Berkeley Lab-led research could guide the development of bacteria-resistant materials
The bacterium Staphylococcus Aureus (S. aureus) is a common source of infections that occur after surgeries involving prosthetic joints and artificial heart valves. The grape-shaped microorganism adheres to medical equipment, and if it gets inside the body, it can cause a serious and even life-threatening illness called a Staph infection. The recent discovery of drug-resistant strains of S. aureus makes matters even worse.
This scanning electron microscopy image reveals how Staphylococcus Aureus cells physically interact with a nanostructure. A bacterial cell (blue) is embedded inside the hollow nanopillar's hole and several cells cling to the nanopillar's curved walls. (Credit: Mofrad lab and the Nanomechanics Research Institute)
A Staph infection can’t start unless Staphylococcus cells first cling to a surface, however, which is why scientists are hard at work exploring bacteria-resistant materials as a line of defense. This research has now gone nanoscale, thanks to a team of researchers led by Berkeley Lab scientists. They investigated, for the first time, how individual S. aureus cells glom onto metallic nanostructures of various shapes and sizes that are not much bigger than the cells themselves.
They found that bacterial adhesion and survival rates vary depending on the nanostructure’s shape. Their work could lead to a more nuanced understanding of what makes a surface less inviting to bacteria.
“By understanding the preferences of bacteria during adhesion, medical implant devices can be fabricated to contain surface features immune to bacteria adhesion, without the requirement of any chemical modifications,” says Mohammad Mofrad, a faculty scientist in Berkeley Lab’s Physical Biosciences Division and a professor of Bioengineering and Mechanical Engineering at UC Berkeley.
Mofrad conducted the research with the Physical Biosciences Division’s Zeinab Jahed, the lead author of the study and a graduate student in Mofrad’s UC Berkeley Molecular Cell Biomechanics Laboratory, in collaboration with scientists from Canada’s University of Waterloo.
Their research was recently published online in the journal Biomaterials.
The scientists first used electron beam lithographic and electroplating techniques to fabricate nickel nanostructures of various shapes, including solid pillars, hollowed-out pillars, c-shaped pillars, and x-shaped columns. These features have outer diameters as small as 220 nanometers. They also created mushroom-shaped nanostructures with tiny stems and large overhangs.
They introduced S. aureus cells to these structures, gave the cells time to stick, and then rinsed the structures with deionized water to remove all but the most solidly bound bacteria.
Scanning electron microscopy revealed which shapes are the most effective at inhibiting bacterial adhesion. The scientists observed higher bacteria survival rates on the tubular-shaped pillars, where individual cells were partially embedded into the holes.
In contrast, pillars with no holes had the lowest survival rates.
The scientists also found that S. aureus cells can adhere to a wide range of surfaces. The cells not only adhere to horizontal surfaces, as expected, but to highly curved features, such as the sidewalls of pillars. The cells can also suspend from the overhangs of mushroom-shaped nanostructures.
“The bacteria seem to sense the nanotopography of the surface and form stronger adhesions on specific nanostructures,” says Jahed.
The research was supported by the Natural Sciences and Engineering Research Council of Canada and a National Science Foundation CAREER award.
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.
Dan Krotz | EurekAlert!
Fish recognize their prey by electric colors
13.11.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn
The dawn of a new era for genebanks - molecular characterisation of an entire genebank collection
13.11.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
13.11.2018 | Life Sciences
13.11.2018 | Life Sciences
13.11.2018 | Awards Funding