Mother Nature serves as an inspiration for the fight against hospital germs An almost germ-free hospital without disinfectant—is it possible? Hygiene is extremely important in hospitals, especially operating theatres must be sterile in order to prevent possible infections of patients. Generally, disinfectants are used for this purpose, which have sometimes considerable disadvantages...
...Over time, bacteria can develop resistance to these toxins or allergies arise or skin is damaged. Using the model of a dragonfly wing, researchers have developed a surface with tiny needles on which bacteria are killed en masse.
This dragonfly is the Australian species Diplacodes bipunctata, also called "wandering arrow". Their wings are covered with tiny needles, providing an effective means of defence against germs. The bacteria are impaled on the needles and killed.
This particular effect of killing bacteria was noticed by Elena Ivanova and her colleagues from the Swinburne University of Technology in Melbourne. They first suspected antibacterial substances on the wings as the cause, but upon closer examination of the transparent front wing under the microscope, they recognised the real reason. The front wing of the dragonfly Diplacodes bipunctata looked like a forest of sharp needles, each just 240 nanometres in length. A deadly trap for bacteria?
In the laboratory, biologists have put the wings to the test, bringing different types of bacteria in contact with the dragonfly wings. The needles slit the cell wall of each bacterium open. On average, the experiment reached the incredible number of 450,000 bacteria per cm2, which were killed as soon as they came into contact with the wings.
The researchers' goal is now to develop a material with similar properties. So-called black silicon was found to be promising. Black silicon is created by bombarding "normal" silicon with ions or ultra-short laser pulses. Its surface is covered with 500-nanometre needles, small enough to puncture bacterial cells. However, the surface feels completely smooth to people.
The germ problem in hospitals could be solved using such nanomaterials with microscopic needles. As is so often the case, nature provides effective role models and solutions—"Mother Nature" sometimes has the best ideas.
Source: http://www.pm-magazin.de
