by • March 16, 2016 • No Comments
Keeping surfaces bacteria-free is particularly significant when it comes to medical devices and implants. In a move that may replace the use of biocidal coatings and antibiotic drugs in such applications, scientists have made a germ-repelling synthetic polymer inspired by the antibacterial powers of insect wings, that they say may form the basis of resilient new types of eye implants.
It was back in 2013 that a team of scientists took a microscope to cicada wings to reveal an array of nanoscale spikes. Whilst every was relatively blunt on its own, the team discovered this grid of studs may suspend bacterium that settles on the insect’s wings until it sagged into the gaps, some day rupturing over time and dying.
Hailed as the firstly known instance of a living organisms eradicating microbes exclusively via its own biomaterial, this neat trick of nature inspired a new way of looking at antibacterial surfaces. And now it seems to be bringing its firstly steps in the direction of practical applications.
“Other research groups have in addition made antibacterial nanopillar surfaces, but none of their approaches can be utilized on ordinary polymer surfaces or be scaled up easily,” says Albert F. Yee, Professor of chemical engineering and materials science at the University of California, Irvine.
Yee and his team turn it intod a flexible mold to replicate the cicada’s studs with the aim of crafting an artificial cornea that can not need a separate coating to deal with bacteria. They and so utilized the mold to turn it into a curved nanopillared surface via poly(methyl methacrylate) (PMMA), a material additional commonly known as Plexiglass or Lucite. The team was able-bodied to demonstrate that the matrix of small barbs was able-bodied to kill bacteria without harming other cells in the eye.
Whilst promising, the team wasn’t content with these first results. Through previous research it had learnt that the nanopillars on cicada wings can kill bacteria known as “gram-negative,” a group that comes with E. coli and Salmonella. But when faced with “gram-positive” bacteria that showcase thicker cell walls, such as Staphylococcus aureus, they are unable-bodied to eliminate the threat.
To solve this problem, the researchers are again turning to nature. Dragonfly wings in addition showcase nanopillar patterns that fend off microbes, but these are taller and skinnier, that enable-bodieds them to fend of gram-positive bacteria. The team is now working to return it into this effect on PMMA, but has encountered numerous hurdles along the way. The lean, brittle pillars tend to break when removed of the mold, that showcases billions of small cavities inside an area of only a few square inches.
In an take on to craft dragonfly-inspired antibacterial-surfaces, the team is testing out various chemical compositions to form the mold, and in addition incorporating fluorinated silane coatings that may assist free the pillars on removal. Meanwhile, the researchers have may already filed patents for the artificial cornea, with hopes of commencing animal trials this year.
“Our method is based on one made in the early 2000s for the semiconductor industry,” says Mary Nora Dickson, a graduate student in Yee’s lab. “It is robust, inexpensive and can be utilized in industrial production. So it can now be applied to medical devices that may improve people’s high end of life.”
The research can be presented at a meeting of the American Chemical Society.
Source: American Chemical Society
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by admin • November 28, 2016
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