Gold-studded microcapsule could lead to targeted chemotherapy

In collaboration with the Press Association

Researchers in Germany have developed a tiny microcapsule studded with gold nanoparticles that can release substances inside a tumour cell when hit with a laser impulse.

Scientists at the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany, and Ludwig-Maximilian-University in Munich constructed microcapsules only a few thousandths of a millimetre in diameter.

The walls of the particles were made of alternating layers of positively and negatively charged polymers, allowing them to pass easily across a cells outer membrane.

The capsules were filled with a fluorescent marker dye, and were then studded with gold nanoparticles, before being exposed to cancer cells.

When bombarded with laser light, the gold particles heated up, splitting open the capsules? walls and releasing their contents inside the cells.

The method has so far only been used on isolated tumour cells but Professor Helmuth Mohwald, director of the Max Planck Institute of Colloids and Interfaces, said: "In principle, however, active substances could be released into the body this way." The next step is to find a way to target the microcapsules specifically to cancer cells.

"We have to add some kind of feature to the capsules so that they only recognise the target cells," said Professor Mohwld. Only these cells would then allow microcapsules through their membrane.

Cancer Research UK cautiously welcomed the development. "This is interesting work there are many laboratories around the world trying out all manner of high-tech methods to target drugs to cancer cells," said Henry Scowcroft, senior information officer at the charity.

"This laser-activated technology, as with all other potential targeting mechanisms, needs to be proven to be safe and reliable if it is ever to be used to beat cancer." The research was published in the journal Angewandte Chemie.