Bacteria killers from the nano factory

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Though we cannot see them with the naked eye, bacteria are everywhere – on door handles in the office, on dumbbells in the gym and in our coffee machines. Most are harmless, but bacteria can pose a serious threat if they contaminate catheters or implants in a hospital. According to a recent study conducted by the European Centre for Disease Prevention and Control (ECDC)around 2.6 million Europeans each year become infected by germs which they pick up in a hospital. Roughly 91,000 patients die as a result.

Bacteria form tenacious colonies

Bacteria like to form colonies on door handles

Individual free-floating pathogen cells in air or water are easy to combat and as such are relatively harmless. But when they form colonies, known as biofilms, they are almost impossible to control. Using these slime-forming tissue-like microstructures of pores and channels, bacteria can attach themselves to surfaces and multiply. Although millions of years old, biofilms are a microorganism life form that has only been studied for a few decades. And they are difficult to crack.

Biology and materials science – a powerful team

The chemist Professor Sebastian Polarz and the microbiologist Dr David Schleheck from the University of Konstanz think they may have found a suitable weapon. Their idea is to attach "miniature factories" to the surfaces to produce antibacterial substances. The two Konstanz-based researchers are the perfect team: Polarz is a materials scientist who develops novel silicate materials on a nano scale. Thanks to their innumerable tiny pores, they have a very large surface area which his colleague furnishes with highly reactive chemical and biochemical compounds. These attack the biofilm structures and also kill the bacteria they contain. "We are working on two levels", explains Schleheck. "For one thing, we want to prevent bacteria from attaching themselves to and growing on surfaces in the first place. And for another, we hope the nano machines will be able to remove already established biofilms."

Prize for innovative research

At the end of 2016, Polarz and Schleheck were awarded the research prize of the Dr. Karl Helmut Eberle-Stiftung for their idea – an award bestowed in recognition of innovative and courageous research projects. The prize money will allow the researchers to employ two doctoral students who will manufacture the materials and conduct experiments to test their effectiveness. One of the bacteria they are interested in combating is Pseudomonas aeruginosa; it is found in the soil and in humid places like bathrooms, and can result in weakened hospital patients contracting dangerous infections.

No magic formula

"There is probably no single magic formula that will be effective against all kinds of biofilm", says David Schleheck. Which is why he and his colleagues first want to gain a better understanding of how the porous nano surfaces with the bioreactive molecules work. The team then plans to explore how these miniature factories can be tailored to different bacteria and application sites. "For example, self-disinfecting surfaces would also be conceivable where the nano materials would only release their toxins when needed, i.e. when they come into contact with bacteria." The goal is to develop substances that target and destroy specific bacteria but are harmless for humans.

Konstanz Research School Chemical Biology (KoRS-CB)

Everything at the KoRS-CB graduate school at the University of Konstanz revolves around the life sciences. KoRS-CB offers an interdisciplinary PhD programme in the field of chemical biology. Students on the programme run their own research project, while at the same time receiving additional training in the form of lectures, seminars, retreats and courses to give them methodological and transferable skills.

www.chembiol.uni-konstanz.de