Bacteria-resistant films could aid antimicrobial effect
Engineers at the MIT have created polymer-based ultrathin films that could be applied to medical devices and other surfaces to control microbe accumulation.
The researchers found that they could control the extent of bacterial adhesion to surfaces by manipulating the mechanical stiffness of polymer films called polyelectrolyte multilayers.
Stiffness has usually been overlooked in studies of how bacteria adhere to surfaces in favour of other traits such as surface charge, roughness, and attraction to or repulsion from water. The new work shows that stiffness should also be taken into account, said Krystyn Van Vliet, the Thomas Lord Assistant Professor of Materials Science and Engineering and the paper's anchor author.
The new films could be combined with current methods of repelling bacteria to boost their effectiveness, said Michael Rubner, an author of the paper and director of MIT's Center for Materials Science and Engineering.
Those methods include coating surfaces with antimicrobial chemicals or embedding metal nanoparticles into the surface, which disrupt the bacterial cell walls.
Jenny Lichter, graduate student in materials science and engineering, and Todd Thompson, a graduate student in the Division of Health Sciences and Technology, are joint lead authors of the paper. They note that the films could also be used on medical devices that go inside the body, such as stents and other cardiac implants.
"Once a foreign object enters into the body, if you can limit the number of bacteria going in with it, this may increase the chances that the immune system can defend against that infection," said Thompson.
Another possible application for the films is to promote growth of so-called "good bugs" by tuning the mechanical stiffness of the material on which these bacteria are cultured. These films could stimulate growth of bacteria needed for scientific study, medical testing, or industrial uses such as making ethanol.
The research was funded by the National Science Foundation, National Institutes of Health and the Arnold and Mabel Beckman Foundation Young Investigator Program.
Details of the research can be found in the Biomacromolecule published issue.