Doctors are not well armed in the fight against antibiotic-resitant bacteria. It is very difficult - or, in the worst case, impossible - to fight such infections. A team of researchers in Münster has now developed a unique nano-material that kills antibiotic-resitant bacteria. Researchers from Münster University and CeNTech (Center for NanoTechnology) were involved in the work, with Prof. Luisa De Cola leading the chemists and Prof. Berenike Maier heading the biologists. "Our results are a premiere. For the first time we have shown that it is possible to equip nano-particles with the following three functions: the particles adhere specifically to bacteria, mark them and then kill them off," says Dr. Cristian Strassert from the Physical Institute at WWU, who led the work on the study.
The starting material used by the researchers is so-called zeolite-L-nano-crystals. In a simple, inexpensive process these nano-particles are provided with a component which enables the particles to adhere to the surface of the bacteria. In addition, the particles are equipped with a colourant which glows green under a fluorescence microscope and makes the bacteria visible.
The effectiveness of the nano-particles is based on the "photodynamic therapy" method, whereby exposure to light sets off a reaction which kills the bacteria cells. The researchers also tack a third material on to the nano-crystals which is activated by red light and produces certain aggressive oxygen molecules. These oxygen molecules - "singlet oxygen" - start a chain reaction which destroys the bacteria cell.
The new nano-particles have hitherto adhered, through electrostatic interplay, to types of bacteria with certain surface properties ("gram-negativ"). The researchers are now working on making binding to other types of bacteria possible and increasing the binding specifity. In future the method could then be used to target certain bacteria in localised illnesses.
"Moreover," says Strassert, "we are looking at whether the method could be used not only to fight antibiotic-resitant bacteria, but also in the treatment of skin cancer." To this end the scientists want to get the nano-particles to bind specifically to cancer cells. "If that succeeds it would be conceivable for the nano-particles to be applied to the skin in future in a cream," says Strassert, describing his vision. "Through exposure to light the particles could then be activated and the cancer cells destroyed."