posted on 2020-03-06, 15:52authored byNoemí Encinas, Ching-Yu Yang, Florian Geyer, Anke Kaltbeitzel, Philipp Baumli, Jonas Reinholz, Volker Mailänder, Hans-Jürgen Butt, Doris Vollmer
Biofilm
formation is most commonly combatted with antibiotics or biocides.
However, proven toxicity and increasing resistance of bacteria increase
the need for alternative strategies to prevent adhesion of bacteria
to surfaces. Chemical modification of the surfaces by tethering of
functional polymer brushes or films provides a route toward antifouling
coatings. Furthermore, nanorough or superhydrophobic surfaces can
delay biofilm formation. Here we show that submicrometer-sized roughness
can outweigh surface chemistry by testing the adhesion of E. coli to surfaces of different topography and wettability
over long exposure times (>7 days). Gram-negative and positive
bacterial strains are tested for comparison. We show that an irregular
three-dimensional layer of silicone nanofilaments suppresses bacterial
adhesion, both in the presence and absence of an air cushion. We hypothesize
that a 3D topography can delay biofilm formation (i) if bacteria do
not fit into the pores of the coating or (ii) if bending of the bacteria
is required to adhere. Thus, such a 3D topography offers an underestimated
possibility to design antibacterial surfaces that do not require biocides
or antibiotics.