Heavy ions stop biofilms forming on polymer
doi:10.1038/nindia.2016.108 Published online 23 August 2016
Researchers have discovered that exposing polycarbonate polymer films to beams of iron ions can prevent biofilms of microbial cells forming on the film surfaces1.
Since polycarbonate is used in many areas, including nuclear physics, space, optics, electronics and medicine, this strategy could stop diseases spreading through pathogens growing on the surfaces of various devices.
To probe the anti-biofilm properties of iron ions, the researchers exposed polycarbonate films to iron-ion beams of two different energies. The iron ions decreased the molecular weight of the polymer films and roughened their surfaces by trapping air between water droplets and the film surface. In addition, the iron ions formed nanopores on the surface by breaking down molecules on the polymer surface.
The scientists tested the anti-biofilm properties of ion-treated polymer films and compared them with those of untreated polymer films by growing Salmonella typhi, a disease-causing bacterium, on both films. The bacteria formed biofilms on the unexposed polymer surface, whereas the ion-treated polymer film inhibited biofilm formation.
The nanopores on the polycarbonate surface prevented the bacteria from forming biofilms by generating bacteria-repelling effects such as repulsive, electrostatic and acid-base forces, the researchers say.
1. Joshi, R. P. et al. Anti-biofilm activity of Fe heavy ion irradiated polycarbonate. Nucl. Instrum. Meth. Phys. Res. B. 384, 6–13 (2016)