@mpikg.mpg.de
0049-331-567-9235
Max-Planck-Gesellschaft
23-Aug-2006